fix a link in skills.md

fix flaky tests
add docs
2026-01-04 07:59:13 +00:00 · 2025-12-23 15:09:23 +08:00 · 2025-12-23 14:50:47 +08:00 · 2025-12-23 10:53:09 +08:00 · 2025-12-23 10:24:57 +08:00 · 2025-12-22 16:00:57 +08:00
120 changed files with 10123 additions and 2770 deletions
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -2,6 +2,27 @@

 We would love to accept your patches and contributions to this project.

+## Before you begin
+
+### Sign our Contributor License Agreement
+
+Contributions to this project must be accompanied by a
+[Contributor License Agreement](https://cla.developers.google.com/about) (CLA).
+You (or your employer) retain the copyright to your contribution; this simply
+gives us permission to use and redistribute your contributions as part of the
+project.
+
+If you or your current employer have already signed the Google CLA (even if it
+was for a different project), you probably don't need to do it again.
+
+Visit <https://cla.developers.google.com/> to see your current agreements or to
+sign a new one.
+
+### Review our Community Guidelines
+
+This project follows [Google's Open Source Community
+Guidelines](https://opensource.google/conduct/).
+
 ## Contribution Process

 ### Code Reviews
@@ -53,6 +74,12 @@ Your PR should have a clear, descriptive title and a detailed description of the

 In the PR description, explain the "why" behind your changes and link to the relevant issue (e.g., `Fixes #123`).

+## Forking
+
+If you are forking the repository you will be able to run the Build, Test and Integration test workflows. However in order to make the integration tests run you'll need to add a [GitHub Repository Secret](https://docs.github.com/en/actions/security-for-github-actions/security-guides/using-secrets-in-github-actions#creating-secrets-for-a-repository) with a value of `GEMINI_API_KEY` and set that to a valid API key that you have available. Your key and secret are private to your repo; no one without access can see your key and you cannot see any secrets related to this repo.
+
+Additionally you will need to click on the `Actions` tab and enable workflows for your repository, you'll find it's the large blue button in the center of the screen.
+
 ## Development Setup and Workflow

 This section guides contributors on how to build, modify, and understand the development setup of this project.
@@ -71,8 +98,8 @@ This section guides contributors on how to build, modify, and understand the dev
 To clone the repository:

 ```bash
-git clone https://github.com/QwenLM/qwen-code.git # Or your fork's URL
-cd qwen-code
+git clone https://github.com/google-gemini/gemini-cli.git # Or your fork's URL
+cd gemini-cli
 ```

 To install dependencies defined in `package.json` as well as root dependencies:
@@ -91,9 +118,9 @@ This command typically compiles TypeScript to JavaScript, bundles assets, and pr

 ### Enabling Sandboxing

-[Sandboxing](#sandboxing) is highly recommended and requires, at a minimum, setting `QWEN_SANDBOX=true` in your `~/.env` and ensuring a sandboxing provider (e.g. `macOS Seatbelt`, `docker`, or `podman`) is available. See [Sandboxing](#sandboxing) for details.
+[Sandboxing](#sandboxing) is highly recommended and requires, at a minimum, setting `GEMINI_SANDBOX=true` in your `~/.env` and ensuring a sandboxing provider (e.g. `macOS Seatbelt`, `docker`, or `podman`) is available. See [Sandboxing](#sandboxing) for details.

-To build both the `qwen-code` CLI utility and the sandbox container, run `build:all` from the root directory:
+To build both the `gemini` CLI utility and the sandbox container, run `build:all` from the root directory:

 ```bash
 npm run build:all
@@ -103,13 +130,13 @@ To skip building the sandbox container, you can use `npm run build` instead.

 ### Running

-To start the Qwen Code application from the source code (after building), run the following command from the root directory:
+To start the Gemini CLI from the source code (after building), run the following command from the root directory:

 ```bash
 npm start
 ```

-If you'd like to run the source build outside of the qwen-code folder, you can utilize `npm link path/to/qwen-code/packages/cli` (see: [docs](https://docs.npmjs.com/cli/v9/commands/npm-link)) to run with `qwen-code`
+If you'd like to run the source build outside of the gemini-cli folder, you can utilize `npm link path/to/gemini-cli/packages/cli` (see: [docs](https://docs.npmjs.com/cli/v9/commands/npm-link)) or `alias gemini="node path/to/gemini-cli/packages/cli"` to run with `gemini`

 ### Running Tests

@@ -127,7 +154,7 @@ This will run tests located in the `packages/core` and `packages/cli` directorie

 #### Integration Tests

-The integration tests are designed to validate the end-to-end functionality of Qwen Code. They are not run as part of the default `npm run test` command.
+The integration tests are designed to validate the end-to-end functionality of the Gemini CLI. They are not run as part of the default `npm run test` command.

 To run the integration tests, use the following command:

@@ -182,61 +209,19 @@ npm run lint
 ### Coding Conventions

 - Please adhere to the coding style, patterns, and conventions used throughout the existing codebase.
+- Consult [QWEN.md](https://github.com/QwenLM/qwen-code/blob/main/QWEN.md) (typically found in the project root) for specific instructions related to AI-assisted development, including conventions for React, comments, and Git usage.
 - **Imports:** Pay special attention to import paths. The project uses ESLint to enforce restrictions on relative imports between packages.

 ### Project Structure

 - `packages/`: Contains the individual sub-packages of the project.
  - `cli/`: The command-line interface.
-  - `core/`: The core backend logic for Qwen Code.
+  - `core/`: The core backend logic for the Gemini CLI.
 - `docs/`: Contains all project documentation.
 - `scripts/`: Utility scripts for building, testing, and development tasks.

 For more detailed architecture, see `docs/architecture.md`.

-## Documentation Development
-
-This section describes how to develop and preview the documentation locally.
-
-### Prerequisites
-
-1. Ensure you have Node.js (version 18+) installed
-2. Have npm or yarn available
-
-### Setup Documentation Site Locally
-
-To work on the documentation and preview changes locally:
-
-1. Navigate to the `docs-site` directory:
-
-   ```bash
-   cd docs-site
-   ```
-
-2. Install dependencies:
-
-   ```bash
-   npm install
-   ```
-
-3. Link the documentation content from the main `docs` directory:
-
-   ```bash
-   npm run link
-   ```
-
-   This creates a symbolic link from `../docs` to `content` in the docs-site project, allowing the documentation content to be served by the Next.js site.
-
-4. Start the development server:
-
-   ```bash
-   npm run dev
-   ```
-
-5. Open [http://localhost:3000](http://localhost:3000) in your browser to see the documentation site with live updates as you make changes.
-
-Any changes made to the documentation files in the main `docs` directory will be reflected immediately in the documentation site.
-
 ## Debugging

 ### VS Code:
@@ -246,7 +231,7 @@ Any changes made to the documentation files in the main `docs` directory will be
    ```bash
    npm run debug
    ```
-    This command runs `node --inspect-brk dist/index.js` within the `packages/cli` directory, pausing execution until a debugger attaches. You can then open `chrome://inspect` in your Chrome browser to connect to the debugger.
+    This command runs `node --inspect-brk dist/gemini.js` within the `packages/cli` directory, pausing execution until a debugger attaches. You can then open `chrome://inspect` in your Chrome browser to connect to the debugger.
 2.  In VS Code, use the "Attach" launch configuration (found in `.vscode/launch.json`).

 Alternatively, you can use the "Launch Program" configuration in VS Code if you prefer to launch the currently open file directly, but 'F5' is generally recommended.
@@ -254,16 +239,16 @@ Alternatively, you can use the "Launch Program" configuration in VS Code if you
 To hit a breakpoint inside the sandbox container run:

 ```bash
-DEBUG=1 qwen-code
+DEBUG=1 gemini
 ```

-**Note:** If you have `DEBUG=true` in a project's `.env` file, it won't affect qwen-code due to automatic exclusion. Use `.qwen-code/.env` files for qwen-code specific debug settings.
+**Note:** If you have `DEBUG=true` in a project's `.env` file, it won't affect gemini-cli due to automatic exclusion. Use `.gemini/.env` files for gemini-cli specific debug settings.

 ### React DevTools

 To debug the CLI's React-based UI, you can use React DevTools. Ink, the library used for the CLI's interface, is compatible with React DevTools version 4.x.

-1.  **Start the Qwen Code application in development mode:**
+1.  **Start the Gemini CLI in development mode:**

    ```bash
    DEV=true npm start
@@ -285,10 +270,23 @@ To debug the CLI's React-based UI, you can use React DevTools. Ink, the library
    ```

    Your running CLI application should then connect to React DevTools.
+    ![](/docs/assets/connected_devtools.png)

 ## Sandboxing

-> TBD
+### macOS Seatbelt
+
+On macOS, `qwen` uses Seatbelt (`sandbox-exec`) under a `permissive-open` profile (see `packages/cli/src/utils/sandbox-macos-permissive-open.sb`) that restricts writes to the project folder but otherwise allows all other operations and outbound network traffic ("open") by default. You can switch to a `restrictive-closed` profile (see `packages/cli/src/utils/sandbox-macos-restrictive-closed.sb`) that declines all operations and outbound network traffic ("closed") by default by setting `SEATBELT_PROFILE=restrictive-closed` in your environment or `.env` file. Available built-in profiles are `{permissive,restrictive}-{open,closed,proxied}` (see below for proxied networking). You can also switch to a custom profile `SEATBELT_PROFILE=<profile>` if you also create a file `.qwen/sandbox-macos-<profile>.sb` under your project settings directory `.qwen`.
+
+### Container-based Sandboxing (All Platforms)
+
+For stronger container-based sandboxing on macOS or other platforms, you can set `GEMINI_SANDBOX=true|docker|podman|<command>` in your environment or `.env` file. The specified command (or if `true` then either `docker` or `podman`) must be installed on the host machine. Once enabled, `npm run build:all` will build a minimal container ("sandbox") image and `npm start` will launch inside a fresh instance of that container. The first build can take 20-30s (mostly due to downloading of the base image) but after that both build and start overhead should be minimal. Default builds (`npm run build`) will not rebuild the sandbox.
+
+Container-based sandboxing mounts the project directory (and system temp directory) with read-write access and is started/stopped/removed automatically as you start/stop Gemini CLI. Files created within the sandbox should be automatically mapped to your user/group on host machine. You can easily specify additional mounts, ports, or environment variables by setting `SANDBOX_{MOUNTS,PORTS,ENV}` as needed. You can also fully customize the sandbox for your projects by creating the files `.qwen/sandbox.Dockerfile` and/or `.qwen/sandbox.bashrc` under your project settings directory (`.qwen`) and running `qwen` with `BUILD_SANDBOX=1` to trigger building of your custom sandbox.
+
+#### Proxied Networking
+
+All sandboxing methods, including macOS Seatbelt using `*-proxied` profiles, support restricting outbound network traffic through a custom proxy server that can be specified as `GEMINI_SANDBOX_PROXY_COMMAND=<command>`, where `<command>` must start a proxy server that listens on `:::8877` for relevant requests. See `docs/examples/proxy-script.md` for a minimal proxy that only allows `HTTPS` connections to `example.com:443` (e.g. `curl https://example.com`) and declines all other requests. The proxy is started and stopped automatically alongside the sandbox.

 ## Manual Publish

--- a/10
+++ b/10
@@ -1,9 +1,9 @@
-# Makefile for qwen-code
+# Makefile for gemini-cli

 .PHONY: help install build build-sandbox build-all test lint format preflight clean start debug release run-npx create-alias

 help:
-	@echo "Makefile for qwen-code"
+	@echo "Makefile for gemini-cli"
 	@echo ""
 	@echo "Usage:"
 	@echo "  make install          - Install npm dependencies"
@@ -14,11 +14,11 @@ help:
 	@echo "  make format           - Format the code"
 	@echo "  make preflight        - Run formatting, linting, and tests"
 	@echo "  make clean            - Remove generated files"
-	@echo "  make start            - Start the Qwen Code CLI"
-	@echo "  make debug            - Start the Qwen Code CLI in debug mode"
+	@echo "  make start            - Start the Gemini CLI"
+	@echo "  make debug            - Start the Gemini CLI in debug mode"
 	@echo ""
 	@echo "  make run-npx          - Run the CLI using npx (for testing the published package)"
-	@echo "  make create-alias     - Create a 'qwen' alias for your shell"
+	@echo "  make create-alias     - Create a 'gemini' alias for your shell"

 install:
 	npm install
--- a/README.md
+++ b/README.md
@@ -1,152 +1,382 @@
+# Qwen Code
+
 <div align="center">

+![Qwen Code Screenshot](./docs/assets/qwen-screenshot.png)
+
 [![npm version](https://img.shields.io/npm/v/@qwen-code/qwen-code.svg)](https://www.npmjs.com/package/@qwen-code/qwen-code)
 [![License](https://img.shields.io/github/license/QwenLM/qwen-code.svg)](./LICENSE)
 [![Node.js Version](https://img.shields.io/badge/node-%3E%3D20.0.0-brightgreen.svg)](https://nodejs.org/)
 [![Downloads](https://img.shields.io/npm/dm/@qwen-code/qwen-code.svg)](https://www.npmjs.com/package/@qwen-code/qwen-code)

-**An open-source AI agent that lives in your terminal.**
+**AI-powered command-line workflow tool for developers**

-<a href="https://qwenlm.github.io/qwen-code-docs/zh/users/overview">中文</a> |
-<a href="https://qwenlm.github.io/qwen-code-docs/de/users/overview">Deutsch</a> |
-<a href="https://qwenlm.github.io/qwen-code-docs/fr/users/overview">français</a> |
-<a href="https://qwenlm.github.io/qwen-code-docs/ja/users/overview">日本語</a> |
-<a href="https://qwenlm.github.io/qwen-code-docs/ru/users/overview">Русский</a> |
-<a href="https://qwenlm.github.io/qwen-code-docs/pt-BR/users/overview">Português (Brasil)</a>
+[Installation](#installation) • [Quick Start](#quick-start) • [Features](#key-features) • [Documentation](./docs/) • [Contributing](./CONTRIBUTING.md)

 </div>

-Qwen Code is an open-source AI agent for the terminal, optimized for [Qwen3-Coder](https://github.com/QwenLM/Qwen3-Coder). It helps you understand large codebases, automate tedious work, and ship faster.
+<div align="center">
+  
+  <a href="https://qwenlm.github.io/qwen-code-docs/de/">Deutsch</a> | 
+  <a href="https://qwenlm.github.io/qwen-code-docs/fr">français</a> | 
+  <a href="https://qwenlm.github.io/qwen-code-docs/ja/">日本語</a> | 
+  <a href="https://qwenlm.github.io/qwen-code-docs/ru">Русский</a> | 
+  <a href="https://qwenlm.github.io/qwen-code-docs/zh/">中文</a>
+  
+</div>

-![](https://gw.alicdn.com/imgextra/i1/O1CN01D2DviS1wwtEtMwIzJ_!!6000000006373-2-tps-1600-900.png)
+Qwen Code is a powerful command-line AI workflow tool adapted from [**Gemini CLI**](https://github.com/google-gemini/gemini-cli), specifically optimized for [Qwen3-Coder](https://github.com/QwenLM/Qwen3-Coder) models. It enhances your development workflow with advanced code understanding, automated tasks, and intelligent assistance.

-## Why Qwen Code?
+## 💡 Free Options Available

- **OpenAI-compatible, OAuth free tier**: use an OpenAI-compatible API, or sign in with Qwen OAuth to get 2,000 free requests/day.
- **Open-source, co-evolving**: both the framework and the Qwen3-Coder model are open-source—and they ship and evolve together.
- **Agentic workflow, feature-rich**: rich built-in tools (Skills, SubAgents, Plan Mode) for a full agentic workflow and a Claude Code-like experience.
- **Terminal-first, IDE-friendly**: built for developers who live in the command line, with optional integration for VS Code and Zed.
+Get started with Qwen Code at no cost using any of these free options:
+
+### 🔥 Qwen OAuth (Recommended)
+
+- **2,000 requests per day** with no token limits
+- **60 requests per minute** rate limit
+- Simply run `qwen` and authenticate with your qwen.ai account
+- Automatic credential management and refresh
+- Use `/auth` command to switch to Qwen OAuth if you have initialized with OpenAI compatible mode
+
+### 🌏 Regional Free Tiers
+
+- **Mainland China**: ModelScope offers **2,000 free API calls per day**
+- **International**: OpenRouter provides **up to 1,000 free API calls per day** worldwide
+
+For detailed setup instructions, see [Authorization](#authorization).
+
+> [!WARNING]
+> **Token Usage Notice**: Qwen Code may issue multiple API calls per cycle, resulting in higher token usage (similar to Claude Code). We're actively optimizing API efficiency.
+
+## Key Features
+
+- **Code Understanding & Editing** - Query and edit large codebases beyond traditional context window limits
+- **Workflow Automation** - Automate operational tasks like handling pull requests and complex rebases
+- **Enhanced Parser** - Adapted parser specifically optimized for Qwen-Coder models
+- **Vision Model Support** - Automatically detect images in your input and seamlessly switch to vision-capable models for multimodal analysis

 ## Installation

-#### Prerequisites
+### Prerequisites
+
+Ensure you have [Node.js version 20](https://nodejs.org/en/download) or higher installed.

 ```bash
-# Node.js 20+
 curl -qL https://www.npmjs.com/install.sh | sh
 ```

-#### NPM (recommended)
+### Install from npm

 ```bash
 npm install -g @qwen-code/qwen-code@latest
+qwen --version
 ```

-#### Homebrew (macOS, Linux)
+### Install from source
+
+```bash
+git clone https://github.com/QwenLM/qwen-code.git
+cd qwen-code
+npm install
+npm install -g .
+```
+
+### Install globally with Homebrew (macOS/Linux)

 ```bash
 brew install qwen-code
 ```

+## VS Code Extension
+
+In addition to the CLI tool, Qwen Code also provides a **VS Code extension** that brings AI-powered coding assistance directly into your editor with features like file system operations, native diffing, interactive chat, and more.
+
+> 📦 The extension is currently in development. For installation, features, and development guide, see the [VS Code Extension README](./packages/vscode-ide-companion/README.md).
+
 ## Quick Start

 ```bash
-# Start Qwen Code (interactive)
+# Start Qwen Code
 qwen

-# Then, in the session:
-/help
-/auth
+# Example commands
+> Explain this codebase structure
+> Help me refactor this function
+> Generate unit tests for this module
 ```

-On first use, you'll be prompted to sign in. You can run `/auth` anytime to switch authentication methods.
+### Session Management

-Example prompts:
+Control your token usage with configurable session limits to optimize costs and performance.

-```text
-What does this project do?
-Explain the codebase structure.
-Help me refactor this function.
-Generate unit tests for this module.
+#### Configure Session Token Limit
+
+Create or edit `.qwen/settings.json` in your home directory:
+
+```json
+{
+  "sessionTokenLimit": 32000
+}
 ```

+#### Session Commands
+
+- **`/compress`** - Compress conversation history to continue within token limits
+- **`/clear`** - Clear all conversation history and start fresh
+- **`/stats`** - Check current token usage and limits
+
+> 📝 **Note**: Session token limit applies to a single conversation, not cumulative API calls.
+
+### Vision Model Configuration
+
+Qwen Code includes intelligent vision model auto-switching that detects images in your input and can automatically switch to vision-capable models for multimodal analysis. **This feature is enabled by default** - when you include images in your queries, you'll see a dialog asking how you'd like to handle the vision model switch.
+
+#### Skip the Switch Dialog (Optional)
+
+If you don't want to see the interactive dialog each time, configure the default behavior in your `.qwen/settings.json`:
+
+```json
+{
+  "experimental": {
+    "vlmSwitchMode": "once"
+  }
+}
+```
+
+**Available modes:**
+
+- **`"once"`** - Switch to vision model for this query only, then revert
+- **`"session"`** - Switch to vision model for the entire session
+- **`"persist"`** - Continue with current model (no switching)
+- **Not set** - Show interactive dialog each time (default)
+
+#### Command Line Override
+
+You can also set the behavior via command line:
+
+```bash
+# Switch once per query
+qwen --vlm-switch-mode once
+
+# Switch for entire session
+qwen --vlm-switch-mode session
+
+# Never switch automatically
+qwen --vlm-switch-mode persist
+```
+
+#### Disable Vision Models (Optional)
+
+To completely disable vision model support, add to your `.qwen/settings.json`:
+
+```json
+{
+  "experimental": {
+    "visionModelPreview": false
+  }
+}
+```
+
+> 💡 **Tip**: In YOLO mode (`--yolo`), vision switching happens automatically without prompts when images are detected.
+
+### Authorization
+
+Choose your preferred authentication method based on your needs:
+
+#### 1. Qwen OAuth (🚀 Recommended - Start in 30 seconds)
+
+The easiest way to get started - completely free with generous quotas:
+
+```bash
+# Just run this command and follow the browser authentication
+qwen
+```
+
+**What happens:**
+
+1. **Instant Setup**: CLI opens your browser automatically
+2. **One-Click Login**: Authenticate with your qwen.ai account
+3. **Automatic Management**: Credentials cached locally for future use
+4. **No Configuration**: Zero setup required - just start coding!
+
+**Free Tier Benefits:**
+
+- ✅ **2,000 requests/day** (no token counting needed)
+- ✅ **60 requests/minute** rate limit
+- ✅ **Automatic credential refresh**
+- ✅ **Zero cost** for individual users
+- ℹ️ **Note**: Model fallback may occur to maintain service quality
+
+#### 2. OpenAI-Compatible API
+
+Use API keys for OpenAI or other compatible providers:
+
+**Configuration Methods:**
+
+1. **Environment Variables**
+
+   ```bash
+   export OPENAI_API_KEY="your_api_key_here"
+   export OPENAI_BASE_URL="your_api_endpoint"
+   export OPENAI_MODEL="your_model_choice"
+   ```
+
+2. **Project `.env` File**
+   Create a `.env` file in your project root:
+   ```env
+   OPENAI_API_KEY=your_api_key_here
+   OPENAI_BASE_URL=your_api_endpoint
+   OPENAI_MODEL=your_model_choice
+   ```
+
+**API Provider Options**
+
+> ⚠️ **Regional Notice:**
+>
+> - **Mainland China**: Use Alibaba Cloud Bailian or ModelScope
+> - **International**: Use Alibaba Cloud ModelStudio or OpenRouter
+
 <details>
-<summary>Click to watch a demo video</summary>
+<summary><b>🇨🇳 For Users in Mainland China</b></summary>

-<video src="https://cloud.video.taobao.com/vod/HLfyppnCHplRV9Qhz2xSqeazHeRzYtG-EYJnHAqtzkQ.mp4" controls>
-Your browser does not support the video tag.
-</video>
+**Option 1: Alibaba Cloud Bailian** ([Apply for API Key](https://bailian.console.aliyun.com/))
+
+```bash
+export OPENAI_API_KEY="your_api_key_here"
+export OPENAI_BASE_URL="https://dashscope.aliyuncs.com/compatible-mode/v1"
+export OPENAI_MODEL="qwen3-coder-plus"
+```
+
+**Option 2: ModelScope (Free Tier)** ([Apply for API Key](https://modelscope.cn/docs/model-service/API-Inference/intro))
+
+- ✅ **2,000 free API calls per day**
+- ⚠️ Connect your Aliyun account to avoid authentication errors
+
+```bash
+export OPENAI_API_KEY="your_api_key_here"
+export OPENAI_BASE_URL="https://api-inference.modelscope.cn/v1"
+export OPENAI_MODEL="Qwen/Qwen3-Coder-480B-A35B-Instruct"
+```

 </details>

-## Authentication
+<details>
+<summary><b>🌍 For International Users</b></summary>

-Qwen Code supports two authentication methods:
-
- **Qwen OAuth (recommended & free)**: sign in with your `qwen.ai` account in a browser.
- **OpenAI-compatible API**: use `OPENAI_API_KEY` (and optionally a custom base URL / model).
-
-#### Qwen OAuth (recommended)
-
-Start `qwen`, then run:
+**Option 1: Alibaba Cloud ModelStudio** ([Apply for API Key](https://modelstudio.console.alibabacloud.com/))

 ```bash
-/auth
+export OPENAI_API_KEY="your_api_key_here"
+export OPENAI_BASE_URL="https://dashscope-intl.aliyuncs.com/compatible-mode/v1"
+export OPENAI_MODEL="qwen3-coder-plus"
 ```

-Choose **Qwen OAuth** and complete the browser flow. Your credentials are cached locally so you usually won't need to log in again.
-
-#### OpenAI-compatible API (API key)
-
-Environment variables (recommended for CI / headless environments):
+**Option 2: OpenRouter (Free Tier Available)** ([Apply for API Key](https://openrouter.ai/))

 ```bash
-export OPENAI_API_KEY="your-api-key-here"
-export OPENAI_BASE_URL="https://api.openai.com/v1"  # optional
-export OPENAI_MODEL="gpt-4o"                        # optional
+export OPENAI_API_KEY="your_api_key_here"
+export OPENAI_BASE_URL="https://openrouter.ai/api/v1"
+export OPENAI_MODEL="qwen/qwen3-coder:free"
 ```

-For details (including `.qwen/.env` loading and security notes), see the [authentication guide](https://qwenlm.github.io/qwen-code-docs/en/users/configuration/auth/).
+</details>

-## Usage
+## Usage Examples

-As an open-source terminal agent, you can use Qwen Code in four primary ways:
-
-1. Interactive mode (terminal UI)
-2. Headless mode (scripts, CI)
-3. IDE integration (VS Code, Zed)
-4. TypeScript SDK
-
-#### Interactive mode
+### 🔍 Explore Codebases

 ```bash
 cd your-project/
 qwen
+
+# Architecture analysis
+> Describe the main pieces of this system's architecture
+> What are the key dependencies and how do they interact?
+> Find all API endpoints and their authentication methods
 ```

-Run `qwen` in your project folder to launch the interactive terminal UI. Use `@` to reference local files (for example `@src/main.ts`).
-
-#### Headless mode
+### 💻 Code Development

 ```bash
-cd your-project/
-qwen -p "your question"
+# Refactoring
+> Refactor this function to improve readability and performance
+> Convert this class to use dependency injection
+> Split this large module into smaller, focused components
+
+# Code generation
+> Create a REST API endpoint for user management
+> Generate unit tests for the authentication module
+> Add error handling to all database operations
 ```

-Use `-p` to run Qwen Code without the interactive UI—ideal for scripts, automation, and CI/CD. Learn more: [Headless mode](https://qwenlm.github.io/qwen-code-docs/en/users/features/headless).
+### 🔄 Automate Workflows

-#### IDE integration
+```bash
+# Git automation
+> Analyze git commits from the last 7 days, grouped by feature
+> Create a changelog from recent commits
+> Find all TODO comments and create GitHub issues

-Use Qwen Code inside your editor (VS Code and Zed):
+# File operations
+> Convert all images in this directory to PNG format
+> Rename all test files to follow the *.test.ts pattern
+> Find and remove all console.log statements
+```

- [Use in VS Code](https://qwenlm.github.io/qwen-code-docs/en/users/integration-vscode/)
- [Use in Zed](https://qwenlm.github.io/qwen-code-docs/en/users/integration-zed/)
+### 🐛 Debugging & Analysis

-#### TypeScript SDK
+```bash
+# Performance analysis
+> Identify performance bottlenecks in this React component
+> Find all N+1 query problems in the codebase

-Build on top of Qwen Code with the TypeScript SDK:
+# Security audit
+> Check for potential SQL injection vulnerabilities
+> Find all hardcoded credentials or API keys
+```

- [Use the Qwen Code SDK](./packages/sdk-typescript/README.md)
+## Popular Tasks
+
+### 📚 Understand New Codebases
+
+```text
+> What are the core business logic components?
+> What security mechanisms are in place?
+> How does the data flow through the system?
+> What are the main design patterns used?
+> Generate a dependency graph for this module
+```
+
+### 🔨 Code Refactoring & Optimization
+
+```text
+> What parts of this module can be optimized?
+> Help me refactor this class to follow SOLID principles
+> Add proper error handling and logging
+> Convert callbacks to async/await pattern
+> Implement caching for expensive operations
+```
+
+### 📝 Documentation & Testing
+
+```text
+> Generate comprehensive JSDoc comments for all public APIs
+> Write unit tests with edge cases for this component
+> Create API documentation in OpenAPI format
+> Add inline comments explaining complex algorithms
+> Generate a README for this module
+```
+
+### 🚀 Development Acceleration
+
+```text
+> Set up a new Express server with authentication
+> Create a React component with TypeScript and tests
+> Implement a rate limiter middleware
+> Add database migrations for new schema
+> Configure CI/CD pipeline for this project
+```

 ## Commands & Shortcuts

@@ -156,7 +386,6 @@ Build on top of Qwen Code with the TypeScript SDK:
 - `/clear` - Clear conversation history
 - `/compress` - Compress history to save tokens
 - `/stats` - Show current session information
- `/bug` - Submit a bug report
 - `/exit` or `/quit` - Exit Qwen Code

 ### Keyboard Shortcuts
@@ -165,19 +394,6 @@ Build on top of Qwen Code with the TypeScript SDK:
 - `Ctrl+D` - Exit (on empty line)
 - `Up/Down` - Navigate command history

-> Learn more about [Commands](https://qwenlm.github.io/qwen-code-docs/en/users/features/commands/)
->
-> **Tip**: In YOLO mode (`--yolo`), vision switching happens automatically without prompts when images are detected. Learn more about [Approval Mode](https://qwenlm.github.io/qwen-code-docs/en/users/features/approval-mode/)
-
-## Configuration
-
-Qwen Code can be configured via `settings.json`, environment variables, and CLI flags.
-
- **User settings**: `~/.qwen/settings.json`
- **Project settings**: `.qwen/settings.json`
-
-See [settings](https://qwenlm.github.io/qwen-code-docs/en/users/configuration/settings/) for available options and precedence.
-
 ## Benchmark Results

 ### Terminal-Bench Performance
@@ -187,18 +403,24 @@ See [settings](https://qwenlm.github.io/qwen-code-docs/en/users/configuration/se
 | Qwen Code | Qwen3-Coder-480A35 | 37.5%    |
 | Qwen Code | Qwen3-Coder-30BA3B | 31.3%    |

-## Ecosystem
+## Development & Contributing

-Looking for a graphical interface?
+See [CONTRIBUTING.md](./CONTRIBUTING.md) to learn how to contribute to the project.

- [**Gemini CLI Desktop**](https://github.com/Piebald-AI/gemini-cli-desktop) A cross-platform desktop/web/mobile UI for Qwen Code
+For detailed authentication setup, see the [authentication guide](./docs/cli/authentication.md).

 ## Troubleshooting

-If you encounter issues, check the [troubleshooting guide](https://qwenlm.github.io/qwen-code-docs/en/users/support/troubleshooting/).
-
-To report a bug from within the CLI, run `/bug` and include a short title and repro steps.
+If you encounter issues, check the [troubleshooting guide](docs/troubleshooting.md).

 ## Acknowledgments

 This project is based on [Google Gemini CLI](https://github.com/google-gemini/gemini-cli). We acknowledge and appreciate the excellent work of the Gemini CLI team. Our main contribution focuses on parser-level adaptations to better support Qwen-Coder models.
+
+## License
+
+[LICENSE](./LICENSE)
+
+## Star History
+
+[![Star History Chart](https://api.star-history.com/svg?repos=QwenLM/qwen-code&type=Date)](https://www.star-history.com/#QwenLM/qwen-code&Date)
--- a/docs/users/configuration/settings.md
+++ b/docs/users/configuration/settings.md
@@ -43,6 +43,7 @@ Qwen Code uses JSON settings files for persistent configuration. There are four
 In addition to a project settings file, a project's `.qwen` directory can contain other project-specific files related to Qwen Code's operation, such as:

 - [Custom sandbox profiles](../features/sandbox) (e.g. `.qwen/sandbox-macos-custom.sb`, `.qwen/sandbox.Dockerfile`).
+- [Agent Skills](../features/skills) (experimental) under `.qwen/skills/` (each Skill is a directory containing a `SKILL.md`).

 ### Available settings in `settings.json`

@@ -380,6 +381,8 @@ Arguments passed directly when running the CLI can override other configurations
 | `--telemetry-otlp-protocol`  |       | Sets the OTLP protocol for telemetry (`grpc` or `http`).                                                                                                                                |                                        | Defaults to `grpc`. See [telemetry](../../developers/development/telemetry) for more information.                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
 | `--telemetry-log-prompts`    |       | Enables logging of prompts for telemetry.                                                                                                                                               |                                        | See [telemetry](../../developers/development/telemetry) for more information.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
 | `--checkpointing`            |       | Enables [checkpointing](../features/checkpointing).                                                                                                                                     |                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| `--experimental-acp`         |       | Enables ACP mode (Agent Control Protocol). Useful for IDE/editor integrations like [Zed](../integration-zed).                                                                           |                                        | Experimental.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
+| `--experimental-skills`      |       | Enables experimental [Agent Skills](../features/skills) (registers the `skill` tool and loads Skills from `.qwen/skills/` and `~/.qwen/skills/`).                                       |                                        | Experimental.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
 | `--extensions`               | `-e`  | Specifies a list of extensions to use for the session.                                                                                                                                  | Extension names                        | If not provided, all available extensions are used. Use the special term `qwen -e none` to disable all extensions. Example: `qwen -e my-extension -e my-other-extension`                                                                                                                                                                                                                                                                                                                                                                                        |
 | `--list-extensions`          | `-l`  | Lists all available extensions and exits.                                                                                                                                               |                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
 | `--proxy`                    |       | Sets the proxy for the CLI.                                                                                                                                                             | Proxy URL                              | Example: `--proxy http://localhost:7890`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
--- a/docs/users/features/_meta.ts
+++ b/docs/users/features/_meta.ts
@@ -1,6 +1,7 @@
 export default {
  commands: 'Commands',
  'sub-agents': 'SubAgents',
+  skills: 'Skills (Experimental)',
  headless: 'Headless Mode',
  checkpointing: {
    display: 'hidden',
--- a/docs/users/features/headless.md
+++ b/docs/users/features/headless.md
@@ -189,19 +189,20 @@ qwen -p "Write code" --output-format stream-json --include-partial-messages | jq

 Key command-line options for headless usage:

-| Option                       | Description                                         | Example                                                                  |
-| ---------------------------- | --------------------------------------------------- | ------------------------------------------------------------------------ |
-| `--prompt`, `-p`             | Run in headless mode                                | `qwen -p "query"`                                                        |
-| `--output-format`, `-o`      | Specify output format (text, json, stream-json)     | `qwen -p "query" --output-format json`                                   |
-| `--input-format`             | Specify input format (text, stream-json)            | `qwen --input-format text --output-format stream-json`                   |
-| `--include-partial-messages` | Include partial messages in stream-json output      | `qwen -p "query" --output-format stream-json --include-partial-messages` |
-| `--debug`, `-d`              | Enable debug mode                                   | `qwen -p "query" --debug`                                                |
-| `--all-files`, `-a`          | Include all files in context                        | `qwen -p "query" --all-files`                                            |
-| `--include-directories`      | Include additional directories                      | `qwen -p "query" --include-directories src,docs`                         |
-| `--yolo`, `-y`               | Auto-approve all actions                            | `qwen -p "query" --yolo`                                                 |
-| `--approval-mode`            | Set approval mode                                   | `qwen -p "query" --approval-mode auto_edit`                              |
-| `--continue`                 | Resume the most recent session for this project     | `qwen --continue -p "Pick up where we left off"`                         |
-| `--resume [sessionId]`       | Resume a specific session (or choose interactively) | `qwen --resume 123e... -p "Finish the refactor"`                         |
+| Option                       | Description                                             | Example                                                                  |
+| ---------------------------- | ------------------------------------------------------- | ------------------------------------------------------------------------ |
+| `--prompt`, `-p`             | Run in headless mode                                    | `qwen -p "query"`                                                        |
+| `--output-format`, `-o`      | Specify output format (text, json, stream-json)         | `qwen -p "query" --output-format json`                                   |
+| `--input-format`             | Specify input format (text, stream-json)                | `qwen --input-format text --output-format stream-json`                   |
+| `--include-partial-messages` | Include partial messages in stream-json output          | `qwen -p "query" --output-format stream-json --include-partial-messages` |
+| `--debug`, `-d`              | Enable debug mode                                       | `qwen -p "query" --debug`                                                |
+| `--all-files`, `-a`          | Include all files in context                            | `qwen -p "query" --all-files`                                            |
+| `--include-directories`      | Include additional directories                          | `qwen -p "query" --include-directories src,docs`                         |
+| `--yolo`, `-y`               | Auto-approve all actions                                | `qwen -p "query" --yolo`                                                 |
+| `--approval-mode`            | Set approval mode                                       | `qwen -p "query" --approval-mode auto_edit`                              |
+| `--continue`                 | Resume the most recent session for this project         | `qwen --continue -p "Pick up where we left off"`                         |
+| `--resume [sessionId]`       | Resume a specific session (or choose interactively)     | `qwen --resume 123e... -p "Finish the refactor"`                         |
+| `--experimental-skills`      | Enable experimental Skills (registers the `skill` tool) | `qwen --experimental-skills -p "What Skills are available?"`             |

 For complete details on all available configuration options, settings files, and environment variables, see the [Configuration Guide](../configuration/settings).

--- a/docs/users/features/skills.md
+++ b/docs/users/features/skills.md
@@ -0,0 +1,282 @@
+# Agent Skills (Experimental)
+
+> Create, manage, and share Skills to extend Qwen Code’s capabilities.
+
+This guide shows you how to create, use, and manage Agent Skills in **Qwen Code**. Skills are modular capabilities that extend the model’s effectiveness through organized folders containing instructions (and optionally scripts/resources).
+
+> [!note]
+>
+> Skills are currently **experimental** and must be enabled with `--experimental-skills`.
+
+## Prerequisites
+
+- Qwen Code (recent version)
+- Run with the experimental flag enabled:
+
+```bash
+qwen --experimental-skills
+```
+
+- Basic familiarity with Qwen Code ([Quickstart](../quickstart.md))
+
+## What are Agent Skills?
+
+Agent Skills package expertise into discoverable capabilities. Each Skill consists of a `SKILL.md` file with instructions that the model can load when relevant, plus optional supporting files like scripts and templates.
+
+### How Skills are invoked
+
+Skills are **model-invoked** — the model autonomously decides when to use them based on your request and the Skill’s description. This is different from slash commands, which are **user-invoked** (you explicitly type `/command`).
+
+### Benefits
+
+- Extend Qwen Code for your workflows
+- Share expertise across your team via git
+- Reduce repetitive prompting
+- Compose multiple Skills for complex tasks
+
+## Create a Skill
+
+Skills are stored as directories containing a `SKILL.md` file.
+
+### Personal Skills
+
+Personal Skills are available across all your projects. Store them in `~/.qwen/skills/`:
+
+```bash
+mkdir -p ~/.qwen/skills/my-skill-name
+```
+
+Use personal Skills for:
+
+- Your individual workflows and preferences
+- Experimental Skills you’re developing
+- Personal productivity helpers
+
+### Project Skills
+
+Project Skills are shared with your team. Store them in `.qwen/skills/` within your project:
+
+```bash
+mkdir -p .qwen/skills/my-skill-name
+```
+
+Use project Skills for:
+
+- Team workflows and conventions
+- Project-specific expertise
+- Shared utilities and scripts
+
+Project Skills can be checked into git and automatically become available to teammates.
+
+## Write `SKILL.md`
+
+Create a `SKILL.md` file with YAML frontmatter and Markdown content:
+
+```yaml
+---
+name: your-skill-name
+description: Brief description of what this Skill does and when to use it
+---
+
+# Your Skill Name
+
+## Instructions
+Provide clear, step-by-step guidance for Qwen Code.
+
+## Examples
+Show concrete examples of using this Skill.
+```
+
+### Field requirements
+
+Qwen Code currently validates that:
+
+- `name` is a non-empty string
+- `description` is a non-empty string
+
+Recommended conventions (not strictly enforced yet):
+
+- Use lowercase letters, numbers, and hyphens in `name`
+- Make `description` specific: include both **what** the Skill does and **when** to use it (key words users will naturally mention)
+
+## Add supporting files
+
+Create additional files alongside `SKILL.md`:
+
+```text
+my-skill/
+├── SKILL.md (required)
+├── reference.md (optional documentation)
+├── examples.md (optional examples)
+├── scripts/
+│   └── helper.py (optional utility)
+└── templates/
+    └── template.txt (optional template)
+```
+
+Reference these files from `SKILL.md`:
+
+````markdown
+For advanced usage, see [reference.md](reference.md).
+
+Run the helper script:
+
+```bash
+python scripts/helper.py input.txt
+```
+````
+
+## View available Skills
+
+When `--experimental-skills` is enabled, Qwen Code discovers Skills from:
+
+- Personal Skills: `~/.qwen/skills/`
+- Project Skills: `.qwen/skills/`
+
+To view available Skills, ask Qwen Code directly:
+
+```text
+What Skills are available?
+```
+
+Or inspect the filesystem:
+
+```bash
+# List personal Skills
+ls ~/.qwen/skills/
+
+# List project Skills (if in a project directory)
+ls .qwen/skills/
+
+# View a specific Skill’s content
+cat ~/.qwen/skills/my-skill/SKILL.md
+```
+
+## Test a Skill
+
+After creating a Skill, test it by asking questions that match your description.
+
+Example: if your description mentions “PDF files”:
+
+```text
+Can you help me extract text from this PDF?
+```
+
+The model autonomously decides to use your Skill if it matches the request — you don’t need to explicitly invoke it.
+
+## Debug a Skill
+
+If Qwen Code doesn’t use your Skill, check these common issues:
+
+### Make the description specific
+
+Too vague:
+
+```yaml
+description: Helps with documents
+```
+
+Specific:
+
+```yaml
+description: Extract text and tables from PDF files, fill forms, merge documents. Use when working with PDFs, forms, or document extraction.
+```
+
+### Verify file path
+
+- Personal Skills: `~/.qwen/skills/<skill-name>/SKILL.md`
+- Project Skills: `.qwen/skills/<skill-name>/SKILL.md`
+
+```bash
+# Personal
+ls ~/.qwen/skills/my-skill/SKILL.md
+
+# Project
+ls .qwen/skills/my-skill/SKILL.md
+```
+
+### Check YAML syntax
+
+Invalid YAML prevents the Skill metadata from loading correctly.
+
+```bash
+cat SKILL.md | head -n 15
+```
+
+Ensure:
+
+- Opening `---` on line 1
+- Closing `---` before Markdown content
+- Valid YAML syntax (no tabs, correct indentation)
+
+### View errors
+
+Run Qwen Code with debug mode to see Skill loading errors:
+
+```bash
+qwen --experimental-skills --debug
+```
+
+## Share Skills with your team
+
+You can share Skills through project repositories:
+
+1. Add the Skill under `.qwen/skills/`
+2. Commit and push
+3. Teammates pull the changes and run with `--experimental-skills`
+
+```bash
+git add .qwen/skills/
+git commit -m "Add team Skill for PDF processing"
+git push
+```
+
+## Update a Skill
+
+Edit `SKILL.md` directly:
+
+```bash
+# Personal Skill
+code ~/.qwen/skills/my-skill/SKILL.md
+
+# Project Skill
+code .qwen/skills/my-skill/SKILL.md
+```
+
+Changes take effect the next time you start Qwen Code. If Qwen Code is already running, restart it to load the updates.
+
+## Remove a Skill
+
+Delete the Skill directory:
+
+```bash
+# Personal
+rm -rf ~/.qwen/skills/my-skill
+
+# Project
+rm -rf .qwen/skills/my-skill
+git commit -m "Remove unused Skill"
+```
+
+## Best practices
+
+### Keep Skills focused
+
+One Skill should address one capability:
+
+- Focused: “PDF form filling”, “Excel analysis”, “Git commit messages”
+- Too broad: “Document processing” (split into smaller Skills)
+
+### Write clear descriptions
+
+Help the model discover when to use Skills by including specific triggers:
+
+```yaml
+description: Analyze Excel spreadsheets, create pivot tables, and generate charts. Use when working with Excel files, spreadsheets, or .xlsx data.
+```
+
+### Test with your team
+
+- Does the Skill activate when expected?
+- Are the instructions clear?
+- Are there missing examples or edge cases?
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@qwen-code/qwen-code",
-  "version": "0.6.0-preview.0",
+  "version": "0.6.0",
  "engines": {
    "node": ">=20.0.0"
  },
@@ -13,11 +13,14 @@
    "url": "git+https://github.com/QwenLM/qwen-code.git"
  },
  "config": {
-    "sandboxImageUri": "ghcr.io/qwenlm/qwen-code:0.6.0-preview.0"
+    "sandboxImageUri": "ghcr.io/qwenlm/qwen-code:0.6.0"
  },
  "scripts": {
    "start": "cross-env node scripts/start.js",
    "debug": "cross-env DEBUG=1 node --inspect-brk scripts/start.js",
+    "auth:npm": "npx google-artifactregistry-auth",
+    "auth:docker": "gcloud auth configure-docker us-west1-docker.pkg.dev",
+    "auth": "npm run auth:npm && npm run auth:docker",
    "generate": "node scripts/generate-git-commit-info.js",
    "build": "node scripts/build.js",
    "build-and-start": "npm run build && npm run start",
@@ -92,6 +95,7 @@
    "eslint-plugin-react-hooks": "^5.2.0",
    "glob": "^10.5.0",
    "globals": "^16.0.0",
+    "google-artifactregistry-auth": "^3.4.0",
    "husky": "^9.1.7",
    "json": "^11.0.0",
    "lint-staged": "^16.1.6",
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@qwen-code/qwen-code",
-  "version": "0.6.0-preview.0",
+  "version": "0.6.0",
  "description": "Qwen Code",
  "repository": {
    "type": "git",
@@ -33,13 +33,13 @@
    "dist"
  ],
  "config": {
-    "sandboxImageUri": "ghcr.io/qwenlm/qwen-code:0.6.0-preview.0"
+    "sandboxImageUri": "ghcr.io/qwenlm/qwen-code:0.6.0"
  },
  "dependencies": {
-    "@google/genai": "1.30.0",
+    "@google/genai": "1.16.0",
    "@iarna/toml": "^2.2.5",
    "@qwen-code/qwen-code-core": "file:../core",
-    "@modelcontextprotocol/sdk": "^1.25.1",
+    "@modelcontextprotocol/sdk": "^1.15.1",
    "@types/update-notifier": "^6.0.8",
    "ansi-regex": "^6.2.2",
    "command-exists": "^1.2.9",
--- a/packages/cli/src/config/auth.ts
+++ b/packages/cli/src/config/auth.ts
@@ -26,23 +26,5 @@ export function validateAuthMethod(authMethod: string): string | null {
    return null;
  }

-  if (authMethod === AuthType.USE_GEMINI) {
-    const hasApiKey = process.env['GEMINI_API_KEY'];
-    if (!hasApiKey) {
-      return 'GEMINI_API_KEY environment variable not found. Please set it in your .env file or environment variables.';
-    }
-    return null;
-  }
-
-  if (authMethod === AuthType.USE_VERTEX_AI) {
-    const hasApiKey = process.env['GOOGLE_API_KEY'];
-    if (!hasApiKey) {
-      return 'GOOGLE_API_KEY environment variable not found. Please set it in your .env file or environment variables.';
-    }
-
-    process.env['GOOGLE_GENAI_USE_VERTEXAI'] = 'true';
-    return null;
-  }
-
  return 'Invalid auth method selected.';
 }
--- a/packages/cli/src/config/config.ts
+++ b/packages/cli/src/config/config.ts
@@ -112,6 +112,7 @@ export interface CliArgs {
  allowedMcpServerNames: string[] | undefined;
  allowedTools: string[] | undefined;
  experimentalAcp: boolean | undefined;
+  experimentalSkills: boolean | undefined;
  extensions: string[] | undefined;
  listExtensions: boolean | undefined;
  openaiLogging: boolean | undefined;
@@ -307,6 +308,11 @@ export async function parseArguments(settings: Settings): Promise<CliArgs> {
          type: 'boolean',
          description: 'Starts the agent in ACP mode',
        })
+        .option('experimental-skills', {
+          type: 'boolean',
+          description: 'Enable experimental Skills feature',
+          default: false,
+        })
        .option('channel', {
          type: 'string',
          choices: ['VSCode', 'ACP', 'SDK', 'CI'],
@@ -460,12 +466,7 @@ export async function parseArguments(settings: Settings): Promise<CliArgs> {
        })
        .option('auth-type', {
          type: 'string',
-          choices: [
-            AuthType.USE_OPENAI,
-            AuthType.QWEN_OAUTH,
-            AuthType.USE_GEMINI,
-            AuthType.USE_VERTEX_AI,
-          ],
+          choices: [AuthType.USE_OPENAI, AuthType.QWEN_OAUTH],
          description: 'Authentication type',
        })
        .deprecateOption(
@@ -956,6 +957,7 @@ export async function loadCliConfig(
    maxSessionTurns:
      argv.maxSessionTurns ?? settings.model?.maxSessionTurns ?? -1,
    experimentalZedIntegration: argv.experimentalAcp || false,
+    experimentalSkills: argv.experimentalSkills || false,
    listExtensions: argv.listExtensions || false,
    extensions: allExtensions,
    blockedMcpServers,
--- a/packages/cli/src/gemini.test.tsx
+++ b/packages/cli/src/gemini.test.tsx
@@ -461,6 +461,7 @@ describe('gemini.tsx main function kitty protocol', () => {
      allowedMcpServerNames: undefined,
      allowedTools: undefined,
      experimentalAcp: undefined,
+      experimentalSkills: undefined,
      extensions: undefined,
      listExtensions: undefined,
      openaiLogging: undefined,
--- a/packages/cli/src/gemini.tsx
+++ b/packages/cli/src/gemini.tsx
@@ -4,8 +4,13 @@
 * SPDX-License-Identifier: Apache-2.0
 */

-import type { Config, AuthType } from '@qwen-code/qwen-code-core';
-import { InputFormat, logUserPrompt } from '@qwen-code/qwen-code-core';
+import type { Config } from '@qwen-code/qwen-code-core';
+import {
+  AuthType,
+  getOauthClient,
+  InputFormat,
+  logUserPrompt,
+} from '@qwen-code/qwen-code-core';
 import { render } from 'ink';
 import dns from 'node:dns';
 import os from 'node:os';
@@ -394,6 +399,15 @@ export async function main() {
      initializationResult = await initializeApp(config, settings);
    }

+    if (
+      settings.merged.security?.auth?.selectedType ===
+        AuthType.LOGIN_WITH_GOOGLE &&
+      config.isBrowserLaunchSuppressed()
+    ) {
+      // Do oauth before app renders to make copying the link possible.
+      await getOauthClient(settings.merged.security.auth.selectedType, config);
+    }
+
    if (config.getExperimentalZedIntegration()) {
      return runAcpAgent(config, settings, extensions, argv);
    }
--- a/packages/cli/src/nonInteractive/io/BaseJsonOutputAdapter.ts
+++ b/packages/cli/src/nonInteractive/io/BaseJsonOutputAdapter.ts
@@ -610,6 +610,8 @@ export abstract class BaseJsonOutputAdapter {
        const errorText = parseAndFormatApiError(
          event.value.error,
          this.config.getContentGeneratorConfig()?.authType,
+          undefined,
+          this.config.getModel(),
        );
        this.appendText(state, errorText, null);
        break;
--- a/packages/cli/src/nonInteractiveCli.ts
+++ b/packages/cli/src/nonInteractiveCli.ts
@@ -221,6 +221,8 @@ export async function runNonInteractive(
              const errorText = parseAndFormatApiError(
                event.value.error,
                config.getContentGeneratorConfig()?.authType,
+                undefined,
+                config.getModel(),
              );
              process.stderr.write(`${errorText}\n`);
            }
--- a/packages/cli/src/services/McpPromptLoader.test.ts
+++ b/packages/cli/src/services/McpPromptLoader.test.ts
@@ -28,7 +28,7 @@ const mockPrompt = {
    { name: 'trail', required: false, description: "The animal's trail." },
  ],
  invoke: vi.fn().mockResolvedValue({
-    messages: [{ content: { type: 'text', text: 'Hello, world!' } }],
+    messages: [{ content: { text: 'Hello, world!' } }],
  }),
 };

--- a/packages/cli/src/services/McpPromptLoader.ts
+++ b/packages/cli/src/services/McpPromptLoader.ts
@@ -123,10 +123,7 @@ export class McpPromptLoader implements ICommandLoader {
                };
              }

-              const firstMessage = result.messages?.[0];
-              const content = firstMessage?.content;
-
-              if (content?.type !== 'text') {
+              if (!result.messages?.[0]?.content?.['text']) {
                return {
                  type: 'message',
                  messageType: 'error',
@@ -137,7 +134,7 @@ export class McpPromptLoader implements ICommandLoader {

              return {
                type: 'submit_prompt',
-                content: JSON.stringify(content.text),
+                content: JSON.stringify(result.messages[0].content.text),
              };
            } catch (error) {
              return {
--- a/packages/cli/src/ui/AppContainer.test.tsx
+++ b/packages/cli/src/ui/AppContainer.test.tsx
@@ -23,6 +23,7 @@ import {
 } from '@qwen-code/qwen-code-core';
 import type { LoadedSettings } from '../config/settings.js';
 import type { InitializationResult } from '../core/initializer.js';
+import { useQuotaAndFallback } from './hooks/useQuotaAndFallback.js';
 import { UIStateContext, type UIState } from './contexts/UIStateContext.js';
 import {
  UIActionsContext,
@@ -55,6 +56,7 @@ vi.mock('./App.js', () => ({
  App: TestContextConsumer,
 }));

+vi.mock('./hooks/useQuotaAndFallback.js');
 vi.mock('./hooks/useHistoryManager.js');
 vi.mock('./hooks/useThemeCommand.js');
 vi.mock('./auth/useAuth.js');
@@ -120,6 +122,7 @@ describe('AppContainer State Management', () => {
  let mockInitResult: InitializationResult;

  // Create typed mocks for all hooks
+  const mockedUseQuotaAndFallback = useQuotaAndFallback as Mock;
  const mockedUseHistory = useHistory as Mock;
  const mockedUseThemeCommand = useThemeCommand as Mock;
  const mockedUseAuthCommand = useAuthCommand as Mock;
@@ -161,6 +164,10 @@ describe('AppContainer State Management', () => {
    capturedUIActions = null!;

    // **Provide a default return value for EVERY mocked hook.**
+    mockedUseQuotaAndFallback.mockReturnValue({
+      proQuotaRequest: null,
+      handleProQuotaChoice: vi.fn(),
+    });
    mockedUseHistory.mockReturnValue({
      history: [],
      addItem: vi.fn(),
@@ -560,6 +567,75 @@ describe('AppContainer State Management', () => {
    });
  });

+  describe('Quota and Fallback Integration', () => {
+    it('passes a null proQuotaRequest to UIStateContext by default', () => {
+      // The default mock from beforeEach already sets proQuotaRequest to null
+      render(
+        <AppContainer
+          config={mockConfig}
+          settings={mockSettings}
+          version="1.0.0"
+          initializationResult={mockInitResult}
+        />,
+      );
+
+      // Assert that the context value is as expected
+      expect(capturedUIState.proQuotaRequest).toBeNull();
+    });
+
+    it('passes a valid proQuotaRequest to UIStateContext when provided by the hook', () => {
+      // Arrange: Create a mock request object that a UI dialog would receive
+      const mockRequest = {
+        failedModel: 'gemini-pro',
+        fallbackModel: 'gemini-flash',
+        resolve: vi.fn(),
+      };
+      mockedUseQuotaAndFallback.mockReturnValue({
+        proQuotaRequest: mockRequest,
+        handleProQuotaChoice: vi.fn(),
+      });
+
+      // Act: Render the container
+      render(
+        <AppContainer
+          config={mockConfig}
+          settings={mockSettings}
+          version="1.0.0"
+          initializationResult={mockInitResult}
+        />,
+      );
+
+      // Assert: The mock request is correctly passed through the context
+      expect(capturedUIState.proQuotaRequest).toEqual(mockRequest);
+    });
+
+    it('passes the handleProQuotaChoice function to UIActionsContext', () => {
+      // Arrange: Create a mock handler function
+      const mockHandler = vi.fn();
+      mockedUseQuotaAndFallback.mockReturnValue({
+        proQuotaRequest: null,
+        handleProQuotaChoice: mockHandler,
+      });
+
+      // Act: Render the container
+      render(
+        <AppContainer
+          config={mockConfig}
+          settings={mockSettings}
+          version="1.0.0"
+          initializationResult={mockInitResult}
+        />,
+      );
+
+      // Assert: The action in the context is the mock handler we provided
+      expect(capturedUIActions.handleProQuotaChoice).toBe(mockHandler);
+
+      // You can even verify that the plumbed function is callable
+      capturedUIActions.handleProQuotaChoice('auth');
+      expect(mockHandler).toHaveBeenCalledWith('auth');
+    });
+  });
+
  describe('Terminal Title Update Feature', () => {
    beforeEach(() => {
      // Reset mock stdout for each test
--- a/packages/cli/src/ui/AppContainer.tsx
+++ b/packages/cli/src/ui/AppContainer.tsx
@@ -32,6 +32,7 @@ import {
  type Config,
  type IdeInfo,
  type IdeContext,
+  type UserTierId,
  DEFAULT_GEMINI_FLASH_MODEL,
  IdeClient,
  ideContextStore,
@@ -47,6 +48,7 @@ import { useHistory } from './hooks/useHistoryManager.js';
 import { useMemoryMonitor } from './hooks/useMemoryMonitor.js';
 import { useThemeCommand } from './hooks/useThemeCommand.js';
 import { useAuthCommand } from './auth/useAuth.js';
+import { useQuotaAndFallback } from './hooks/useQuotaAndFallback.js';
 import { useEditorSettings } from './hooks/useEditorSettings.js';
 import { useSettingsCommand } from './hooks/useSettingsCommand.js';
 import { useModelCommand } from './hooks/useModelCommand.js';
@@ -190,6 +192,8 @@ export const AppContainer = (props: AppContainerProps) => {

  const [currentModel, setCurrentModel] = useState(getEffectiveModel());

+  const [userTier] = useState<UserTierId | undefined>(undefined);
+
  const [isConfigInitialized, setConfigInitialized] = useState(false);

  const [userMessages, setUserMessages] = useState<string[]>([]);
@@ -363,6 +367,14 @@ export const AppContainer = (props: AppContainerProps) => {
    cancelAuthentication,
  } = useAuthCommand(settings, config, historyManager.addItem);

+  const { proQuotaRequest, handleProQuotaChoice } = useQuotaAndFallback({
+    config,
+    historyManager,
+    userTier,
+    setAuthState,
+    setModelSwitchedFromQuotaError,
+  });
+
  useInitializationAuthError(initializationResult.authError, onAuthError);

  // Sync user tier from config when authentication changes
@@ -740,7 +752,8 @@ export const AppContainer = (props: AppContainerProps) => {
    !initError &&
    !isProcessing &&
    (streamingState === StreamingState.Idle ||
-      streamingState === StreamingState.Responding);
+      streamingState === StreamingState.Responding) &&
+    !proQuotaRequest;

  const [controlsHeight, setControlsHeight] = useState(0);

@@ -1193,6 +1206,7 @@ export const AppContainer = (props: AppContainerProps) => {
    isAuthenticating ||
    isEditorDialogOpen ||
    showIdeRestartPrompt ||
+    !!proQuotaRequest ||
    isSubagentCreateDialogOpen ||
    isAgentsManagerDialogOpen ||
    isApprovalModeDialogOpen ||
@@ -1263,6 +1277,8 @@ export const AppContainer = (props: AppContainerProps) => {
      showWorkspaceMigrationDialog,
      workspaceExtensions,
      currentModel,
+      userTier,
+      proQuotaRequest,
      contextFileNames,
      errorCount,
      availableTerminalHeight,
@@ -1351,6 +1367,8 @@ export const AppContainer = (props: AppContainerProps) => {
      showAutoAcceptIndicator,
      showWorkspaceMigrationDialog,
      workspaceExtensions,
+      userTier,
+      proQuotaRequest,
      contextFileNames,
      errorCount,
      availableTerminalHeight,
@@ -1412,6 +1430,7 @@ export const AppContainer = (props: AppContainerProps) => {
      handleClearScreen,
      onWorkspaceMigrationDialogOpen,
      onWorkspaceMigrationDialogClose,
+      handleProQuotaChoice,
      // Vision switch dialog
      handleVisionSwitchSelect,
      // Welcome back dialog
@@ -1449,6 +1468,7 @@ export const AppContainer = (props: AppContainerProps) => {
      handleClearScreen,
      onWorkspaceMigrationDialogOpen,
      onWorkspaceMigrationDialogClose,
+      handleProQuotaChoice,
      handleVisionSwitchSelect,
      handleWelcomeBackSelection,
      handleWelcomeBackClose,
--- a/packages/cli/src/ui/auth/AuthDialog.test.tsx
+++ b/packages/cli/src/ui/auth/AuthDialog.test.tsx
@@ -168,7 +168,7 @@ describe('AuthDialog', () => {

    it('should not show the GEMINI_API_KEY message if QWEN_DEFAULT_AUTH_TYPE is set to something else', () => {
      process.env['GEMINI_API_KEY'] = 'foobar';
-      process.env['QWEN_DEFAULT_AUTH_TYPE'] = AuthType.USE_OPENAI;
+      process.env['QWEN_DEFAULT_AUTH_TYPE'] = AuthType.LOGIN_WITH_GOOGLE;

      const settings: LoadedSettings = new LoadedSettings(
        {
@@ -212,7 +212,7 @@ describe('AuthDialog', () => {

    it('should show the GEMINI_API_KEY message if QWEN_DEFAULT_AUTH_TYPE is set to use api key', () => {
      process.env['GEMINI_API_KEY'] = 'foobar';
-      process.env['QWEN_DEFAULT_AUTH_TYPE'] = AuthType.USE_OPENAI;
+      process.env['QWEN_DEFAULT_AUTH_TYPE'] = AuthType.USE_GEMINI;

      const settings: LoadedSettings = new LoadedSettings(
        {
@@ -504,12 +504,12 @@ describe('AuthDialog', () => {
      },
      {
        settings: {
-          security: { auth: { selectedType: AuthType.USE_OPENAI } },
+          security: { auth: { selectedType: AuthType.LOGIN_WITH_GOOGLE } },
          ui: { customThemes: {} },
          mcpServers: {},
        },
        originalSettings: {
-          security: { auth: { selectedType: AuthType.USE_OPENAI } },
+          security: { auth: { selectedType: AuthType.LOGIN_WITH_GOOGLE } },
          ui: { customThemes: {} },
          mcpServers: {},
        },
--- a/packages/cli/src/ui/auth/useAuth.ts
+++ b/packages/cli/src/ui/auth/useAuth.ts
@@ -225,24 +225,16 @@ export const useAuthCommand = (
    const defaultAuthType = process.env['QWEN_DEFAULT_AUTH_TYPE'];
    if (
      defaultAuthType &&
-      ![
-        AuthType.QWEN_OAUTH,
-        AuthType.USE_OPENAI,
-        AuthType.USE_GEMINI,
-        AuthType.USE_VERTEX_AI,
-      ].includes(defaultAuthType as AuthType)
+      ![AuthType.QWEN_OAUTH, AuthType.USE_OPENAI].includes(
+        defaultAuthType as AuthType,
+      )
    ) {
      onAuthError(
        t(
          'Invalid QWEN_DEFAULT_AUTH_TYPE value: "{{value}}". Valid values are: {{validValues}}',
          {
            value: defaultAuthType,
-            validValues: [
-              AuthType.QWEN_OAUTH,
-              AuthType.USE_OPENAI,
-              AuthType.USE_GEMINI,
-              AuthType.USE_VERTEX_AI,
-            ].join(', '),
+            validValues: [AuthType.QWEN_OAUTH, AuthType.USE_OPENAI].join(', '),
          },
        ),
      );
--- a/packages/cli/src/ui/commands/ideCommand.test.ts
+++ b/packages/cli/src/ui/commands/ideCommand.test.ts
@@ -15,6 +15,7 @@ vi.mock('@qwen-code/qwen-code-core', async (importOriginal) => {
  const original = await importOriginal<typeof core>();
  return {
    ...original,
+    getOauthClient: vi.fn(original.getOauthClient),
    getIdeInstaller: vi.fn(original.getIdeInstaller),
    IdeClient: {
      getInstance: vi.fn(),
--- a/packages/cli/src/ui/components/DialogManager.tsx
+++ b/packages/cli/src/ui/components/DialogManager.tsx
@@ -17,6 +17,7 @@ import { AuthDialog } from '../auth/AuthDialog.js';
 import { OpenAIKeyPrompt } from './OpenAIKeyPrompt.js';
 import { EditorSettingsDialog } from './EditorSettingsDialog.js';
 import { WorkspaceMigrationDialog } from './WorkspaceMigrationDialog.js';
+import { ProQuotaDialog } from './ProQuotaDialog.js';
 import { PermissionsModifyTrustDialog } from './PermissionsModifyTrustDialog.js';
 import { ModelDialog } from './ModelDialog.js';
 import { ApprovalModeDialog } from './ApprovalModeDialog.js';
@@ -86,6 +87,15 @@ export const DialogManager = ({
      />
    );
  }
+  if (uiState.proQuotaRequest) {
+    return (
+      <ProQuotaDialog
+        failedModel={uiState.proQuotaRequest.failedModel}
+        fallbackModel={uiState.proQuotaRequest.fallbackModel}
+        onChoice={uiActions.handleProQuotaChoice}
+      />
+    );
+  }
  if (uiState.shouldShowIdePrompt) {
    return (
      <IdeIntegrationNudge
--- a/packages/cli/src/ui/components/ProQuotaDialog.test.tsx
+++ b/packages/cli/src/ui/components/ProQuotaDialog.test.tsx
@@ -0,0 +1,91 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { render } from 'ink-testing-library';
+import { describe, it, expect, vi, beforeEach, type Mock } from 'vitest';
+import { ProQuotaDialog } from './ProQuotaDialog.js';
+import { RadioButtonSelect } from './shared/RadioButtonSelect.js';
+
+// Mock the child component to make it easier to test the parent
+vi.mock('./shared/RadioButtonSelect.js', () => ({
+  RadioButtonSelect: vi.fn(),
+}));
+
+describe('ProQuotaDialog', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('should render with correct title and options', () => {
+    const { lastFrame } = render(
+      <ProQuotaDialog
+        failedModel="gemini-2.5-pro"
+        fallbackModel="gemini-2.5-flash"
+        onChoice={() => {}}
+      />,
+    );
+
+    const output = lastFrame();
+    expect(output).toContain('Pro quota limit reached for gemini-2.5-pro.');
+
+    // Check that RadioButtonSelect was called with the correct items
+    expect(RadioButtonSelect).toHaveBeenCalledWith(
+      expect.objectContaining({
+        items: [
+          {
+            label: 'Change auth (executes the /auth command)',
+            value: 'auth',
+            key: 'auth',
+          },
+          {
+            label: `Continue with gemini-2.5-flash`,
+            value: 'continue',
+            key: 'continue',
+          },
+        ],
+      }),
+      undefined,
+    );
+  });
+
+  it('should call onChoice with "auth" when "Change auth" is selected', () => {
+    const mockOnChoice = vi.fn();
+    render(
+      <ProQuotaDialog
+        failedModel="gemini-2.5-pro"
+        fallbackModel="gemini-2.5-flash"
+        onChoice={mockOnChoice}
+      />,
+    );
+
+    // Get the onSelect function passed to RadioButtonSelect
+    const onSelect = (RadioButtonSelect as Mock).mock.calls[0][0].onSelect;
+
+    // Simulate the selection
+    onSelect('auth');
+
+    expect(mockOnChoice).toHaveBeenCalledWith('auth');
+  });
+
+  it('should call onChoice with "continue" when "Continue with flash" is selected', () => {
+    const mockOnChoice = vi.fn();
+    render(
+      <ProQuotaDialog
+        failedModel="gemini-2.5-pro"
+        fallbackModel="gemini-2.5-flash"
+        onChoice={mockOnChoice}
+      />,
+    );
+
+    // Get the onSelect function passed to RadioButtonSelect
+    const onSelect = (RadioButtonSelect as Mock).mock.calls[0][0].onSelect;
+
+    // Simulate the selection
+    onSelect('continue');
+
+    expect(mockOnChoice).toHaveBeenCalledWith('continue');
+  });
+});
--- a/packages/cli/src/ui/components/ProQuotaDialog.tsx
+++ b/packages/cli/src/ui/components/ProQuotaDialog.tsx
@@ -0,0 +1,55 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type React from 'react';
+import { Box, Text } from 'ink';
+import { RadioButtonSelect } from './shared/RadioButtonSelect.js';
+import { theme } from '../semantic-colors.js';
+import { t } from '../../i18n/index.js';
+
+interface ProQuotaDialogProps {
+  failedModel: string;
+  fallbackModel: string;
+  onChoice: (choice: 'auth' | 'continue') => void;
+}
+
+export function ProQuotaDialog({
+  failedModel,
+  fallbackModel,
+  onChoice,
+}: ProQuotaDialogProps): React.JSX.Element {
+  const items = [
+    {
+      label: t('Change auth (executes the /auth command)'),
+      value: 'auth' as const,
+      key: 'auth',
+    },
+    {
+      label: t('Continue with {{model}}', { model: fallbackModel }),
+      value: 'continue' as const,
+      key: 'continue',
+    },
+  ];
+
+  const handleSelect = (choice: 'auth' | 'continue') => {
+    onChoice(choice);
+  };
+
+  return (
+    <Box borderStyle="round" flexDirection="column" paddingX={1}>
+      <Text bold color={theme.status.warning}>
+        {t('Pro quota limit reached for {{model}}.', { model: failedModel })}
+      </Text>
+      <Box marginTop={1}>
+        <RadioButtonSelect
+          items={items}
+          initialIndex={1}
+          onSelect={handleSelect}
+        />
+      </Box>
+    </Box>
+  );
+}
--- a/packages/cli/src/ui/contexts/UIActionsContext.tsx
+++ b/packages/cli/src/ui/contexts/UIActionsContext.tsx
@@ -55,6 +55,7 @@ export interface UIActions {
  handleClearScreen: () => void;
  onWorkspaceMigrationDialogOpen: () => void;
  onWorkspaceMigrationDialogClose: () => void;
+  handleProQuotaChoice: (choice: 'auth' | 'continue') => void;
  // Vision switch dialog
  handleVisionSwitchSelect: (outcome: VisionSwitchOutcome) => void;
  // Welcome back dialog
--- a/packages/cli/src/ui/contexts/UIStateContext.tsx
+++ b/packages/cli/src/ui/contexts/UIStateContext.tsx
@@ -22,13 +22,21 @@ import type {
  AuthType,
  IdeContext,
  ApprovalMode,
+  UserTierId,
  IdeInfo,
+  FallbackIntent,
 } from '@qwen-code/qwen-code-core';
 import type { DOMElement } from 'ink';
 import type { SessionStatsState } from '../contexts/SessionContext.js';
 import type { ExtensionUpdateState } from '../state/extensions.js';
 import type { UpdateObject } from '../utils/updateCheck.js';

+export interface ProQuotaDialogRequest {
+  failedModel: string;
+  fallbackModel: string;
+  resolve: (intent: FallbackIntent) => void;
+}
+
 import { type UseHistoryManagerReturn } from '../hooks/useHistoryManager.js';
 import { type RestartReason } from '../hooks/useIdeTrustListener.js';

@@ -91,6 +99,8 @@ export interface UIState {
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  workspaceExtensions: any[]; // Extension[]
  // Quota-related state
+  userTier: UserTierId | undefined;
+  proQuotaRequest: ProQuotaDialogRequest | null;
  currentModel: string;
  contextFileNames: string[];
  errorCount: number;
--- a/packages/cli/src/ui/hooks/useGeminiStream.test.tsx
+++ b/packages/cli/src/ui/hooks/useGeminiStream.test.tsx
@@ -1323,7 +1323,7 @@ describe('useGeminiStream', () => {
    it('should call parseAndFormatApiError with the correct authType on stream initialization failure', async () => {
      // 1. Setup
      const mockError = new Error('Rate limit exceeded');
-      const mockAuthType = AuthType.USE_VERTEX_AI;
+      const mockAuthType = AuthType.LOGIN_WITH_GOOGLE;
      mockParseAndFormatApiError.mockClear();
      mockSendMessageStream.mockReturnValue(
        (async function* () {
@@ -1374,6 +1374,9 @@ describe('useGeminiStream', () => {
        expect(mockParseAndFormatApiError).toHaveBeenCalledWith(
          'Rate limit exceeded',
          mockAuthType,
+          undefined,
+          'gemini-2.5-pro',
+          'gemini-2.5-flash',
        );
      });
    });
@@ -2490,6 +2493,9 @@ describe('useGeminiStream', () => {
      expect(mockParseAndFormatApiError).toHaveBeenCalledWith(
        { message: 'Test error' },
        expect.any(String),
+        undefined,
+        'gemini-2.5-pro',
+        'gemini-2.5-flash',
      );
    });
  });
--- a/packages/cli/src/ui/hooks/useGeminiStream.ts
+++ b/packages/cli/src/ui/hooks/useGeminiStream.ts
@@ -26,6 +26,7 @@ import {
  GitService,
  UnauthorizedError,
  UserPromptEvent,
+  DEFAULT_GEMINI_FLASH_MODEL,
  logConversationFinishedEvent,
  ConversationFinishedEvent,
  ApprovalMode,
@@ -599,6 +600,9 @@ export const useGeminiStream = (
          text: parseAndFormatApiError(
            eventValue.error,
            config.getContentGeneratorConfig()?.authType,
+            undefined,
+            config.getModel(),
+            DEFAULT_GEMINI_FLASH_MODEL,
          ),
        },
        userMessageTimestamp,
@@ -650,9 +654,6 @@ export const useGeminiStream = (
          'Response stopped due to image safety violations.',
        [FinishReason.UNEXPECTED_TOOL_CALL]:
          'Response stopped due to unexpected tool call.',
-        [FinishReason.IMAGE_PROHIBITED_CONTENT]:
-          'Response stopped due to image prohibited content.',
-        [FinishReason.NO_IMAGE]: 'Response stopped due to no image.',
      };

      const message = finishReasonMessages[finishReason];
@@ -769,17 +770,11 @@ export const useGeminiStream = (
      for await (const event of stream) {
        switch (event.type) {
          case ServerGeminiEventType.Thought:
-            // If the thought has a subject, it's a discrete status update rather than
-            // a streamed textual thought, so we update the thought state directly.
-            if (event.value.subject) {
-              setThought(event.value);
-            } else {
-              thoughtBuffer = handleThoughtEvent(
-                event.value,
-                thoughtBuffer,
-                userMessageTimestamp,
-              );
-            }
+            thoughtBuffer = handleThoughtEvent(
+              event.value,
+              thoughtBuffer,
+              userMessageTimestamp,
+            );
            break;
          case ServerGeminiEventType.Content:
            geminiMessageBuffer = handleContentEvent(
@@ -850,7 +845,6 @@ export const useGeminiStream = (
      handleMaxSessionTurnsEvent,
      handleSessionTokenLimitExceededEvent,
      handleCitationEvent,
-      setThought,
    ],
  );

@@ -993,6 +987,9 @@ export const useGeminiStream = (
                text: parseAndFormatApiError(
                  getErrorMessage(error) || 'Unknown error',
                  config.getContentGeneratorConfig()?.authType,
+                  undefined,
+                  config.getModel(),
+                  DEFAULT_GEMINI_FLASH_MODEL,
                ),
              },
              userMessageTimestamp,
--- a/packages/cli/src/ui/hooks/useQuotaAndFallback.test.ts
+++ b/packages/cli/src/ui/hooks/useQuotaAndFallback.test.ts
@@ -0,0 +1,391 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  vi,
+  describe,
+  it,
+  expect,
+  beforeEach,
+  afterEach,
+  type Mock,
+} from 'vitest';
+import { act, renderHook } from '@testing-library/react';
+import {
+  type Config,
+  type FallbackModelHandler,
+  UserTierId,
+  AuthType,
+  isGenericQuotaExceededError,
+  isProQuotaExceededError,
+  makeFakeConfig,
+} from '@qwen-code/qwen-code-core';
+import { useQuotaAndFallback } from './useQuotaAndFallback.js';
+import type { UseHistoryManagerReturn } from './useHistoryManager.js';
+import { AuthState, MessageType } from '../types.js';
+
+// Mock the error checking functions from the core package to control test scenarios
+vi.mock('@qwen-code/qwen-code-core', async (importOriginal) => {
+  const original =
+    await importOriginal<typeof import('@qwen-code/qwen-code-core')>();
+  return {
+    ...original,
+    isGenericQuotaExceededError: vi.fn(),
+    isProQuotaExceededError: vi.fn(),
+  };
+});
+
+// Use a type alias for SpyInstance as it's not directly exported
+type SpyInstance = ReturnType<typeof vi.spyOn>;
+
+describe('useQuotaAndFallback', () => {
+  let mockConfig: Config;
+  let mockHistoryManager: UseHistoryManagerReturn;
+  let mockSetAuthState: Mock;
+  let mockSetModelSwitchedFromQuotaError: Mock;
+  let setFallbackHandlerSpy: SpyInstance;
+
+  const mockedIsGenericQuotaExceededError = isGenericQuotaExceededError as Mock;
+  const mockedIsProQuotaExceededError = isProQuotaExceededError as Mock;
+
+  beforeEach(() => {
+    mockConfig = makeFakeConfig();
+
+    // Spy on the method that requires the private field and mock its return.
+    // This is cleaner than modifying the config class for tests.
+    vi.spyOn(mockConfig, 'getContentGeneratorConfig').mockReturnValue({
+      model: 'test-model',
+      authType: AuthType.LOGIN_WITH_GOOGLE,
+    });
+
+    mockHistoryManager = {
+      addItem: vi.fn(),
+      history: [],
+      updateItem: vi.fn(),
+      clearItems: vi.fn(),
+      loadHistory: vi.fn(),
+    };
+    mockSetAuthState = vi.fn();
+    mockSetModelSwitchedFromQuotaError = vi.fn();
+
+    setFallbackHandlerSpy = vi.spyOn(mockConfig, 'setFallbackModelHandler');
+    vi.spyOn(mockConfig, 'setQuotaErrorOccurred');
+
+    mockedIsGenericQuotaExceededError.mockReturnValue(false);
+    mockedIsProQuotaExceededError.mockReturnValue(false);
+  });
+
+  afterEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('should register a fallback handler on initialization', () => {
+    renderHook(() =>
+      useQuotaAndFallback({
+        config: mockConfig,
+        historyManager: mockHistoryManager,
+        userTier: UserTierId.FREE,
+        setAuthState: mockSetAuthState,
+        setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+      }),
+    );
+
+    expect(setFallbackHandlerSpy).toHaveBeenCalledTimes(1);
+    expect(setFallbackHandlerSpy.mock.calls[0][0]).toBeInstanceOf(Function);
+  });
+
+  describe('Fallback Handler Logic', () => {
+    // Helper function to render the hook and extract the registered handler
+    const getRegisteredHandler = (
+      userTier: UserTierId = UserTierId.FREE,
+    ): FallbackModelHandler => {
+      renderHook(
+        (props) =>
+          useQuotaAndFallback({
+            config: mockConfig,
+            historyManager: mockHistoryManager,
+            userTier: props.userTier,
+            setAuthState: mockSetAuthState,
+            setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+          }),
+        { initialProps: { userTier } },
+      );
+      return setFallbackHandlerSpy.mock.calls[0][0] as FallbackModelHandler;
+    };
+
+    it('should return null and take no action if already in fallback mode', async () => {
+      vi.spyOn(mockConfig, 'isInFallbackMode').mockReturnValue(true);
+      const handler = getRegisteredHandler();
+      const result = await handler('gemini-pro', 'gemini-flash', new Error());
+
+      expect(result).toBeNull();
+      expect(mockHistoryManager.addItem).not.toHaveBeenCalled();
+    });
+
+    it('should return null and take no action if authType is not LOGIN_WITH_GOOGLE', async () => {
+      // Override the default mock from beforeEach for this specific test
+      vi.spyOn(mockConfig, 'getContentGeneratorConfig').mockReturnValue({
+        model: 'test-model',
+        authType: AuthType.USE_GEMINI,
+      });
+
+      const handler = getRegisteredHandler();
+      const result = await handler('gemini-pro', 'gemini-flash', new Error());
+
+      expect(result).toBeNull();
+      expect(mockHistoryManager.addItem).not.toHaveBeenCalled();
+    });
+
+    describe('Automatic Fallback Scenarios', () => {
+      const testCases = [
+        {
+          errorType: 'generic',
+          tier: UserTierId.FREE,
+          expectedMessageSnippets: [
+            'Automatically switching from model-A to model-B',
+            'upgrade to a Gemini Code Assist Standard or Enterprise plan',
+          ],
+        },
+        {
+          errorType: 'generic',
+          tier: UserTierId.STANDARD, // Paid tier
+          expectedMessageSnippets: [
+            'Automatically switching from model-A to model-B',
+            'switch to using a paid API key from AI Studio',
+          ],
+        },
+        {
+          errorType: 'other',
+          tier: UserTierId.FREE,
+          expectedMessageSnippets: [
+            'Automatically switching from model-A to model-B for faster responses',
+            'upgrade to a Gemini Code Assist Standard or Enterprise plan',
+          ],
+        },
+        {
+          errorType: 'other',
+          tier: UserTierId.LEGACY, // Paid tier
+          expectedMessageSnippets: [
+            'Automatically switching from model-A to model-B for faster responses',
+            'switch to using a paid API key from AI Studio',
+          ],
+        },
+      ];
+
+      for (const { errorType, tier, expectedMessageSnippets } of testCases) {
+        it(`should handle ${errorType} error for ${tier} tier correctly`, async () => {
+          mockedIsGenericQuotaExceededError.mockReturnValue(
+            errorType === 'generic',
+          );
+
+          const handler = getRegisteredHandler(tier);
+          const result = await handler(
+            'model-A',
+            'model-B',
+            new Error('quota exceeded'),
+          );
+
+          // Automatic fallbacks should return 'stop'
+          expect(result).toBe('stop');
+
+          expect(mockHistoryManager.addItem).toHaveBeenCalledWith(
+            expect.objectContaining({ type: MessageType.INFO }),
+            expect.any(Number),
+          );
+
+          const message = (mockHistoryManager.addItem as Mock).mock.calls[0][0]
+            .text;
+          for (const snippet of expectedMessageSnippets) {
+            expect(message).toContain(snippet);
+          }
+
+          expect(mockSetModelSwitchedFromQuotaError).toHaveBeenCalledWith(true);
+          expect(mockConfig.setQuotaErrorOccurred).toHaveBeenCalledWith(true);
+        });
+      }
+    });
+
+    describe('Interactive Fallback (Pro Quota Error)', () => {
+      beforeEach(() => {
+        mockedIsProQuotaExceededError.mockReturnValue(true);
+      });
+
+      it('should set an interactive request and wait for user choice', async () => {
+        const { result } = renderHook(() =>
+          useQuotaAndFallback({
+            config: mockConfig,
+            historyManager: mockHistoryManager,
+            userTier: UserTierId.FREE,
+            setAuthState: mockSetAuthState,
+            setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+          }),
+        );
+
+        const handler = setFallbackHandlerSpy.mock
+          .calls[0][0] as FallbackModelHandler;
+
+        // Call the handler but do not await it, to check the intermediate state
+        const promise = handler(
+          'gemini-pro',
+          'gemini-flash',
+          new Error('pro quota'),
+        );
+
+        await act(async () => {});
+
+        // The hook should now have a pending request for the UI to handle
+        expect(result.current.proQuotaRequest).not.toBeNull();
+        expect(result.current.proQuotaRequest?.failedModel).toBe('gemini-pro');
+
+        // Simulate the user choosing to continue with the fallback model
+        act(() => {
+          result.current.handleProQuotaChoice('continue');
+        });
+
+        // The original promise from the handler should now resolve
+        const intent = await promise;
+        expect(intent).toBe('retry');
+
+        // The pending request should be cleared from the state
+        expect(result.current.proQuotaRequest).toBeNull();
+      });
+
+      it('should handle race conditions by stopping subsequent requests', async () => {
+        const { result } = renderHook(() =>
+          useQuotaAndFallback({
+            config: mockConfig,
+            historyManager: mockHistoryManager,
+            userTier: UserTierId.FREE,
+            setAuthState: mockSetAuthState,
+            setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+          }),
+        );
+
+        const handler = setFallbackHandlerSpy.mock
+          .calls[0][0] as FallbackModelHandler;
+
+        const promise1 = handler(
+          'gemini-pro',
+          'gemini-flash',
+          new Error('pro quota 1'),
+        );
+        await act(async () => {});
+
+        const firstRequest = result.current.proQuotaRequest;
+        expect(firstRequest).not.toBeNull();
+
+        const result2 = await handler(
+          'gemini-pro',
+          'gemini-flash',
+          new Error('pro quota 2'),
+        );
+
+        // The lock should have stopped the second request
+        expect(result2).toBe('stop');
+        expect(result.current.proQuotaRequest).toBe(firstRequest);
+
+        act(() => {
+          result.current.handleProQuotaChoice('continue');
+        });
+
+        const intent1 = await promise1;
+        expect(intent1).toBe('retry');
+        expect(result.current.proQuotaRequest).toBeNull();
+      });
+    });
+  });
+
+  describe('handleProQuotaChoice', () => {
+    beforeEach(() => {
+      mockedIsProQuotaExceededError.mockReturnValue(true);
+    });
+
+    it('should do nothing if there is no pending pro quota request', () => {
+      const { result } = renderHook(() =>
+        useQuotaAndFallback({
+          config: mockConfig,
+          historyManager: mockHistoryManager,
+          userTier: UserTierId.FREE,
+          setAuthState: mockSetAuthState,
+          setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+        }),
+      );
+
+      act(() => {
+        result.current.handleProQuotaChoice('auth');
+      });
+
+      expect(mockSetAuthState).not.toHaveBeenCalled();
+      expect(mockHistoryManager.addItem).not.toHaveBeenCalled();
+    });
+
+    it('should resolve intent to "auth" and trigger auth state update', async () => {
+      const { result } = renderHook(() =>
+        useQuotaAndFallback({
+          config: mockConfig,
+          historyManager: mockHistoryManager,
+          userTier: UserTierId.FREE,
+          setAuthState: mockSetAuthState,
+          setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+        }),
+      );
+
+      const handler = setFallbackHandlerSpy.mock
+        .calls[0][0] as FallbackModelHandler;
+      const promise = handler(
+        'gemini-pro',
+        'gemini-flash',
+        new Error('pro quota'),
+      );
+      await act(async () => {}); // Allow state to update
+
+      act(() => {
+        result.current.handleProQuotaChoice('auth');
+      });
+
+      const intent = await promise;
+      expect(intent).toBe('auth');
+      expect(mockSetAuthState).toHaveBeenCalledWith(AuthState.Updating);
+      expect(result.current.proQuotaRequest).toBeNull();
+    });
+
+    it('should resolve intent to "retry" and add info message on continue', async () => {
+      const { result } = renderHook(() =>
+        useQuotaAndFallback({
+          config: mockConfig,
+          historyManager: mockHistoryManager,
+          userTier: UserTierId.FREE,
+          setAuthState: mockSetAuthState,
+          setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+        }),
+      );
+
+      const handler = setFallbackHandlerSpy.mock
+        .calls[0][0] as FallbackModelHandler;
+      // The first `addItem` call is for the initial quota error message
+      const promise = handler(
+        'gemini-pro',
+        'gemini-flash',
+        new Error('pro quota'),
+      );
+      await act(async () => {}); // Allow state to update
+
+      act(() => {
+        result.current.handleProQuotaChoice('continue');
+      });
+
+      const intent = await promise;
+      expect(intent).toBe('retry');
+      expect(result.current.proQuotaRequest).toBeNull();
+
+      // Check for the second "Switched to fallback model" message
+      expect(mockHistoryManager.addItem).toHaveBeenCalledTimes(2);
+      const lastCall = (mockHistoryManager.addItem as Mock).mock.calls[1][0];
+      expect(lastCall.type).toBe(MessageType.INFO);
+      expect(lastCall.text).toContain('Switched to fallback model.');
+    });
+  });
+});
--- a/packages/cli/src/ui/hooks/useQuotaAndFallback.ts
+++ b/packages/cli/src/ui/hooks/useQuotaAndFallback.ts
@@ -0,0 +1,175 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  AuthType,
+  type Config,
+  type FallbackModelHandler,
+  type FallbackIntent,
+  isGenericQuotaExceededError,
+  isProQuotaExceededError,
+  UserTierId,
+} from '@qwen-code/qwen-code-core';
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { type UseHistoryManagerReturn } from './useHistoryManager.js';
+import { AuthState, MessageType } from '../types.js';
+import { type ProQuotaDialogRequest } from '../contexts/UIStateContext.js';
+
+interface UseQuotaAndFallbackArgs {
+  config: Config;
+  historyManager: UseHistoryManagerReturn;
+  userTier: UserTierId | undefined;
+  setAuthState: (state: AuthState) => void;
+  setModelSwitchedFromQuotaError: (value: boolean) => void;
+}
+
+export function useQuotaAndFallback({
+  config,
+  historyManager,
+  userTier,
+  setAuthState,
+  setModelSwitchedFromQuotaError,
+}: UseQuotaAndFallbackArgs) {
+  const [proQuotaRequest, setProQuotaRequest] =
+    useState<ProQuotaDialogRequest | null>(null);
+  const isDialogPending = useRef(false);
+
+  // Set up Flash fallback handler
+  useEffect(() => {
+    const fallbackHandler: FallbackModelHandler = async (
+      failedModel,
+      fallbackModel,
+      error,
+    ): Promise<FallbackIntent | null> => {
+      if (config.isInFallbackMode()) {
+        return null;
+      }
+
+      // Fallbacks are currently only handled for OAuth users.
+      const contentGeneratorConfig = config.getContentGeneratorConfig();
+      if (
+        !contentGeneratorConfig ||
+        contentGeneratorConfig.authType !== AuthType.LOGIN_WITH_GOOGLE
+      ) {
+        return null;
+      }
+
+      // Use actual user tier if available; otherwise, default to FREE tier behavior (safe default)
+      const isPaidTier =
+        userTier === UserTierId.LEGACY || userTier === UserTierId.STANDARD;
+
+      let message: string;
+
+      if (error && isProQuotaExceededError(error)) {
+        // Pro Quota specific messages (Interactive)
+        if (isPaidTier) {
+          message = `⚡ You have reached your daily ${failedModel} quota limit.
+⚡ You can choose to authenticate with a paid API key or continue with the fallback model.
+⚡ To continue accessing the ${failedModel} model today, consider using /auth to switch to using a paid API key from AI Studio at https://aistudio.google.com/apikey`;
+        } else {
+          message = `⚡ You have reached your daily ${failedModel} quota limit.
+⚡ You can choose to authenticate with a paid API key or continue with the fallback model.
+⚡ To increase your limits, upgrade to a Gemini Code Assist Standard or Enterprise plan with higher limits at https://goo.gle/set-up-gemini-code-assist
+⚡ Or you can utilize a Gemini API Key. See: https://goo.gle/gemini-cli-docs-auth#gemini-api-key
+⚡ You can switch authentication methods by typing /auth`;
+        }
+      } else if (error && isGenericQuotaExceededError(error)) {
+        // Generic Quota (Automatic fallback)
+        const actionMessage = `⚡ You have reached your daily quota limit.\n⚡ Automatically switching from ${failedModel} to ${fallbackModel} for the remainder of this session.`;
+
+        if (isPaidTier) {
+          message = `${actionMessage}
+⚡ To continue accessing the ${failedModel} model today, consider using /auth to switch to using a paid API key from AI Studio at https://aistudio.google.com/apikey`;
+        } else {
+          message = `${actionMessage}
+⚡ To increase your limits, upgrade to a Gemini Code Assist Standard or Enterprise plan with higher limits at https://goo.gle/set-up-gemini-code-assist
+⚡ Or you can utilize a Gemini API Key. See: https://goo.gle/gemini-cli-docs-auth#gemini-api-key
+⚡ You can switch authentication methods by typing /auth`;
+        }
+      } else {
+        // Consecutive 429s or other errors (Automatic fallback)
+        const actionMessage = `⚡ Automatically switching from ${failedModel} to ${fallbackModel} for faster responses for the remainder of this session.`;
+
+        if (isPaidTier) {
+          message = `${actionMessage}
+⚡ Possible reasons for this are that you have received multiple consecutive capacity errors or you have reached your daily ${failedModel} quota limit
+⚡ To continue accessing the ${failedModel} model today, consider using /auth to switch to using a paid API key from AI Studio at https://aistudio.google.com/apikey`;
+        } else {
+          message = `${actionMessage}
+⚡ Possible reasons for this are that you have received multiple consecutive capacity errors or you have reached your daily ${failedModel} quota limit
+⚡ To increase your limits, upgrade to a Gemini Code Assist Standard or Enterprise plan with higher limits at https://goo.gle/set-up-gemini-code-assist
+⚡ Or you can utilize a Gemini API Key. See: https://goo.gle/gemini-cli-docs-auth#gemini-api-key
+⚡ You can switch authentication methods by typing /auth`;
+        }
+      }
+
+      // Add message to UI history
+      historyManager.addItem(
+        {
+          type: MessageType.INFO,
+          text: message,
+        },
+        Date.now(),
+      );
+
+      setModelSwitchedFromQuotaError(true);
+      config.setQuotaErrorOccurred(true);
+
+      // Interactive Fallback for Pro quota
+      if (error && isProQuotaExceededError(error)) {
+        if (isDialogPending.current) {
+          return 'stop'; // A dialog is already active, so just stop this request.
+        }
+        isDialogPending.current = true;
+
+        const intent: FallbackIntent = await new Promise<FallbackIntent>(
+          (resolve) => {
+            setProQuotaRequest({
+              failedModel,
+              fallbackModel,
+              resolve,
+            });
+          },
+        );
+
+        return intent;
+      }
+
+      return 'stop';
+    };
+
+    config.setFallbackModelHandler(fallbackHandler);
+  }, [config, historyManager, userTier, setModelSwitchedFromQuotaError]);
+
+  const handleProQuotaChoice = useCallback(
+    (choice: 'auth' | 'continue') => {
+      if (!proQuotaRequest) return;
+
+      const intent: FallbackIntent = choice === 'auth' ? 'auth' : 'retry';
+      proQuotaRequest.resolve(intent);
+      setProQuotaRequest(null);
+      isDialogPending.current = false; // Reset the flag here
+
+      if (choice === 'auth') {
+        setAuthState(AuthState.Updating);
+      } else {
+        historyManager.addItem(
+          {
+            type: MessageType.INFO,
+            text: 'Switched to fallback model. Tip: Press Ctrl+P (or Up Arrow) to recall your previous prompt and submit it again if you wish.',
+          },
+          Date.now(),
+        );
+      }
+    },
+    [proQuotaRequest, setAuthState, historyManager],
+  );
+
+  return {
+    proQuotaRequest,
+    handleProQuotaChoice,
+  };
+}
--- a/packages/cli/src/ui/hooks/useQwenAuth.test.ts
+++ b/packages/cli/src/ui/hooks/useQwenAuth.test.ts
@@ -411,7 +411,7 @@ describe('useQwenAuth', () => {
    expect(geminiResult.current.qwenAuthState.authStatus).toBe('idle');

    const { result: oauthResult } = renderHook(() =>
-      useQwenAuth(AuthType.USE_OPENAI, true),
+      useQwenAuth(AuthType.LOGIN_WITH_GOOGLE, true),
    );
    expect(oauthResult.current.qwenAuthState.authStatus).toBe('idle');
  });
--- a/packages/cli/src/ui/hooks/useToolScheduler.test.ts
+++ b/packages/cli/src/ui/hooks/useToolScheduler.test.ts
@@ -62,7 +62,7 @@ const mockConfig = {
  getAllowedTools: vi.fn(() => []),
  getContentGeneratorConfig: () => ({
    model: 'test-model',
-    authType: 'gemini-api-key',
+    authType: 'oauth-personal',
  }),
  getUseSmartEdit: () => false,
  getUseModelRouter: () => false,
--- a/packages/cli/src/validateNonInterActiveAuth.ts
+++ b/packages/cli/src/validateNonInterActiveAuth.ts
@@ -21,13 +21,6 @@ function getAuthTypeFromEnv(): AuthType | undefined {
    return AuthType.QWEN_OAUTH;
  }

-  if (process.env['GEMINI_API_KEY']) {
-    return AuthType.USE_GEMINI;
-  }
-  if (process.env['GOOGLE_API_KEY']) {
-    return AuthType.USE_VERTEX_AI;
-  }
-
  return undefined;
 }

--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@qwen-code/qwen-code-core",
-  "version": "0.6.0-preview.0",
+  "version": "0.6.0",
  "description": "Qwen Code Core",
  "repository": {
    "type": "git",
@@ -23,8 +23,8 @@
    "scripts/postinstall.js"
  ],
  "dependencies": {
-    "@google/genai": "1.30.0",
-    "@modelcontextprotocol/sdk": "^1.25.1",
+    "@google/genai": "1.16.0",
+    "@modelcontextprotocol/sdk": "^1.11.0",
    "@opentelemetry/api": "^1.9.0",
    "async-mutex": "^0.5.0",
    "@opentelemetry/exporter-logs-otlp-grpc": "^0.203.0",
@@ -34,6 +34,7 @@
    "@opentelemetry/exporter-trace-otlp-grpc": "^0.203.0",
    "@opentelemetry/exporter-trace-otlp-http": "^0.203.0",
    "@opentelemetry/instrumentation-http": "^0.203.0",
+    "@opentelemetry/resource-detector-gcp": "^0.40.0",
    "@opentelemetry/sdk-node": "^0.203.0",
    "@types/html-to-text": "^9.0.4",
    "@xterm/headless": "5.5.0",
@@ -47,7 +48,7 @@
    "fdir": "^6.4.6",
    "fzf": "^0.5.2",
    "glob": "^10.5.0",
-    "google-auth-library": "^10.5.0",
+    "google-auth-library": "^9.11.0",
    "html-to-text": "^9.0.5",
    "https-proxy-agent": "^7.0.6",
    "ignore": "^7.0.0",
--- a/packages/core/src/code_assist/codeAssist.ts
+++ b/packages/core/src/code_assist/codeAssist.ts
@@ -0,0 +1,54 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { ContentGenerator } from '../core/contentGenerator.js';
+import { AuthType } from '../core/contentGenerator.js';
+import { getOauthClient } from './oauth2.js';
+import { setupUser } from './setup.js';
+import type { HttpOptions } from './server.js';
+import { CodeAssistServer } from './server.js';
+import type { Config } from '../config/config.js';
+import { LoggingContentGenerator } from '../core/loggingContentGenerator.js';
+
+export async function createCodeAssistContentGenerator(
+  httpOptions: HttpOptions,
+  authType: AuthType,
+  config: Config,
+  sessionId?: string,
+): Promise<ContentGenerator> {
+  if (
+    authType === AuthType.LOGIN_WITH_GOOGLE ||
+    authType === AuthType.CLOUD_SHELL
+  ) {
+    const authClient = await getOauthClient(authType, config);
+    const userData = await setupUser(authClient);
+    return new CodeAssistServer(
+      authClient,
+      userData.projectId,
+      httpOptions,
+      sessionId,
+      userData.userTier,
+    );
+  }
+
+  throw new Error(`Unsupported authType: ${authType}`);
+}
+
+export function getCodeAssistServer(
+  config: Config,
+): CodeAssistServer | undefined {
+  let server = config.getContentGenerator();
+
+  // Unwrap LoggingContentGenerator if present
+  if (server instanceof LoggingContentGenerator) {
+    server = server.getWrapped();
+  }
+
+  if (!(server instanceof CodeAssistServer)) {
+    return undefined;
+  }
+  return server;
+}
--- a/packages/core/src/code_assist/converter.test.ts
+++ b/packages/core/src/code_assist/converter.test.ts
@@ -0,0 +1,456 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import type { CaGenerateContentResponse } from './converter.js';
+import {
+  toGenerateContentRequest,
+  fromGenerateContentResponse,
+  toContents,
+} from './converter.js';
+import type {
+  ContentListUnion,
+  GenerateContentParameters,
+} from '@google/genai';
+import {
+  GenerateContentResponse,
+  FinishReason,
+  BlockedReason,
+  type Part,
+} from '@google/genai';
+
+describe('converter', () => {
+  describe('toCodeAssistRequest', () => {
+    it('should convert a simple request with project', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: [{ role: 'user', parts: [{ text: 'Hello' }] }],
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        'my-project',
+        'my-session',
+      );
+      expect(codeAssistReq).toEqual({
+        model: 'gemini-pro',
+        project: 'my-project',
+        request: {
+          contents: [{ role: 'user', parts: [{ text: 'Hello' }] }],
+          systemInstruction: undefined,
+          cachedContent: undefined,
+          tools: undefined,
+          toolConfig: undefined,
+          labels: undefined,
+          safetySettings: undefined,
+          generationConfig: undefined,
+          session_id: 'my-session',
+        },
+        user_prompt_id: 'my-prompt',
+      });
+    });
+
+    it('should convert a request without a project', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: [{ role: 'user', parts: [{ text: 'Hello' }] }],
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        undefined,
+        'my-session',
+      );
+      expect(codeAssistReq).toEqual({
+        model: 'gemini-pro',
+        project: undefined,
+        request: {
+          contents: [{ role: 'user', parts: [{ text: 'Hello' }] }],
+          systemInstruction: undefined,
+          cachedContent: undefined,
+          tools: undefined,
+          toolConfig: undefined,
+          labels: undefined,
+          safetySettings: undefined,
+          generationConfig: undefined,
+          session_id: 'my-session',
+        },
+        user_prompt_id: 'my-prompt',
+      });
+    });
+
+    it('should convert a request with sessionId', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: [{ role: 'user', parts: [{ text: 'Hello' }] }],
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        'my-project',
+        'session-123',
+      );
+      expect(codeAssistReq).toEqual({
+        model: 'gemini-pro',
+        project: 'my-project',
+        request: {
+          contents: [{ role: 'user', parts: [{ text: 'Hello' }] }],
+          systemInstruction: undefined,
+          cachedContent: undefined,
+          tools: undefined,
+          toolConfig: undefined,
+          labels: undefined,
+          safetySettings: undefined,
+          generationConfig: undefined,
+          session_id: 'session-123',
+        },
+        user_prompt_id: 'my-prompt',
+      });
+    });
+
+    it('should handle string content', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: 'Hello',
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        'my-project',
+        'my-session',
+      );
+      expect(codeAssistReq.request.contents).toEqual([
+        { role: 'user', parts: [{ text: 'Hello' }] },
+      ]);
+    });
+
+    it('should handle Part[] content', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: [{ text: 'Hello' }, { text: 'World' }],
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        'my-project',
+        'my-session',
+      );
+      expect(codeAssistReq.request.contents).toEqual([
+        { role: 'user', parts: [{ text: 'Hello' }] },
+        { role: 'user', parts: [{ text: 'World' }] },
+      ]);
+    });
+
+    it('should handle system instructions', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: 'Hello',
+        config: {
+          systemInstruction: 'You are a helpful assistant.',
+        },
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        'my-project',
+        'my-session',
+      );
+      expect(codeAssistReq.request.systemInstruction).toEqual({
+        role: 'user',
+        parts: [{ text: 'You are a helpful assistant.' }],
+      });
+    });
+
+    it('should handle generation config', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: 'Hello',
+        config: {
+          temperature: 0.8,
+          topK: 40,
+        },
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        'my-project',
+        'my-session',
+      );
+      expect(codeAssistReq.request.generationConfig).toEqual({
+        temperature: 0.8,
+        topK: 40,
+      });
+    });
+
+    it('should handle all generation config fields', () => {
+      const genaiReq: GenerateContentParameters = {
+        model: 'gemini-pro',
+        contents: 'Hello',
+        config: {
+          temperature: 0.1,
+          topP: 0.2,
+          topK: 3,
+          candidateCount: 4,
+          maxOutputTokens: 5,
+          stopSequences: ['a'],
+          responseLogprobs: true,
+          logprobs: 6,
+          presencePenalty: 0.7,
+          frequencyPenalty: 0.8,
+          seed: 9,
+          responseMimeType: 'application/json',
+        },
+      };
+      const codeAssistReq = toGenerateContentRequest(
+        genaiReq,
+        'my-prompt',
+        'my-project',
+        'my-session',
+      );
+      expect(codeAssistReq.request.generationConfig).toEqual({
+        temperature: 0.1,
+        topP: 0.2,
+        topK: 3,
+        candidateCount: 4,
+        maxOutputTokens: 5,
+        stopSequences: ['a'],
+        responseLogprobs: true,
+        logprobs: 6,
+        presencePenalty: 0.7,
+        frequencyPenalty: 0.8,
+        seed: 9,
+        responseMimeType: 'application/json',
+      });
+    });
+  });
+
+  describe('fromCodeAssistResponse', () => {
+    it('should convert a simple response', () => {
+      const codeAssistRes: CaGenerateContentResponse = {
+        response: {
+          candidates: [
+            {
+              index: 0,
+              content: {
+                role: 'model',
+                parts: [{ text: 'Hi there!' }],
+              },
+              finishReason: FinishReason.STOP,
+              safetyRatings: [],
+            },
+          ],
+        },
+      };
+      const genaiRes = fromGenerateContentResponse(codeAssistRes);
+      expect(genaiRes).toBeInstanceOf(GenerateContentResponse);
+      expect(genaiRes.candidates).toEqual(codeAssistRes.response.candidates);
+    });
+
+    it('should handle prompt feedback and usage metadata', () => {
+      const codeAssistRes: CaGenerateContentResponse = {
+        response: {
+          candidates: [],
+          promptFeedback: {
+            blockReason: BlockedReason.SAFETY,
+            safetyRatings: [],
+          },
+          usageMetadata: {
+            promptTokenCount: 10,
+            candidatesTokenCount: 20,
+            totalTokenCount: 30,
+          },
+        },
+      };
+      const genaiRes = fromGenerateContentResponse(codeAssistRes);
+      expect(genaiRes.promptFeedback).toEqual(
+        codeAssistRes.response.promptFeedback,
+      );
+      expect(genaiRes.usageMetadata).toEqual(
+        codeAssistRes.response.usageMetadata,
+      );
+    });
+
+    it('should handle automatic function calling history', () => {
+      const codeAssistRes: CaGenerateContentResponse = {
+        response: {
+          candidates: [],
+          automaticFunctionCallingHistory: [
+            {
+              role: 'model',
+              parts: [
+                {
+                  functionCall: {
+                    name: 'test_function',
+                    args: {
+                      foo: 'bar',
+                    },
+                  },
+                },
+              ],
+            },
+          ],
+        },
+      };
+      const genaiRes = fromGenerateContentResponse(codeAssistRes);
+      expect(genaiRes.automaticFunctionCallingHistory).toEqual(
+        codeAssistRes.response.automaticFunctionCallingHistory,
+      );
+    });
+
+    it('should handle modelVersion', () => {
+      const codeAssistRes: CaGenerateContentResponse = {
+        response: {
+          candidates: [],
+          modelVersion: 'qwen3-coder-plus',
+        },
+      };
+      const genaiRes = fromGenerateContentResponse(codeAssistRes);
+      expect(genaiRes.modelVersion).toEqual('qwen3-coder-plus');
+    });
+  });
+
+  describe('toContents', () => {
+    it('should handle Content', () => {
+      const content: ContentListUnion = {
+        role: 'user',
+        parts: [{ text: 'hello' }],
+      };
+      expect(toContents(content)).toEqual([
+        { role: 'user', parts: [{ text: 'hello' }] },
+      ]);
+    });
+
+    it('should handle array of Contents', () => {
+      const contents: ContentListUnion = [
+        { role: 'user', parts: [{ text: 'hello' }] },
+        { role: 'model', parts: [{ text: 'hi' }] },
+      ];
+      expect(toContents(contents)).toEqual([
+        { role: 'user', parts: [{ text: 'hello' }] },
+        { role: 'model', parts: [{ text: 'hi' }] },
+      ]);
+    });
+
+    it('should handle Part', () => {
+      const part: ContentListUnion = { text: 'a part' };
+      expect(toContents(part)).toEqual([
+        { role: 'user', parts: [{ text: 'a part' }] },
+      ]);
+    });
+
+    it('should handle array of Parts', () => {
+      const parts = [{ text: 'part 1' }, 'part 2'];
+      expect(toContents(parts)).toEqual([
+        { role: 'user', parts: [{ text: 'part 1' }] },
+        { role: 'user', parts: [{ text: 'part 2' }] },
+      ]);
+    });
+
+    it('should handle string', () => {
+      const str: ContentListUnion = 'a string';
+      expect(toContents(str)).toEqual([
+        { role: 'user', parts: [{ text: 'a string' }] },
+      ]);
+    });
+
+    it('should handle array of strings', () => {
+      const strings: ContentListUnion = ['string 1', 'string 2'];
+      expect(toContents(strings)).toEqual([
+        { role: 'user', parts: [{ text: 'string 1' }] },
+        { role: 'user', parts: [{ text: 'string 2' }] },
+      ]);
+    });
+
+    it('should convert thought parts to text parts for API compatibility', () => {
+      const contentWithThought: ContentListUnion = {
+        role: 'model',
+        parts: [
+          { text: 'regular text' },
+          { thought: 'thinking about the problem' } as Part & {
+            thought: string;
+          },
+          { text: 'more text' },
+        ],
+      };
+      expect(toContents(contentWithThought)).toEqual([
+        {
+          role: 'model',
+          parts: [
+            { text: 'regular text' },
+            { text: '[Thought: thinking about the problem]' },
+            { text: 'more text' },
+          ],
+        },
+      ]);
+    });
+
+    it('should combine text and thought for text parts with thoughts', () => {
+      const contentWithTextAndThought: ContentListUnion = {
+        role: 'model',
+        parts: [
+          {
+            text: 'Here is my response',
+            thought: 'I need to be careful here',
+          } as Part & { thought: string },
+        ],
+      };
+      expect(toContents(contentWithTextAndThought)).toEqual([
+        {
+          role: 'model',
+          parts: [
+            {
+              text: 'Here is my response\n[Thought: I need to be careful here]',
+            },
+          ],
+        },
+      ]);
+    });
+
+    it('should preserve non-thought properties while removing thought', () => {
+      const contentWithComplexPart: ContentListUnion = {
+        role: 'model',
+        parts: [
+          {
+            functionCall: { name: 'calculate', args: { x: 5, y: 10 } },
+            thought: 'Performing calculation',
+          } as Part & { thought: string },
+        ],
+      };
+      expect(toContents(contentWithComplexPart)).toEqual([
+        {
+          role: 'model',
+          parts: [
+            {
+              functionCall: { name: 'calculate', args: { x: 5, y: 10 } },
+            },
+          ],
+        },
+      ]);
+    });
+
+    it('should convert invalid text content to valid text part with thought', () => {
+      const contentWithInvalidText: ContentListUnion = {
+        role: 'model',
+        parts: [
+          {
+            text: 123, // Invalid - should be string
+            thought: 'Processing number',
+          } as Part & { thought: string; text: number },
+        ],
+      };
+      expect(toContents(contentWithInvalidText)).toEqual([
+        {
+          role: 'model',
+          parts: [
+            {
+              text: '123\n[Thought: Processing number]',
+            },
+          ],
+        },
+      ]);
+    });
+  });
+});
--- a/packages/core/src/code_assist/converter.ts
+++ b/packages/core/src/code_assist/converter.ts
@@ -0,0 +1,285 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type {
+  Content,
+  ContentListUnion,
+  ContentUnion,
+  GenerateContentConfig,
+  GenerateContentParameters,
+  CountTokensParameters,
+  CountTokensResponse,
+  GenerationConfigRoutingConfig,
+  MediaResolution,
+  Candidate,
+  ModelSelectionConfig,
+  GenerateContentResponsePromptFeedback,
+  GenerateContentResponseUsageMetadata,
+  Part,
+  SafetySetting,
+  PartUnion,
+  SpeechConfigUnion,
+  ThinkingConfig,
+  ToolListUnion,
+  ToolConfig,
+} from '@google/genai';
+import { GenerateContentResponse } from '@google/genai';
+
+export interface CAGenerateContentRequest {
+  model: string;
+  project?: string;
+  user_prompt_id?: string;
+  request: VertexGenerateContentRequest;
+}
+
+interface VertexGenerateContentRequest {
+  contents: Content[];
+  systemInstruction?: Content;
+  cachedContent?: string;
+  tools?: ToolListUnion;
+  toolConfig?: ToolConfig;
+  labels?: Record<string, string>;
+  safetySettings?: SafetySetting[];
+  generationConfig?: VertexGenerationConfig;
+  session_id?: string;
+}
+
+interface VertexGenerationConfig {
+  temperature?: number;
+  topP?: number;
+  topK?: number;
+  candidateCount?: number;
+  maxOutputTokens?: number;
+  stopSequences?: string[];
+  responseLogprobs?: boolean;
+  logprobs?: number;
+  presencePenalty?: number;
+  frequencyPenalty?: number;
+  seed?: number;
+  responseMimeType?: string;
+  responseJsonSchema?: unknown;
+  responseSchema?: unknown;
+  routingConfig?: GenerationConfigRoutingConfig;
+  modelSelectionConfig?: ModelSelectionConfig;
+  responseModalities?: string[];
+  mediaResolution?: MediaResolution;
+  speechConfig?: SpeechConfigUnion;
+  audioTimestamp?: boolean;
+  thinkingConfig?: ThinkingConfig;
+}
+
+export interface CaGenerateContentResponse {
+  response: VertexGenerateContentResponse;
+}
+
+interface VertexGenerateContentResponse {
+  candidates: Candidate[];
+  automaticFunctionCallingHistory?: Content[];
+  promptFeedback?: GenerateContentResponsePromptFeedback;
+  usageMetadata?: GenerateContentResponseUsageMetadata;
+  modelVersion?: string;
+}
+
+export interface CaCountTokenRequest {
+  request: VertexCountTokenRequest;
+}
+
+interface VertexCountTokenRequest {
+  model: string;
+  contents: Content[];
+}
+
+export interface CaCountTokenResponse {
+  totalTokens: number;
+}
+
+export function toCountTokenRequest(
+  req: CountTokensParameters,
+): CaCountTokenRequest {
+  return {
+    request: {
+      model: 'models/' + req.model,
+      contents: toContents(req.contents),
+    },
+  };
+}
+
+export function fromCountTokenResponse(
+  res: CaCountTokenResponse,
+): CountTokensResponse {
+  return {
+    totalTokens: res.totalTokens,
+  };
+}
+
+export function toGenerateContentRequest(
+  req: GenerateContentParameters,
+  userPromptId: string,
+  project?: string,
+  sessionId?: string,
+): CAGenerateContentRequest {
+  return {
+    model: req.model,
+    project,
+    user_prompt_id: userPromptId,
+    request: toVertexGenerateContentRequest(req, sessionId),
+  };
+}
+
+export function fromGenerateContentResponse(
+  res: CaGenerateContentResponse,
+): GenerateContentResponse {
+  const inres = res.response;
+  const out = new GenerateContentResponse();
+  out.candidates = inres.candidates;
+  out.automaticFunctionCallingHistory = inres.automaticFunctionCallingHistory;
+  out.promptFeedback = inres.promptFeedback;
+  out.usageMetadata = inres.usageMetadata;
+  out.modelVersion = inres.modelVersion;
+  return out;
+}
+
+function toVertexGenerateContentRequest(
+  req: GenerateContentParameters,
+  sessionId?: string,
+): VertexGenerateContentRequest {
+  return {
+    contents: toContents(req.contents),
+    systemInstruction: maybeToContent(req.config?.systemInstruction),
+    cachedContent: req.config?.cachedContent,
+    tools: req.config?.tools,
+    toolConfig: req.config?.toolConfig,
+    labels: req.config?.labels,
+    safetySettings: req.config?.safetySettings,
+    generationConfig: toVertexGenerationConfig(req.config),
+    session_id: sessionId,
+  };
+}
+
+export function toContents(contents: ContentListUnion): Content[] {
+  if (Array.isArray(contents)) {
+    // it's a Content[] or a PartsUnion[]
+    return contents.map(toContent);
+  }
+  // it's a Content or a PartsUnion
+  return [toContent(contents)];
+}
+
+function maybeToContent(content?: ContentUnion): Content | undefined {
+  if (!content) {
+    return undefined;
+  }
+  return toContent(content);
+}
+
+function toContent(content: ContentUnion): Content {
+  if (Array.isArray(content)) {
+    // it's a PartsUnion[]
+    return {
+      role: 'user',
+      parts: toParts(content),
+    };
+  }
+  if (typeof content === 'string') {
+    // it's a string
+    return {
+      role: 'user',
+      parts: [{ text: content }],
+    };
+  }
+  if ('parts' in content) {
+    // it's a Content - process parts to handle thought filtering
+    return {
+      ...content,
+      parts: content.parts
+        ? toParts(content.parts.filter((p) => p != null))
+        : [],
+    };
+  }
+  // it's a Part
+  return {
+    role: 'user',
+    parts: [toPart(content as Part)],
+  };
+}
+
+export function toParts(parts: PartUnion[]): Part[] {
+  return parts.map(toPart);
+}
+
+function toPart(part: PartUnion): Part {
+  if (typeof part === 'string') {
+    // it's a string
+    return { text: part };
+  }
+
+  // Handle thought parts for CountToken API compatibility
+  // The CountToken API expects parts to have certain required "oneof" fields initialized,
+  // but thought parts don't conform to this schema and cause API failures
+  if ('thought' in part && part.thought) {
+    const thoughtText = `[Thought: ${part.thought}]`;
+
+    const newPart = { ...part };
+    delete (newPart as Record<string, unknown>)['thought'];
+
+    const hasApiContent =
+      'functionCall' in newPart ||
+      'functionResponse' in newPart ||
+      'inlineData' in newPart ||
+      'fileData' in newPart;
+
+    if (hasApiContent) {
+      // It's a functionCall or other non-text part. Just strip the thought.
+      return newPart;
+    }
+
+    // If no other valid API content, this must be a text part.
+    // Combine existing text (if any) with the thought, preserving other properties.
+    const text = (newPart as { text?: unknown }).text;
+    const existingText = text ? String(text) : '';
+    const combinedText = existingText
+      ? `${existingText}\n${thoughtText}`
+      : thoughtText;
+
+    return {
+      ...newPart,
+      text: combinedText,
+    };
+  }
+
+  return part;
+}
+
+function toVertexGenerationConfig(
+  config?: GenerateContentConfig,
+): VertexGenerationConfig | undefined {
+  if (!config) {
+    return undefined;
+  }
+  return {
+    temperature: config.temperature,
+    topP: config.topP,
+    topK: config.topK,
+    candidateCount: config.candidateCount,
+    maxOutputTokens: config.maxOutputTokens,
+    stopSequences: config.stopSequences,
+    responseLogprobs: config.responseLogprobs,
+    logprobs: config.logprobs,
+    presencePenalty: config.presencePenalty,
+    frequencyPenalty: config.frequencyPenalty,
+    seed: config.seed,
+    responseMimeType: config.responseMimeType,
+    responseSchema: config.responseSchema,
+    responseJsonSchema: config.responseJsonSchema,
+    routingConfig: config.routingConfig,
+    modelSelectionConfig: config.modelSelectionConfig,
+    responseModalities: config.responseModalities,
+    mediaResolution: config.mediaResolution,
+    speechConfig: config.speechConfig,
+    audioTimestamp: config.audioTimestamp,
+    thinkingConfig: config.thinkingConfig,
+  };
+}
--- a/packages/core/src/code_assist/oauth-credential-storage.test.ts
+++ b/packages/core/src/code_assist/oauth-credential-storage.test.ts
@@ -0,0 +1,217 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { type Credentials } from 'google-auth-library';
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { OAuthCredentialStorage } from './oauth-credential-storage.js';
+import type { OAuthCredentials } from '../mcp/token-storage/types.js';
+
+import * as path from 'node:path';
+import * as os from 'node:os';
+import { promises as fs } from 'node:fs';
+
+// Mock external dependencies
+const mockHybridTokenStorage = vi.hoisted(() => ({
+  getCredentials: vi.fn(),
+  setCredentials: vi.fn(),
+  deleteCredentials: vi.fn(),
+}));
+vi.mock('../mcp/token-storage/hybrid-token-storage.js', () => ({
+  HybridTokenStorage: vi.fn(() => mockHybridTokenStorage),
+}));
+vi.mock('node:fs', () => ({
+  promises: {
+    readFile: vi.fn(),
+    rm: vi.fn(),
+  },
+}));
+vi.mock('node:os');
+vi.mock('node:path');
+
+describe('OAuthCredentialStorage', () => {
+  const mockCredentials: Credentials = {
+    access_token: 'mock_access_token',
+    refresh_token: 'mock_refresh_token',
+    expiry_date: Date.now() + 3600 * 1000,
+    token_type: 'Bearer',
+    scope: 'email profile',
+  };
+
+  const mockMcpCredentials: OAuthCredentials = {
+    serverName: 'main-account',
+    token: {
+      accessToken: 'mock_access_token',
+      refreshToken: 'mock_refresh_token',
+      tokenType: 'Bearer',
+      scope: 'email profile',
+      expiresAt: mockCredentials.expiry_date!,
+    },
+    updatedAt: expect.any(Number),
+  };
+
+  const oldFilePath = '/mock/home/.qwen/oauth.json';
+
+  beforeEach(() => {
+    vi.spyOn(mockHybridTokenStorage, 'getCredentials').mockResolvedValue(null);
+    vi.spyOn(mockHybridTokenStorage, 'setCredentials').mockResolvedValue(
+      undefined,
+    );
+    vi.spyOn(mockHybridTokenStorage, 'deleteCredentials').mockResolvedValue(
+      undefined,
+    );
+
+    vi.spyOn(fs, 'readFile').mockRejectedValue(new Error('File not found'));
+    vi.spyOn(fs, 'rm').mockResolvedValue(undefined);
+
+    vi.spyOn(os, 'homedir').mockReturnValue('/mock/home');
+    vi.spyOn(path, 'join').mockReturnValue(oldFilePath);
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  describe('loadCredentials', () => {
+    it('should load credentials from HybridTokenStorage if available', async () => {
+      vi.spyOn(mockHybridTokenStorage, 'getCredentials').mockResolvedValue(
+        mockMcpCredentials,
+      );
+
+      const result = await OAuthCredentialStorage.loadCredentials();
+
+      expect(mockHybridTokenStorage.getCredentials).toHaveBeenCalledWith(
+        'main-account',
+      );
+      expect(result).toEqual(mockCredentials);
+    });
+
+    it('should fallback to migrateFromFileStorage if no credentials in HybridTokenStorage', async () => {
+      vi.spyOn(mockHybridTokenStorage, 'getCredentials').mockResolvedValue(
+        null,
+      );
+      vi.spyOn(fs, 'readFile').mockResolvedValue(
+        JSON.stringify(mockCredentials),
+      );
+
+      const result = await OAuthCredentialStorage.loadCredentials();
+
+      expect(mockHybridTokenStorage.getCredentials).toHaveBeenCalledWith(
+        'main-account',
+      );
+      expect(fs.readFile).toHaveBeenCalledWith(oldFilePath, 'utf-8');
+      expect(mockHybridTokenStorage.setCredentials).toHaveBeenCalled(); // Verify credentials were saved
+      expect(fs.rm).toHaveBeenCalledWith(oldFilePath, { force: true }); // Verify old file was removed
+      expect(result).toEqual(mockCredentials);
+    });
+
+    it('should return null if no credentials found and no old file to migrate', async () => {
+      vi.spyOn(fs, 'readFile').mockRejectedValue({
+        message: 'File not found',
+        code: 'ENOENT',
+      });
+
+      const result = await OAuthCredentialStorage.loadCredentials();
+
+      expect(result).toBeNull();
+    });
+
+    it('should throw an error if loading fails', async () => {
+      vi.spyOn(mockHybridTokenStorage, 'getCredentials').mockRejectedValue(
+        new Error('Loading error'),
+      );
+
+      await expect(OAuthCredentialStorage.loadCredentials()).rejects.toThrow(
+        'Failed to load OAuth credentials',
+      );
+    });
+
+    it('should throw an error if read file fails', async () => {
+      vi.spyOn(mockHybridTokenStorage, 'getCredentials').mockResolvedValue(
+        null,
+      );
+      vi.spyOn(fs, 'readFile').mockRejectedValue(
+        new Error('Permission denied'),
+      );
+
+      await expect(OAuthCredentialStorage.loadCredentials()).rejects.toThrow(
+        'Failed to load OAuth credentials',
+      );
+    });
+
+    it('should not throw error if migration file removal failed', async () => {
+      vi.spyOn(mockHybridTokenStorage, 'getCredentials').mockResolvedValue(
+        null,
+      );
+      vi.spyOn(fs, 'readFile').mockResolvedValue(
+        JSON.stringify(mockCredentials),
+      );
+      vi.spyOn(OAuthCredentialStorage, 'saveCredentials').mockResolvedValue(
+        undefined,
+      );
+      vi.spyOn(fs, 'rm').mockRejectedValue(new Error('Deletion failed'));
+
+      const result = await OAuthCredentialStorage.loadCredentials();
+
+      expect(result).toEqual(mockCredentials);
+    });
+  });
+
+  describe('saveCredentials', () => {
+    it('should save credentials to HybridTokenStorage', async () => {
+      await OAuthCredentialStorage.saveCredentials(mockCredentials);
+
+      expect(mockHybridTokenStorage.setCredentials).toHaveBeenCalledWith(
+        mockMcpCredentials,
+      );
+    });
+
+    it('should throw an error if access_token is missing', async () => {
+      const invalidCredentials: Credentials = {
+        ...mockCredentials,
+        access_token: undefined,
+      };
+      await expect(
+        OAuthCredentialStorage.saveCredentials(invalidCredentials),
+      ).rejects.toThrow(
+        'Attempted to save credentials without an access token.',
+      );
+    });
+  });
+
+  describe('clearCredentials', () => {
+    it('should delete credentials from HybridTokenStorage', async () => {
+      await OAuthCredentialStorage.clearCredentials();
+
+      expect(mockHybridTokenStorage.deleteCredentials).toHaveBeenCalledWith(
+        'main-account',
+      );
+    });
+
+    it('should attempt to remove the old file-based storage', async () => {
+      await OAuthCredentialStorage.clearCredentials();
+
+      expect(fs.rm).toHaveBeenCalledWith(oldFilePath, { force: true });
+    });
+
+    it('should not throw an error if deleting old file fails', async () => {
+      vi.spyOn(fs, 'rm').mockRejectedValue(new Error('File deletion failed'));
+
+      await expect(
+        OAuthCredentialStorage.clearCredentials(),
+      ).resolves.toBeUndefined();
+    });
+
+    it('should throw an error if clearing from HybridTokenStorage fails', async () => {
+      vi.spyOn(mockHybridTokenStorage, 'deleteCredentials').mockRejectedValue(
+        new Error('Deletion error'),
+      );
+
+      await expect(OAuthCredentialStorage.clearCredentials()).rejects.toThrow(
+        'Failed to clear OAuth credentials',
+      );
+    });
+  });
+});
--- a/packages/core/src/code_assist/oauth-credential-storage.ts
+++ b/packages/core/src/code_assist/oauth-credential-storage.ts
@@ -0,0 +1,130 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { type Credentials } from 'google-auth-library';
+import { HybridTokenStorage } from '../mcp/token-storage/hybrid-token-storage.js';
+import { OAUTH_FILE } from '../config/storage.js';
+import type { OAuthCredentials } from '../mcp/token-storage/types.js';
+import * as path from 'node:path';
+import * as os from 'node:os';
+import { promises as fs } from 'node:fs';
+
+const QWEN_DIR = '.qwen';
+const KEYCHAIN_SERVICE_NAME = 'qwen-code-oauth';
+const MAIN_ACCOUNT_KEY = 'main-account';
+
+export class OAuthCredentialStorage {
+  private static storage: HybridTokenStorage = new HybridTokenStorage(
+    KEYCHAIN_SERVICE_NAME,
+  );
+
+  /**
+   * Load cached OAuth credentials
+   */
+  static async loadCredentials(): Promise<Credentials | null> {
+    try {
+      const credentials = await this.storage.getCredentials(MAIN_ACCOUNT_KEY);
+
+      if (credentials?.token) {
+        const { accessToken, refreshToken, expiresAt, tokenType, scope } =
+          credentials.token;
+        // Convert from OAuthCredentials format to Google Credentials format
+        const googleCreds: Credentials = {
+          access_token: accessToken,
+          refresh_token: refreshToken || undefined,
+          token_type: tokenType || undefined,
+          scope: scope || undefined,
+        };
+
+        if (expiresAt) {
+          googleCreds.expiry_date = expiresAt;
+        }
+
+        return googleCreds;
+      }
+
+      // Fallback: Try to migrate from old file-based storage
+      return await this.migrateFromFileStorage();
+    } catch (error: unknown) {
+      console.error(error);
+      throw new Error('Failed to load OAuth credentials');
+    }
+  }
+
+  /**
+   * Save OAuth credentials
+   */
+  static async saveCredentials(credentials: Credentials): Promise<void> {
+    if (!credentials.access_token) {
+      throw new Error('Attempted to save credentials without an access token.');
+    }
+
+    // Convert Google Credentials to OAuthCredentials format
+    const mcpCredentials: OAuthCredentials = {
+      serverName: MAIN_ACCOUNT_KEY,
+      token: {
+        accessToken: credentials.access_token,
+        refreshToken: credentials.refresh_token || undefined,
+        tokenType: credentials.token_type || 'Bearer',
+        scope: credentials.scope || undefined,
+        expiresAt: credentials.expiry_date || undefined,
+      },
+      updatedAt: Date.now(),
+    };
+
+    await this.storage.setCredentials(mcpCredentials);
+  }
+
+  /**
+   * Clear cached OAuth credentials
+   */
+  static async clearCredentials(): Promise<void> {
+    try {
+      await this.storage.deleteCredentials(MAIN_ACCOUNT_KEY);
+
+      // Also try to remove the old file if it exists
+      const oldFilePath = path.join(os.homedir(), QWEN_DIR, OAUTH_FILE);
+      await fs.rm(oldFilePath, { force: true }).catch(() => {});
+    } catch (error: unknown) {
+      console.error(error);
+      throw new Error('Failed to clear OAuth credentials');
+    }
+  }
+
+  /**
+   * Migrate credentials from old file-based storage to keychain
+   */
+  private static async migrateFromFileStorage(): Promise<Credentials | null> {
+    const oldFilePath = path.join(os.homedir(), QWEN_DIR, OAUTH_FILE);
+
+    let credsJson: string;
+    try {
+      credsJson = await fs.readFile(oldFilePath, 'utf-8');
+    } catch (error: unknown) {
+      if (
+        typeof error === 'object' &&
+        error !== null &&
+        'code' in error &&
+        error.code === 'ENOENT'
+      ) {
+        // File doesn't exist, so no migration.
+        return null;
+      }
+      // Other read errors should propagate.
+      throw error;
+    }
+
+    const credentials = JSON.parse(credsJson) as Credentials;
+
+    // Save to new storage
+    await this.saveCredentials(credentials);
+
+    // Remove old file after successful migration
+    await fs.rm(oldFilePath, { force: true }).catch(() => {});
+
+    return credentials;
+  }
+}
--- a/packages/core/src/code_assist/oauth2.test.ts
+++ b/packages/core/src/code_assist/oauth2.test.ts
--- a/packages/core/src/code_assist/oauth2.ts
+++ b/packages/core/src/code_assist/oauth2.ts
@@ -0,0 +1,563 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { Credentials } from 'google-auth-library';
+import {
+  CodeChallengeMethod,
+  Compute,
+  OAuth2Client,
+} from 'google-auth-library';
+import crypto from 'node:crypto';
+import { promises as fs } from 'node:fs';
+import * as http from 'node:http';
+import * as net from 'node:net';
+import path from 'node:path';
+import readline from 'node:readline';
+import url from 'node:url';
+import open from 'open';
+import type { Config } from '../config/config.js';
+import { Storage } from '../config/storage.js';
+import { AuthType } from '../core/contentGenerator.js';
+import { FatalAuthenticationError, getErrorMessage } from '../utils/errors.js';
+import { UserAccountManager } from '../utils/userAccountManager.js';
+import { OAuthCredentialStorage } from './oauth-credential-storage.js';
+import { FORCE_ENCRYPTED_FILE_ENV_VAR } from '../mcp/token-storage/index.js';
+
+const userAccountManager = new UserAccountManager();
+
+//  OAuth Client ID used to initiate OAuth2Client class.
+const OAUTH_CLIENT_ID =
+  '681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com';
+
+// OAuth Secret value used to initiate OAuth2Client class.
+// Note: It's ok to save this in git because this is an installed application
+// as described here: https://developers.google.com/identity/protocols/oauth2#installed
+// "The process results in a client ID and, in some cases, a client secret,
+// which you embed in the source code of your application. (In this context,
+// the client secret is obviously not treated as a secret.)"
+const OAUTH_CLIENT_SECRET = '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';
+
+// OAuth Scopes for Cloud Code authorization.
+const OAUTH_SCOPE = [
+  'https://www.googleapis.com/auth/cloud-platform',
+  'https://www.googleapis.com/auth/userinfo.email',
+  'https://www.googleapis.com/auth/userinfo.profile',
+];
+
+const HTTP_REDIRECT = 301;
+const SIGN_IN_SUCCESS_URL =
+  'https://developers.google.com/gemini-code-assist/auth_success_gemini';
+const SIGN_IN_FAILURE_URL =
+  'https://developers.google.com/gemini-code-assist/auth_failure_gemini';
+
+/**
+ * An Authentication URL for updating the credentials of a Oauth2Client
+ * as well as a promise that will resolve when the credentials have
+ * been refreshed (or which throws error when refreshing credentials failed).
+ */
+export interface OauthWebLogin {
+  authUrl: string;
+  loginCompletePromise: Promise<void>;
+}
+
+const oauthClientPromises = new Map<AuthType, Promise<OAuth2Client>>();
+
+function getUseEncryptedStorageFlag() {
+  return process.env[FORCE_ENCRYPTED_FILE_ENV_VAR] === 'true';
+}
+
+async function initOauthClient(
+  authType: AuthType,
+  config: Config,
+): Promise<OAuth2Client> {
+  const client = new OAuth2Client({
+    clientId: OAUTH_CLIENT_ID,
+    clientSecret: OAUTH_CLIENT_SECRET,
+    transporterOptions: {
+      proxy: config.getProxy(),
+    },
+  });
+  const useEncryptedStorage = getUseEncryptedStorageFlag();
+
+  if (
+    process.env['GOOGLE_GENAI_USE_GCA'] &&
+    process.env['GOOGLE_CLOUD_ACCESS_TOKEN']
+  ) {
+    client.setCredentials({
+      access_token: process.env['GOOGLE_CLOUD_ACCESS_TOKEN'],
+    });
+    await fetchAndCacheUserInfo(client);
+    return client;
+  }
+
+  client.on('tokens', async (tokens: Credentials) => {
+    if (useEncryptedStorage) {
+      await OAuthCredentialStorage.saveCredentials(tokens);
+    } else {
+      await cacheCredentials(tokens);
+    }
+  });
+
+  // If there are cached creds on disk, they always take precedence
+  if (await loadCachedCredentials(client)) {
+    // Found valid cached credentials.
+    // Check if we need to retrieve Google Account ID or Email
+    if (!userAccountManager.getCachedGoogleAccount()) {
+      try {
+        await fetchAndCacheUserInfo(client);
+      } catch (error) {
+        // Non-fatal, continue with existing auth.
+        console.warn('Failed to fetch user info:', getErrorMessage(error));
+      }
+    }
+    console.log('Loaded cached credentials.');
+    return client;
+  }
+
+  // In Google Cloud Shell, we can use Application Default Credentials (ADC)
+  // provided via its metadata server to authenticate non-interactively using
+  // the identity of the user logged into Cloud Shell.
+  if (authType === AuthType.CLOUD_SHELL) {
+    try {
+      console.log("Attempting to authenticate via Cloud Shell VM's ADC.");
+      const computeClient = new Compute({
+        // We can leave this empty, since the metadata server will provide
+        // the service account email.
+      });
+      await computeClient.getAccessToken();
+      console.log('Authentication successful.');
+
+      // Do not cache creds in this case; note that Compute client will handle its own refresh
+      return computeClient;
+    } catch (e) {
+      throw new Error(
+        `Could not authenticate using Cloud Shell credentials. Please select a different authentication method or ensure you are in a properly configured environment. Error: ${getErrorMessage(
+          e,
+        )}`,
+      );
+    }
+  }
+
+  if (config.isBrowserLaunchSuppressed()) {
+    let success = false;
+    const maxRetries = 2;
+    for (let i = 0; !success && i < maxRetries; i++) {
+      success = await authWithUserCode(client);
+      if (!success) {
+        console.error(
+          '\nFailed to authenticate with user code.',
+          i === maxRetries - 1 ? '' : 'Retrying...\n',
+        );
+      }
+    }
+    if (!success) {
+      throw new FatalAuthenticationError(
+        'Failed to authenticate with user code.',
+      );
+    }
+  } else {
+    const webLogin = await authWithWeb(client);
+
+    console.log(
+      `\n\nCode Assist login required.\n` +
+        `Attempting to open authentication page in your browser.\n` +
+        `Otherwise navigate to:\n\n${webLogin.authUrl}\n\n`,
+    );
+    try {
+      // Attempt to open the authentication URL in the default browser.
+      // We do not use the `wait` option here because the main script's execution
+      // is already paused by `loginCompletePromise`, which awaits the server callback.
+      const childProcess = await open(webLogin.authUrl);
+
+      // IMPORTANT: Attach an error handler to the returned child process.
+      // Without this, if `open` fails to spawn a process (e.g., `xdg-open` is not found
+      // in a minimal Docker container), it will emit an unhandled 'error' event,
+      // causing the entire Node.js process to crash.
+      childProcess.on('error', (error) => {
+        console.error(
+          'Failed to open browser automatically. Please try running again with NO_BROWSER=true set.',
+        );
+        console.error('Browser error details:', getErrorMessage(error));
+      });
+    } catch (err) {
+      console.error(
+        'An unexpected error occurred while trying to open the browser:',
+        getErrorMessage(err),
+        '\nThis might be due to browser compatibility issues or system configuration.',
+        '\nPlease try running again with NO_BROWSER=true set for manual authentication.',
+      );
+      throw new FatalAuthenticationError(
+        `Failed to open browser: ${getErrorMessage(err)}`,
+      );
+    }
+    console.log('Waiting for authentication...');
+
+    // Add timeout to prevent infinite waiting when browser tab gets stuck
+    const authTimeout = 5 * 60 * 1000; // 5 minutes timeout
+    const timeoutPromise = new Promise<never>((_, reject) => {
+      setTimeout(() => {
+        reject(
+          new FatalAuthenticationError(
+            'Authentication timed out after 5 minutes. The browser tab may have gotten stuck in a loading state. ' +
+              'Please try again or use NO_BROWSER=true for manual authentication.',
+          ),
+        );
+      }, authTimeout);
+    });
+
+    await Promise.race([webLogin.loginCompletePromise, timeoutPromise]);
+  }
+
+  return client;
+}
+
+export async function getOauthClient(
+  authType: AuthType,
+  config: Config,
+): Promise<OAuth2Client> {
+  if (!oauthClientPromises.has(authType)) {
+    oauthClientPromises.set(authType, initOauthClient(authType, config));
+  }
+  return oauthClientPromises.get(authType)!;
+}
+
+async function authWithUserCode(client: OAuth2Client): Promise<boolean> {
+  const redirectUri = 'https://codeassist.google.com/authcode';
+  const codeVerifier = await client.generateCodeVerifierAsync();
+  const state = crypto.randomBytes(32).toString('hex');
+  const authUrl: string = client.generateAuthUrl({
+    redirect_uri: redirectUri,
+    access_type: 'offline',
+    scope: OAUTH_SCOPE,
+    code_challenge_method: CodeChallengeMethod.S256,
+    code_challenge: codeVerifier.codeChallenge,
+    state,
+  });
+  console.log('Please visit the following URL to authorize the application:');
+  console.log('');
+  console.log(authUrl);
+  console.log('');
+
+  const code = await new Promise<string>((resolve) => {
+    const rl = readline.createInterface({
+      input: process.stdin,
+      output: process.stdout,
+    });
+    rl.question('Enter the authorization code: ', (code) => {
+      rl.close();
+      resolve(code.trim());
+    });
+  });
+
+  if (!code) {
+    console.error('Authorization code is required.');
+    return false;
+  }
+
+  try {
+    const { tokens } = await client.getToken({
+      code,
+      codeVerifier: codeVerifier.codeVerifier,
+      redirect_uri: redirectUri,
+    });
+    client.setCredentials(tokens);
+  } catch (error) {
+    console.error(
+      'Failed to authenticate with authorization code:',
+      getErrorMessage(error),
+    );
+    return false;
+  }
+  return true;
+}
+
+async function authWithWeb(client: OAuth2Client): Promise<OauthWebLogin> {
+  const port = await getAvailablePort();
+  // The hostname used for the HTTP server binding (e.g., '0.0.0.0' in Docker).
+  const host = process.env['OAUTH_CALLBACK_HOST'] || 'localhost';
+  // The `redirectUri` sent to Google's authorization server MUST use a loopback IP literal
+  // (i.e., 'localhost' or '127.0.0.1'). This is a strict security policy for credentials of
+  // type 'Desktop app' or 'Web application' (when using loopback flow) to mitigate
+  // authorization code interception attacks.
+  const redirectUri = `http://localhost:${port}/oauth2callback`;
+  const state = crypto.randomBytes(32).toString('hex');
+  const authUrl = client.generateAuthUrl({
+    redirect_uri: redirectUri,
+    access_type: 'offline',
+    scope: OAUTH_SCOPE,
+    state,
+  });
+
+  const loginCompletePromise = new Promise<void>((resolve, reject) => {
+    const server = http.createServer(async (req, res) => {
+      try {
+        if (req.url!.indexOf('/oauth2callback') === -1) {
+          res.writeHead(HTTP_REDIRECT, { Location: SIGN_IN_FAILURE_URL });
+          res.end();
+          reject(
+            new FatalAuthenticationError(
+              'OAuth callback not received. Unexpected request: ' + req.url,
+            ),
+          );
+        }
+        // acquire the code from the querystring, and close the web server.
+        const qs = new url.URL(req.url!, 'http://localhost:3000').searchParams;
+        if (qs.get('error')) {
+          res.writeHead(HTTP_REDIRECT, { Location: SIGN_IN_FAILURE_URL });
+          res.end();
+
+          const errorCode = qs.get('error');
+          const errorDescription =
+            qs.get('error_description') || 'No additional details provided';
+          reject(
+            new FatalAuthenticationError(
+              `Google OAuth error: ${errorCode}. ${errorDescription}`,
+            ),
+          );
+        } else if (qs.get('state') !== state) {
+          res.end('State mismatch. Possible CSRF attack');
+
+          reject(
+            new FatalAuthenticationError(
+              'OAuth state mismatch. Possible CSRF attack or browser session issue.',
+            ),
+          );
+        } else if (qs.get('code')) {
+          try {
+            const { tokens } = await client.getToken({
+              code: qs.get('code')!,
+              redirect_uri: redirectUri,
+            });
+            client.setCredentials(tokens);
+
+            // Retrieve and cache Google Account ID during authentication
+            try {
+              await fetchAndCacheUserInfo(client);
+            } catch (error) {
+              console.warn(
+                'Failed to retrieve Google Account ID during authentication:',
+                getErrorMessage(error),
+              );
+              // Don't fail the auth flow if Google Account ID retrieval fails
+            }
+
+            res.writeHead(HTTP_REDIRECT, { Location: SIGN_IN_SUCCESS_URL });
+            res.end();
+            resolve();
+          } catch (error) {
+            res.writeHead(HTTP_REDIRECT, { Location: SIGN_IN_FAILURE_URL });
+            res.end();
+            reject(
+              new FatalAuthenticationError(
+                `Failed to exchange authorization code for tokens: ${getErrorMessage(error)}`,
+              ),
+            );
+          }
+        } else {
+          reject(
+            new FatalAuthenticationError(
+              'No authorization code received from Google OAuth. Please try authenticating again.',
+            ),
+          );
+        }
+      } catch (e) {
+        // Provide more specific error message for unexpected errors during OAuth flow
+        if (e instanceof FatalAuthenticationError) {
+          reject(e);
+        } else {
+          reject(
+            new FatalAuthenticationError(
+              `Unexpected error during OAuth authentication: ${getErrorMessage(e)}`,
+            ),
+          );
+        }
+      } finally {
+        server.close();
+      }
+    });
+
+    server.listen(port, host, () => {
+      // Server started successfully
+    });
+
+    server.on('error', (err) => {
+      reject(
+        new FatalAuthenticationError(
+          `OAuth callback server error: ${getErrorMessage(err)}`,
+        ),
+      );
+    });
+  });
+
+  return {
+    authUrl,
+    loginCompletePromise,
+  };
+}
+
+export function getAvailablePort(): Promise<number> {
+  return new Promise((resolve, reject) => {
+    let port = 0;
+    try {
+      const portStr = process.env['OAUTH_CALLBACK_PORT'];
+      if (portStr) {
+        port = parseInt(portStr, 10);
+        if (isNaN(port) || port <= 0 || port > 65535) {
+          return reject(
+            new Error(`Invalid value for OAUTH_CALLBACK_PORT: "${portStr}"`),
+          );
+        }
+        return resolve(port);
+      }
+      const server = net.createServer();
+      server.listen(0, () => {
+        const address = server.address()! as net.AddressInfo;
+        port = address.port;
+      });
+      server.on('listening', () => {
+        server.close();
+        server.unref();
+      });
+      server.on('error', (e) => reject(e));
+      server.on('close', () => resolve(port));
+    } catch (e) {
+      reject(e);
+    }
+  });
+}
+
+async function loadCachedCredentials(client: OAuth2Client): Promise<boolean> {
+  const useEncryptedStorage = getUseEncryptedStorageFlag();
+  if (useEncryptedStorage) {
+    const credentials = await OAuthCredentialStorage.loadCredentials();
+    if (credentials) {
+      client.setCredentials(credentials);
+      return true;
+    }
+    return false;
+  }
+
+  const pathsToTry = [
+    Storage.getOAuthCredsPath(),
+    process.env['GOOGLE_APPLICATION_CREDENTIALS'],
+  ].filter((p): p is string => !!p);
+
+  for (const keyFile of pathsToTry) {
+    try {
+      const creds = await fs.readFile(keyFile, 'utf-8');
+      client.setCredentials(JSON.parse(creds));
+
+      // This will verify locally that the credentials look good.
+      const { token } = await client.getAccessToken();
+      if (!token) {
+        continue;
+      }
+
+      // This will check with the server to see if it hasn't been revoked.
+      await client.getTokenInfo(token);
+
+      return true;
+    } catch (error) {
+      // Log specific error for debugging, but continue trying other paths
+      console.debug(
+        `Failed to load credentials from ${keyFile}:`,
+        getErrorMessage(error),
+      );
+    }
+  }
+
+  return false;
+}
+
+async function cacheCredentials(credentials: Credentials) {
+  const filePath = Storage.getOAuthCredsPath();
+  await fs.mkdir(path.dirname(filePath), { recursive: true });
+
+  const credString = JSON.stringify(credentials, null, 2);
+  await fs.writeFile(filePath, credString, { mode: 0o600 });
+  try {
+    await fs.chmod(filePath, 0o600);
+  } catch {
+    /* empty */
+  }
+}
+
+export function clearOauthClientCache() {
+  oauthClientPromises.clear();
+}
+
+export async function clearCachedCredentialFile() {
+  try {
+    const useEncryptedStorage = getUseEncryptedStorageFlag();
+    if (useEncryptedStorage) {
+      await OAuthCredentialStorage.clearCredentials();
+    } else {
+      await fs.rm(Storage.getOAuthCredsPath(), { force: true });
+    }
+    // Clear the Google Account ID cache when credentials are cleared
+    await userAccountManager.clearCachedGoogleAccount();
+    // Clear the in-memory OAuth client cache to force re-authentication
+    clearOauthClientCache();
+
+    /**
+     * Also clear Qwen SharedTokenManager cache and credentials file to prevent stale credentials
+     * when switching between auth types
+     * TODO: We do not depend on code_assist, we'll have to build an independent auth-cleaning procedure.
+     */
+    try {
+      const { SharedTokenManager } = await import(
+        '../qwen/sharedTokenManager.js'
+      );
+      const { clearQwenCredentials } = await import('../qwen/qwenOAuth2.js');
+
+      const sharedManager = SharedTokenManager.getInstance();
+      sharedManager.clearCache();
+
+      await clearQwenCredentials();
+    } catch (qwenError) {
+      console.debug('Could not clear Qwen credentials:', qwenError);
+    }
+  } catch (e) {
+    console.error('Failed to clear cached credentials:', e);
+  }
+}
+
+async function fetchAndCacheUserInfo(client: OAuth2Client): Promise<void> {
+  try {
+    const { token } = await client.getAccessToken();
+    if (!token) {
+      return;
+    }
+
+    const response = await fetch(
+      'https://www.googleapis.com/oauth2/v2/userinfo',
+      {
+        headers: {
+          Authorization: `Bearer ${token}`,
+        },
+      },
+    );
+
+    if (!response.ok) {
+      console.error(
+        'Failed to fetch user info:',
+        response.status,
+        response.statusText,
+      );
+      return;
+    }
+
+    const userInfo = await response.json();
+    await userAccountManager.cacheGoogleAccount(userInfo.email);
+  } catch (error) {
+    console.error('Error retrieving user info:', error);
+  }
+}
+
+// Helper to ensure test isolation
+export function resetOauthClientForTesting() {
+  oauthClientPromises.clear();
+}
--- a/packages/core/src/code_assist/server.test.ts
+++ b/packages/core/src/code_assist/server.test.ts
@@ -0,0 +1,255 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { beforeEach, describe, it, expect, vi } from 'vitest';
+import { CodeAssistServer } from './server.js';
+import { OAuth2Client } from 'google-auth-library';
+import { UserTierId } from './types.js';
+
+vi.mock('google-auth-library');
+
+describe('CodeAssistServer', () => {
+  beforeEach(() => {
+    vi.resetAllMocks();
+  });
+
+  it('should be able to be constructed', () => {
+    const auth = new OAuth2Client();
+    const server = new CodeAssistServer(
+      auth,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    expect(server).toBeInstanceOf(CodeAssistServer);
+  });
+
+  it('should call the generateContent endpoint', async () => {
+    const client = new OAuth2Client();
+    const server = new CodeAssistServer(
+      client,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    const mockResponse = {
+      response: {
+        candidates: [
+          {
+            index: 0,
+            content: {
+              role: 'model',
+              parts: [{ text: 'response' }],
+            },
+            finishReason: 'STOP',
+            safetyRatings: [],
+          },
+        ],
+      },
+    };
+    vi.spyOn(server, 'requestPost').mockResolvedValue(mockResponse);
+
+    const response = await server.generateContent(
+      {
+        model: 'test-model',
+        contents: [{ role: 'user', parts: [{ text: 'request' }] }],
+      },
+      'user-prompt-id',
+    );
+
+    expect(server.requestPost).toHaveBeenCalledWith(
+      'generateContent',
+      expect.any(Object),
+      undefined,
+    );
+    expect(response.candidates?.[0]?.content?.parts?.[0]?.text).toBe(
+      'response',
+    );
+  });
+
+  it('should call the generateContentStream endpoint', async () => {
+    const client = new OAuth2Client();
+    const server = new CodeAssistServer(
+      client,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    const mockResponse = (async function* () {
+      yield {
+        response: {
+          candidates: [
+            {
+              index: 0,
+              content: {
+                role: 'model',
+                parts: [{ text: 'response' }],
+              },
+              finishReason: 'STOP',
+              safetyRatings: [],
+            },
+          ],
+        },
+      };
+    })();
+    vi.spyOn(server, 'requestStreamingPost').mockResolvedValue(mockResponse);
+
+    const stream = await server.generateContentStream(
+      {
+        model: 'test-model',
+        contents: [{ role: 'user', parts: [{ text: 'request' }] }],
+      },
+      'user-prompt-id',
+    );
+
+    for await (const res of stream) {
+      expect(server.requestStreamingPost).toHaveBeenCalledWith(
+        'streamGenerateContent',
+        expect.any(Object),
+        undefined,
+      );
+      expect(res.candidates?.[0]?.content?.parts?.[0]?.text).toBe('response');
+    }
+  });
+
+  it('should call the onboardUser endpoint', async () => {
+    const client = new OAuth2Client();
+    const server = new CodeAssistServer(
+      client,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    const mockResponse = {
+      name: 'operations/123',
+      done: true,
+    };
+    vi.spyOn(server, 'requestPost').mockResolvedValue(mockResponse);
+
+    const response = await server.onboardUser({
+      tierId: 'test-tier',
+      cloudaicompanionProject: 'test-project',
+      metadata: {},
+    });
+
+    expect(server.requestPost).toHaveBeenCalledWith(
+      'onboardUser',
+      expect.any(Object),
+    );
+    expect(response.name).toBe('operations/123');
+  });
+
+  it('should call the loadCodeAssist endpoint', async () => {
+    const client = new OAuth2Client();
+    const server = new CodeAssistServer(
+      client,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    const mockResponse = {
+      currentTier: {
+        id: UserTierId.FREE,
+        name: 'Free',
+        description: 'free tier',
+      },
+      allowedTiers: [],
+      ineligibleTiers: [],
+      cloudaicompanionProject: 'projects/test',
+    };
+    vi.spyOn(server, 'requestPost').mockResolvedValue(mockResponse);
+
+    const response = await server.loadCodeAssist({
+      metadata: {},
+    });
+
+    expect(server.requestPost).toHaveBeenCalledWith(
+      'loadCodeAssist',
+      expect.any(Object),
+    );
+    expect(response).toEqual(mockResponse);
+  });
+
+  it('should return 0 for countTokens', async () => {
+    const client = new OAuth2Client();
+    const server = new CodeAssistServer(
+      client,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    const mockResponse = {
+      totalTokens: 100,
+    };
+    vi.spyOn(server, 'requestPost').mockResolvedValue(mockResponse);
+
+    const response = await server.countTokens({
+      model: 'test-model',
+      contents: [{ role: 'user', parts: [{ text: 'request' }] }],
+    });
+    expect(response.totalTokens).toBe(100);
+  });
+
+  it('should throw an error for embedContent', async () => {
+    const client = new OAuth2Client();
+    const server = new CodeAssistServer(
+      client,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    await expect(
+      server.embedContent({
+        model: 'test-model',
+        contents: [{ role: 'user', parts: [{ text: 'request' }] }],
+      }),
+    ).rejects.toThrow();
+  });
+
+  it('should handle VPC-SC errors when calling loadCodeAssist', async () => {
+    const client = new OAuth2Client();
+    const server = new CodeAssistServer(
+      client,
+      'test-project',
+      {},
+      'test-session',
+      UserTierId.FREE,
+    );
+    const mockVpcScError = {
+      response: {
+        data: {
+          error: {
+            details: [
+              {
+                reason: 'SECURITY_POLICY_VIOLATED',
+              },
+            ],
+          },
+        },
+      },
+    };
+    vi.spyOn(server, 'requestPost').mockRejectedValue(mockVpcScError);
+
+    const response = await server.loadCodeAssist({
+      metadata: {},
+    });
+
+    expect(server.requestPost).toHaveBeenCalledWith(
+      'loadCodeAssist',
+      expect.any(Object),
+    );
+    expect(response).toEqual({
+      currentTier: { id: UserTierId.STANDARD },
+    });
+  });
+});
--- a/packages/core/src/code_assist/server.ts
+++ b/packages/core/src/code_assist/server.ts
@@ -0,0 +1,253 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { OAuth2Client } from 'google-auth-library';
+import type {
+  CodeAssistGlobalUserSettingResponse,
+  GoogleRpcResponse,
+  LoadCodeAssistRequest,
+  LoadCodeAssistResponse,
+  LongRunningOperationResponse,
+  OnboardUserRequest,
+  SetCodeAssistGlobalUserSettingRequest,
+} from './types.js';
+import type {
+  CountTokensParameters,
+  CountTokensResponse,
+  EmbedContentParameters,
+  EmbedContentResponse,
+  GenerateContentParameters,
+  GenerateContentResponse,
+} from '@google/genai';
+import * as readline from 'node:readline';
+import type { ContentGenerator } from '../core/contentGenerator.js';
+import { UserTierId } from './types.js';
+import type {
+  CaCountTokenResponse,
+  CaGenerateContentResponse,
+} from './converter.js';
+import {
+  fromCountTokenResponse,
+  fromGenerateContentResponse,
+  toCountTokenRequest,
+  toGenerateContentRequest,
+} from './converter.js';
+
+/** HTTP options to be used in each of the requests. */
+export interface HttpOptions {
+  /** Additional HTTP headers to be sent with the request. */
+  headers?: Record<string, string>;
+}
+
+export const CODE_ASSIST_ENDPOINT = 'https://localhost:0'; // Disable Google Code Assist API Request
+export const CODE_ASSIST_API_VERSION = 'v1internal';
+
+export class CodeAssistServer implements ContentGenerator {
+  constructor(
+    readonly client: OAuth2Client,
+    readonly projectId?: string,
+    readonly httpOptions: HttpOptions = {},
+    readonly sessionId?: string,
+    readonly userTier?: UserTierId,
+  ) {}
+
+  async generateContentStream(
+    req: GenerateContentParameters,
+    userPromptId: string,
+  ): Promise<AsyncGenerator<GenerateContentResponse>> {
+    const resps = await this.requestStreamingPost<CaGenerateContentResponse>(
+      'streamGenerateContent',
+      toGenerateContentRequest(
+        req,
+        userPromptId,
+        this.projectId,
+        this.sessionId,
+      ),
+      req.config?.abortSignal,
+    );
+    return (async function* (): AsyncGenerator<GenerateContentResponse> {
+      for await (const resp of resps) {
+        yield fromGenerateContentResponse(resp);
+      }
+    })();
+  }
+
+  async generateContent(
+    req: GenerateContentParameters,
+    userPromptId: string,
+  ): Promise<GenerateContentResponse> {
+    const resp = await this.requestPost<CaGenerateContentResponse>(
+      'generateContent',
+      toGenerateContentRequest(
+        req,
+        userPromptId,
+        this.projectId,
+        this.sessionId,
+      ),
+      req.config?.abortSignal,
+    );
+    return fromGenerateContentResponse(resp);
+  }
+
+  async onboardUser(
+    req: OnboardUserRequest,
+  ): Promise<LongRunningOperationResponse> {
+    return await this.requestPost<LongRunningOperationResponse>(
+      'onboardUser',
+      req,
+    );
+  }
+
+  async loadCodeAssist(
+    req: LoadCodeAssistRequest,
+  ): Promise<LoadCodeAssistResponse> {
+    try {
+      return await this.requestPost<LoadCodeAssistResponse>(
+        'loadCodeAssist',
+        req,
+      );
+    } catch (e) {
+      if (isVpcScAffectedUser(e)) {
+        return {
+          currentTier: { id: UserTierId.STANDARD },
+        };
+      } else {
+        throw e;
+      }
+    }
+  }
+
+  async getCodeAssistGlobalUserSetting(): Promise<CodeAssistGlobalUserSettingResponse> {
+    return await this.requestGet<CodeAssistGlobalUserSettingResponse>(
+      'getCodeAssistGlobalUserSetting',
+    );
+  }
+
+  async setCodeAssistGlobalUserSetting(
+    req: SetCodeAssistGlobalUserSettingRequest,
+  ): Promise<CodeAssistGlobalUserSettingResponse> {
+    return await this.requestPost<CodeAssistGlobalUserSettingResponse>(
+      'setCodeAssistGlobalUserSetting',
+      req,
+    );
+  }
+
+  async countTokens(req: CountTokensParameters): Promise<CountTokensResponse> {
+    const resp = await this.requestPost<CaCountTokenResponse>(
+      'countTokens',
+      toCountTokenRequest(req),
+    );
+    return fromCountTokenResponse(resp);
+  }
+
+  async embedContent(
+    _req: EmbedContentParameters,
+  ): Promise<EmbedContentResponse> {
+    throw Error();
+  }
+
+  async requestPost<T>(
+    method: string,
+    req: object,
+    signal?: AbortSignal,
+  ): Promise<T> {
+    const res = await this.client.request({
+      url: this.getMethodUrl(method),
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        ...this.httpOptions.headers,
+      },
+      responseType: 'json',
+      body: JSON.stringify(req),
+      signal,
+    });
+    return res.data as T;
+  }
+
+  async requestGet<T>(method: string, signal?: AbortSignal): Promise<T> {
+    const res = await this.client.request({
+      url: this.getMethodUrl(method),
+      method: 'GET',
+      headers: {
+        'Content-Type': 'application/json',
+        ...this.httpOptions.headers,
+      },
+      responseType: 'json',
+      signal,
+    });
+    return res.data as T;
+  }
+
+  async requestStreamingPost<T>(
+    method: string,
+    req: object,
+    signal?: AbortSignal,
+  ): Promise<AsyncGenerator<T>> {
+    const res = await this.client.request({
+      url: this.getMethodUrl(method),
+      method: 'POST',
+      params: {
+        alt: 'sse',
+      },
+      headers: {
+        'Content-Type': 'application/json',
+        ...this.httpOptions.headers,
+      },
+      responseType: 'stream',
+      body: JSON.stringify(req),
+      signal,
+    });
+
+    return (async function* (): AsyncGenerator<T> {
+      const rl = readline.createInterface({
+        input: res.data as NodeJS.ReadableStream,
+        crlfDelay: Infinity, // Recognizes '\r\n' and '\n' as line breaks
+      });
+
+      let bufferedLines: string[] = [];
+      for await (const line of rl) {
+        // blank lines are used to separate JSON objects in the stream
+        if (line === '') {
+          if (bufferedLines.length === 0) {
+            continue; // no data to yield
+          }
+          yield JSON.parse(bufferedLines.join('\n')) as T;
+          bufferedLines = []; // Reset the buffer after yielding
+        } else if (line.startsWith('data: ')) {
+          bufferedLines.push(line.slice(6).trim());
+        } else {
+          throw new Error(`Unexpected line format in response: ${line}`);
+        }
+      }
+    })();
+  }
+
+  getMethodUrl(method: string): string {
+    const endpoint =
+      process.env['CODE_ASSIST_ENDPOINT'] ?? CODE_ASSIST_ENDPOINT;
+    return `${endpoint}/${CODE_ASSIST_API_VERSION}:${method}`;
+  }
+}
+
+function isVpcScAffectedUser(error: unknown): boolean {
+  if (error && typeof error === 'object' && 'response' in error) {
+    const gaxiosError = error as {
+      response?: {
+        data?: unknown;
+      };
+    };
+    const response = gaxiosError.response?.data as
+      | GoogleRpcResponse
+      | undefined;
+    if (Array.isArray(response?.error?.details)) {
+      return response.error.details.some(
+        (detail) => detail.reason === 'SECURITY_POLICY_VIOLATED',
+      );
+    }
+  }
+  return false;
+}
--- a/packages/core/src/code_assist/setup.test.ts
+++ b/packages/core/src/code_assist/setup.test.ts
@@ -0,0 +1,224 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { setupUser, ProjectIdRequiredError } from './setup.js';
+import { CodeAssistServer } from '../code_assist/server.js';
+import type { OAuth2Client } from 'google-auth-library';
+import type { GeminiUserTier } from './types.js';
+import { UserTierId } from './types.js';
+
+vi.mock('../code_assist/server.js');
+
+const mockPaidTier: GeminiUserTier = {
+  id: UserTierId.STANDARD,
+  name: 'paid',
+  description: 'Paid tier',
+  isDefault: true,
+};
+
+const mockFreeTier: GeminiUserTier = {
+  id: UserTierId.FREE,
+  name: 'free',
+  description: 'Free tier',
+  isDefault: true,
+};
+
+describe('setupUser for existing user', () => {
+  let mockLoad: ReturnType<typeof vi.fn>;
+  let mockOnboardUser: ReturnType<typeof vi.fn>;
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+    mockLoad = vi.fn();
+    mockOnboardUser = vi.fn().mockResolvedValue({
+      done: true,
+      response: {
+        cloudaicompanionProject: {
+          id: 'server-project',
+        },
+      },
+    });
+    vi.mocked(CodeAssistServer).mockImplementation(
+      () =>
+        ({
+          loadCodeAssist: mockLoad,
+          onboardUser: mockOnboardUser,
+        }) as unknown as CodeAssistServer,
+    );
+  });
+
+  afterEach(() => {
+    vi.unstubAllEnvs();
+  });
+
+  it('should use GOOGLE_CLOUD_PROJECT when set and project from server is undefined', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', 'test-project');
+    mockLoad.mockResolvedValue({
+      currentTier: mockPaidTier,
+    });
+    await setupUser({} as OAuth2Client);
+    expect(CodeAssistServer).toHaveBeenCalledWith(
+      {},
+      'test-project',
+      {},
+      '',
+      undefined,
+    );
+  });
+
+  it('should ignore GOOGLE_CLOUD_PROJECT when project from server is set', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', 'test-project');
+    mockLoad.mockResolvedValue({
+      cloudaicompanionProject: 'server-project',
+      currentTier: mockPaidTier,
+    });
+    const projectId = await setupUser({} as OAuth2Client);
+    expect(CodeAssistServer).toHaveBeenCalledWith(
+      {},
+      'test-project',
+      {},
+      '',
+      undefined,
+    );
+    expect(projectId).toEqual({
+      projectId: 'server-project',
+      userTier: 'standard-tier',
+    });
+  });
+
+  it('should throw ProjectIdRequiredError when no project ID is available', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', '');
+    // And the server itself requires a project ID internally
+    vi.mocked(CodeAssistServer).mockImplementation(() => {
+      throw new ProjectIdRequiredError();
+    });
+
+    await expect(setupUser({} as OAuth2Client)).rejects.toThrow(
+      ProjectIdRequiredError,
+    );
+  });
+});
+
+describe('setupUser for new user', () => {
+  let mockLoad: ReturnType<typeof vi.fn>;
+  let mockOnboardUser: ReturnType<typeof vi.fn>;
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+    mockLoad = vi.fn();
+    mockOnboardUser = vi.fn().mockResolvedValue({
+      done: true,
+      response: {
+        cloudaicompanionProject: {
+          id: 'server-project',
+        },
+      },
+    });
+    vi.mocked(CodeAssistServer).mockImplementation(
+      () =>
+        ({
+          loadCodeAssist: mockLoad,
+          onboardUser: mockOnboardUser,
+        }) as unknown as CodeAssistServer,
+    );
+  });
+
+  afterEach(() => {
+    vi.unstubAllEnvs();
+  });
+
+  it('should use GOOGLE_CLOUD_PROJECT when set and onboard a new paid user', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', 'test-project');
+    mockLoad.mockResolvedValue({
+      allowedTiers: [mockPaidTier],
+    });
+    const userData = await setupUser({} as OAuth2Client);
+    expect(CodeAssistServer).toHaveBeenCalledWith(
+      {},
+      'test-project',
+      {},
+      '',
+      undefined,
+    );
+    expect(mockLoad).toHaveBeenCalled();
+    expect(mockOnboardUser).toHaveBeenCalledWith({
+      tierId: 'standard-tier',
+      cloudaicompanionProject: 'test-project',
+      metadata: {
+        ideType: 'IDE_UNSPECIFIED',
+        platform: 'PLATFORM_UNSPECIFIED',
+        pluginType: 'GEMINI',
+        duetProject: 'test-project',
+      },
+    });
+    expect(userData).toEqual({
+      projectId: 'server-project',
+      userTier: 'standard-tier',
+    });
+  });
+
+  it('should onboard a new free user when GOOGLE_CLOUD_PROJECT is not set', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', '');
+    mockLoad.mockResolvedValue({
+      allowedTiers: [mockFreeTier],
+    });
+    const userData = await setupUser({} as OAuth2Client);
+    expect(CodeAssistServer).toHaveBeenCalledWith(
+      {},
+      undefined,
+      {},
+      '',
+      undefined,
+    );
+    expect(mockLoad).toHaveBeenCalled();
+    expect(mockOnboardUser).toHaveBeenCalledWith({
+      tierId: 'free-tier',
+      cloudaicompanionProject: undefined,
+      metadata: {
+        ideType: 'IDE_UNSPECIFIED',
+        platform: 'PLATFORM_UNSPECIFIED',
+        pluginType: 'GEMINI',
+      },
+    });
+    expect(userData).toEqual({
+      projectId: 'server-project',
+      userTier: 'free-tier',
+    });
+  });
+
+  it('should use GOOGLE_CLOUD_PROJECT when onboard response has no project ID', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', 'test-project');
+    mockLoad.mockResolvedValue({
+      allowedTiers: [mockPaidTier],
+    });
+    mockOnboardUser.mockResolvedValue({
+      done: true,
+      response: {
+        cloudaicompanionProject: undefined,
+      },
+    });
+    const userData = await setupUser({} as OAuth2Client);
+    expect(userData).toEqual({
+      projectId: 'test-project',
+      userTier: 'standard-tier',
+    });
+  });
+
+  it('should throw ProjectIdRequiredError when no project ID is available', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', '');
+    mockLoad.mockResolvedValue({
+      allowedTiers: [mockPaidTier],
+    });
+    mockOnboardUser.mockResolvedValue({
+      done: true,
+      response: {},
+    });
+    await expect(setupUser({} as OAuth2Client)).rejects.toThrow(
+      ProjectIdRequiredError,
+    );
+  });
+});
--- a/packages/core/src/code_assist/setup.ts
+++ b/packages/core/src/code_assist/setup.ts
@@ -0,0 +1,124 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type {
+  ClientMetadata,
+  GeminiUserTier,
+  LoadCodeAssistResponse,
+  OnboardUserRequest,
+} from './types.js';
+import { UserTierId } from './types.js';
+import { CodeAssistServer } from './server.js';
+import type { OAuth2Client } from 'google-auth-library';
+
+export class ProjectIdRequiredError extends Error {
+  constructor() {
+    super(
+      'This account requires setting the GOOGLE_CLOUD_PROJECT env var. See https://goo.gle/gemini-cli-auth-docs#workspace-gca',
+    );
+  }
+}
+
+export interface UserData {
+  projectId: string;
+  userTier: UserTierId;
+}
+
+/**
+ *
+ * @param projectId the user's project id, if any
+ * @returns the user's actual project id
+ */
+export async function setupUser(client: OAuth2Client): Promise<UserData> {
+  const projectId = process.env['GOOGLE_CLOUD_PROJECT'] || undefined;
+  const caServer = new CodeAssistServer(client, projectId, {}, '', undefined);
+  const coreClientMetadata: ClientMetadata = {
+    ideType: 'IDE_UNSPECIFIED',
+    platform: 'PLATFORM_UNSPECIFIED',
+    pluginType: 'GEMINI',
+  };
+
+  const loadRes = await caServer.loadCodeAssist({
+    cloudaicompanionProject: projectId,
+    metadata: {
+      ...coreClientMetadata,
+      duetProject: projectId,
+    },
+  });
+
+  if (loadRes.currentTier) {
+    if (!loadRes.cloudaicompanionProject) {
+      if (projectId) {
+        return {
+          projectId,
+          userTier: loadRes.currentTier.id,
+        };
+      }
+      throw new ProjectIdRequiredError();
+    }
+    return {
+      projectId: loadRes.cloudaicompanionProject,
+      userTier: loadRes.currentTier.id,
+    };
+  }
+
+  const tier = getOnboardTier(loadRes);
+
+  let onboardReq: OnboardUserRequest;
+  if (tier.id === UserTierId.FREE) {
+    // The free tier uses a managed google cloud project. Setting a project in the `onboardUser` request causes a `Precondition Failed` error.
+    onboardReq = {
+      tierId: tier.id,
+      cloudaicompanionProject: undefined,
+      metadata: coreClientMetadata,
+    };
+  } else {
+    onboardReq = {
+      tierId: tier.id,
+      cloudaicompanionProject: projectId,
+      metadata: {
+        ...coreClientMetadata,
+        duetProject: projectId,
+      },
+    };
+  }
+
+  // Poll onboardUser until long running operation is complete.
+  let lroRes = await caServer.onboardUser(onboardReq);
+  while (!lroRes.done) {
+    await new Promise((f) => setTimeout(f, 5000));
+    lroRes = await caServer.onboardUser(onboardReq);
+  }
+
+  if (!lroRes.response?.cloudaicompanionProject?.id) {
+    if (projectId) {
+      return {
+        projectId,
+        userTier: tier.id,
+      };
+    }
+    throw new ProjectIdRequiredError();
+  }
+
+  return {
+    projectId: lroRes.response.cloudaicompanionProject.id,
+    userTier: tier.id,
+  };
+}
+
+function getOnboardTier(res: LoadCodeAssistResponse): GeminiUserTier {
+  for (const tier of res.allowedTiers || []) {
+    if (tier.isDefault) {
+      return tier;
+    }
+  }
+  return {
+    name: '',
+    description: '',
+    id: UserTierId.LEGACY,
+    userDefinedCloudaicompanionProject: true,
+  };
+}
--- a/packages/core/src/code_assist/types.ts
+++ b/packages/core/src/code_assist/types.ts
@@ -0,0 +1,201 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export interface ClientMetadata {
+  ideType?: ClientMetadataIdeType;
+  ideVersion?: string;
+  pluginVersion?: string;
+  platform?: ClientMetadataPlatform;
+  updateChannel?: string;
+  duetProject?: string;
+  pluginType?: ClientMetadataPluginType;
+  ideName?: string;
+}
+
+export type ClientMetadataIdeType =
+  | 'IDE_UNSPECIFIED'
+  | 'VSCODE'
+  | 'INTELLIJ'
+  | 'VSCODE_CLOUD_WORKSTATION'
+  | 'INTELLIJ_CLOUD_WORKSTATION'
+  | 'CLOUD_SHELL';
+export type ClientMetadataPlatform =
+  | 'PLATFORM_UNSPECIFIED'
+  | 'DARWIN_AMD64'
+  | 'DARWIN_ARM64'
+  | 'LINUX_AMD64'
+  | 'LINUX_ARM64'
+  | 'WINDOWS_AMD64';
+export type ClientMetadataPluginType =
+  | 'PLUGIN_UNSPECIFIED'
+  | 'CLOUD_CODE'
+  | 'GEMINI'
+  | 'AIPLUGIN_INTELLIJ'
+  | 'AIPLUGIN_STUDIO';
+
+export interface LoadCodeAssistRequest {
+  cloudaicompanionProject?: string;
+  metadata: ClientMetadata;
+}
+
+/**
+ * Represents LoadCodeAssistResponse proto json field
+ * http://google3/google/internal/cloud/code/v1internal/cloudcode.proto;l=224
+ */
+export interface LoadCodeAssistResponse {
+  currentTier?: GeminiUserTier | null;
+  allowedTiers?: GeminiUserTier[] | null;
+  ineligibleTiers?: IneligibleTier[] | null;
+  cloudaicompanionProject?: string | null;
+}
+
+/**
+ * GeminiUserTier reflects the structure received from the CodeAssist when calling LoadCodeAssist.
+ */
+export interface GeminiUserTier {
+  id: UserTierId;
+  name?: string;
+  description?: string;
+  // This value is used to declare whether a given tier requires the user to configure the project setting on the IDE settings or not.
+  userDefinedCloudaicompanionProject?: boolean | null;
+  isDefault?: boolean;
+  privacyNotice?: PrivacyNotice;
+  hasAcceptedTos?: boolean;
+  hasOnboardedPreviously?: boolean;
+}
+
+/**
+ * Includes information specifying the reasons for a user's ineligibility for a specific tier.
+ * @param reasonCode mnemonic code representing the reason for in-eligibility.
+ * @param reasonMessage message to display to the user.
+ * @param tierId id of the tier.
+ * @param tierName name of the tier.
+ */
+export interface IneligibleTier {
+  reasonCode: IneligibleTierReasonCode;
+  reasonMessage: string;
+  tierId: UserTierId;
+  tierName: string;
+}
+
+/**
+ * List of predefined reason codes when a tier is blocked from a specific tier.
+ * https://source.corp.google.com/piper///depot/google3/google/internal/cloud/code/v1internal/cloudcode.proto;l=378
+ */
+export enum IneligibleTierReasonCode {
+  // go/keep-sorted start
+  DASHER_USER = 'DASHER_USER',
+  INELIGIBLE_ACCOUNT = 'INELIGIBLE_ACCOUNT',
+  NON_USER_ACCOUNT = 'NON_USER_ACCOUNT',
+  RESTRICTED_AGE = 'RESTRICTED_AGE',
+  RESTRICTED_NETWORK = 'RESTRICTED_NETWORK',
+  UNKNOWN = 'UNKNOWN',
+  UNKNOWN_LOCATION = 'UNKNOWN_LOCATION',
+  UNSUPPORTED_LOCATION = 'UNSUPPORTED_LOCATION',
+  // go/keep-sorted end
+}
+/**
+ * UserTierId represents IDs returned from the Cloud Code Private API representing a user's tier
+ *
+ * //depot/google3/cloud/developer_experience/cloudcode/pa/service/usertier.go;l=16
+ */
+export enum UserTierId {
+  FREE = 'free-tier',
+  LEGACY = 'legacy-tier',
+  STANDARD = 'standard-tier',
+}
+
+/**
+ * PrivacyNotice reflects the structure received from the CodeAssist in regards to a tier
+ * privacy notice.
+ */
+export interface PrivacyNotice {
+  showNotice: boolean;
+  noticeText?: string;
+}
+
+/**
+ * Proto signature of OnboardUserRequest as payload to OnboardUser call
+ */
+export interface OnboardUserRequest {
+  tierId: string | undefined;
+  cloudaicompanionProject: string | undefined;
+  metadata: ClientMetadata | undefined;
+}
+
+/**
+ * Represents LongRunningOperation proto
+ * http://google3/google/longrunning/operations.proto;rcl=698857719;l=107
+ */
+export interface LongRunningOperationResponse {
+  name: string;
+  done?: boolean;
+  response?: OnboardUserResponse;
+}
+
+/**
+ * Represents OnboardUserResponse proto
+ * http://google3/google/internal/cloud/code/v1internal/cloudcode.proto;l=215
+ */
+export interface OnboardUserResponse {
+  // tslint:disable-next-line:enforce-name-casing This is the name of the field in the proto.
+  cloudaicompanionProject?: {
+    id: string;
+    name: string;
+  };
+}
+
+/**
+ * Status code of user license status
+ * it does not strictly correspond to the proto
+ * Error value is an additional value assigned to error responses from OnboardUser
+ */
+export enum OnboardUserStatusCode {
+  Default = 'DEFAULT',
+  Notice = 'NOTICE',
+  Warning = 'WARNING',
+  Error = 'ERROR',
+}
+
+/**
+ * Status of user onboarded to gemini
+ */
+export interface OnboardUserStatus {
+  statusCode: OnboardUserStatusCode;
+  displayMessage: string;
+  helpLink: HelpLinkUrl | undefined;
+}
+
+export interface HelpLinkUrl {
+  description: string;
+  url: string;
+}
+
+export interface SetCodeAssistGlobalUserSettingRequest {
+  cloudaicompanionProject?: string;
+  freeTierDataCollectionOptin: boolean;
+}
+
+export interface CodeAssistGlobalUserSettingResponse {
+  cloudaicompanionProject?: string;
+  freeTierDataCollectionOptin: boolean;
+}
+
+/**
+ * Relevant fields that can be returned from a Google RPC response
+ */
+export interface GoogleRpcResponse {
+  error?: {
+    details?: GoogleRpcErrorInfo[];
+  };
+}
+
+/**
+ * Relevant fields that can be returned in the details of an error returned from GoogleRPCs
+ */
+interface GoogleRpcErrorInfo {
+  reason?: string;
+}
--- a/packages/core/src/config/config.test.ts
+++ b/packages/core/src/config/config.test.ts
@@ -283,6 +283,23 @@ describe('Server Config (config.ts)', () => {
      expect(config.isInFallbackMode()).toBe(false);
    });

+    it('should strip thoughts when switching from GenAI to Vertex', async () => {
+      const config = new Config(baseParams);
+
+      vi.mocked(createContentGeneratorConfig).mockImplementation(
+        (_: Config, authType: AuthType | undefined) =>
+          ({ authType }) as unknown as ContentGeneratorConfig,
+      );
+
+      await config.refreshAuth(AuthType.USE_GEMINI);
+
+      await config.refreshAuth(AuthType.LOGIN_WITH_GOOGLE);
+
+      expect(
+        config.getGeminiClient().stripThoughtsFromHistory,
+      ).toHaveBeenCalledWith();
+    });
+
    it('should not strip thoughts when switching from Vertex to GenAI', async () => {
      const config = new Config(baseParams);

--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -16,7 +16,6 @@ import { ProxyAgent, setGlobalDispatcher } from 'undici';
 import type {
  ContentGenerator,
  ContentGeneratorConfig,
-  AuthType,
 } from '../core/contentGenerator.js';
 import type { FallbackModelHandler } from '../fallback/types.js';
 import type { MCPOAuthConfig } from '../mcp/oauth-provider.js';
@@ -27,6 +26,7 @@ import type { AnyToolInvocation } from '../tools/tools.js';
 import { BaseLlmClient } from '../core/baseLlmClient.js';
 import { GeminiClient } from '../core/client.js';
 import {
+  AuthType,
  createContentGenerator,
  createContentGeneratorConfig,
 } from '../core/contentGenerator.js';
@@ -54,6 +54,7 @@ import { canUseRipgrep } from '../utils/ripgrepUtils.js';
 import { RipGrepTool } from '../tools/ripGrep.js';
 import { ShellTool } from '../tools/shell.js';
 import { SmartEditTool } from '../tools/smart-edit.js';
+import { SkillTool } from '../tools/skill.js';
 import { TaskTool } from '../tools/task.js';
 import { TodoWriteTool } from '../tools/todoWrite.js';
 import { ToolRegistry } from '../tools/tool-registry.js';
@@ -65,6 +66,7 @@ import { WriteFileTool } from '../tools/write-file.js';
 import { ideContextStore } from '../ide/ideContext.js';
 import { InputFormat, OutputFormat } from '../output/types.js';
 import { PromptRegistry } from '../prompts/prompt-registry.js';
+import { SkillManager } from '../skills/skill-manager.js';
 import { SubagentManager } from '../subagents/subagent-manager.js';
 import type { SubagentConfig } from '../subagents/types.js';
 import {
@@ -305,6 +307,7 @@ export interface ConfigParameters {
  extensionContextFilePaths?: string[];
  maxSessionTurns?: number;
  sessionTokenLimit?: number;
+  experimentalSkills?: boolean;
  experimentalZedIntegration?: boolean;
  listExtensions?: boolean;
  extensions?: GeminiCLIExtension[];
@@ -389,6 +392,7 @@ export class Config {
  private toolRegistry!: ToolRegistry;
  private promptRegistry!: PromptRegistry;
  private subagentManager!: SubagentManager;
+  private skillManager!: SkillManager;
  private fileSystemService: FileSystemService;
  private contentGeneratorConfig!: ContentGeneratorConfig;
  private contentGenerator!: ContentGenerator;
@@ -458,6 +462,7 @@ export class Config {
    | undefined;
  private readonly cliVersion?: string;
  private readonly experimentalZedIntegration: boolean = false;
+  private readonly experimentalSkills: boolean = false;
  private readonly chatRecordingEnabled: boolean;
  private readonly loadMemoryFromIncludeDirectories: boolean = false;
  private readonly webSearch?: {
@@ -557,6 +562,7 @@ export class Config {
    this.sessionTokenLimit = params.sessionTokenLimit ?? -1;
    this.experimentalZedIntegration =
      params.experimentalZedIntegration ?? false;
+    this.experimentalSkills = params.experimentalSkills ?? false;
    this.listExtensions = params.listExtensions ?? false;
    this._extensions = params.extensions ?? [];
    this._blockedMcpServers = params.blockedMcpServers ?? [];
@@ -644,6 +650,7 @@ export class Config {
    }
    this.promptRegistry = new PromptRegistry();
    this.subagentManager = new SubagentManager(this);
+    this.skillManager = new SkillManager(this);

    // Load session subagents if they were provided before initialization
    if (this.sessionSubagents.length > 0) {
@@ -684,6 +691,16 @@ export class Config {
  }

  async refreshAuth(authMethod: AuthType, isInitialAuth?: boolean) {
+    // Vertex and Genai have incompatible encryption and sending history with
+    // throughtSignature from Genai to Vertex will fail, we need to strip them
+    if (
+      this.contentGeneratorConfig?.authType === AuthType.USE_GEMINI &&
+      authMethod === AuthType.LOGIN_WITH_GOOGLE
+    ) {
+      // Restore the conversation history to the new client
+      this.geminiClient.stripThoughtsFromHistory();
+    }
+
    const newContentGeneratorConfig = createContentGeneratorConfig(
      this,
      authMethod,
@@ -1066,6 +1083,10 @@ export class Config {
    return this.experimentalZedIntegration;
  }

+  getExperimentalSkills(): boolean {
+    return this.experimentalSkills;
+  }
+
  getListExtensions(): boolean {
    return this.listExtensions;
  }
@@ -1296,6 +1317,10 @@ export class Config {
    return this.subagentManager;
  }

+  getSkillManager(): SkillManager {
+    return this.skillManager;
+  }
+
  async createToolRegistry(
    sendSdkMcpMessage?: SendSdkMcpMessage,
  ): Promise<ToolRegistry> {
@@ -1338,6 +1363,9 @@ export class Config {
    };

    registerCoreTool(TaskTool, this);
+    if (this.getExperimentalSkills()) {
+      registerCoreTool(SkillTool, this);
+    }
    registerCoreTool(LSTool, this);
    registerCoreTool(ReadFileTool, this);

--- a/packages/core/src/config/flashFallback.test.ts
+++ b/packages/core/src/config/flashFallback.test.ts
@@ -31,7 +31,7 @@ describe('Flash Model Fallback Configuration', () => {
      config as unknown as { contentGeneratorConfig: unknown }
    ).contentGeneratorConfig = {
      model: DEFAULT_GEMINI_MODEL,
-      authType: 'gemini-api-key',
+      authType: 'oauth-personal',
    };
  });

--- a/packages/core/src/config/storage.ts
+++ b/packages/core/src/config/storage.ts
@@ -126,6 +126,10 @@ export class Storage {
    return path.join(this.getExtensionsDir(), 'qwen-extension.json');
  }

+  getUserSkillsDir(): string {
+    return path.join(Storage.getGlobalQwenDir(), 'skills');
+  }
+
  getHistoryFilePath(): string {
    return path.join(this.getProjectTempDir(), 'shell_history');
  }
--- a/packages/core/src/core/tests/openaiTimeoutHandling.test.ts
+++ b/packages/core/src/core/tests/openaiTimeoutHandling.test.ts
@@ -73,7 +73,6 @@ describe('OpenAIContentGenerator Timeout Handling', () => {
      }),
      buildClient: vi.fn().mockReturnValue(mockOpenAIClient),
      buildRequest: vi.fn().mockImplementation((req) => req),
-      getDefaultGenerationConfig: vi.fn().mockReturnValue({}),
    };

    // Create generator instance
@@ -300,7 +299,6 @@ describe('OpenAIContentGenerator Timeout Handling', () => {
        }),
        buildClient: vi.fn().mockReturnValue(mockOpenAIClient),
        buildRequest: vi.fn().mockImplementation((req) => req),
-        getDefaultGenerationConfig: vi.fn().mockReturnValue({}),
      };

      new OpenAIContentGenerator(
@@ -335,7 +333,6 @@ describe('OpenAIContentGenerator Timeout Handling', () => {
        }),
        buildClient: vi.fn().mockReturnValue(mockOpenAIClient),
        buildRequest: vi.fn().mockImplementation((req) => req),
-        getDefaultGenerationConfig: vi.fn().mockReturnValue({}),
      };

      new OpenAIContentGenerator(
--- a/packages/core/src/core/baseLlmClient.test.ts
+++ b/packages/core/src/core/baseLlmClient.test.ts
@@ -146,11 +146,12 @@ describe('BaseLlmClient', () => {
      // Validate the parameters passed to the underlying generator
      expect(mockGenerateContent).toHaveBeenCalledTimes(1);
      expect(mockGenerateContent).toHaveBeenCalledWith(
-        expect.objectContaining({
+        {
          model: 'test-model',
          contents: defaultOptions.contents,
-          config: expect.objectContaining({
+          config: {
            abortSignal: defaultOptions.abortSignal,
+            topP: 0.8,
            tools: [
              {
                functionDeclarations: [
@@ -162,8 +163,9 @@ describe('BaseLlmClient', () => {
                ],
              },
            ],
-          }),
-        }),
+            // Crucial: systemInstruction should NOT be in the config object if not provided
+          },
+        },
        'test-prompt-id',
      );
    });
@@ -186,6 +188,7 @@ describe('BaseLlmClient', () => {
        expect.objectContaining({
          config: expect.objectContaining({
            temperature: 0.8,
+            topP: 0.8, // Default should remain if not overridden
            topK: 10,
            tools: expect.any(Array),
          }),
--- a/packages/core/src/core/baseLlmClient.ts
+++ b/packages/core/src/core/baseLlmClient.ts
@@ -64,6 +64,11 @@ export interface GenerateJsonOptions {
 * A client dedicated to stateless, utility-focused LLM calls.
 */
 export class BaseLlmClient {
+  // Default configuration for utility tasks
+  private readonly defaultUtilityConfig: GenerateContentConfig = {
+    topP: 0.8,
+  };
+
  constructor(
    private readonly contentGenerator: ContentGenerator,
    private readonly config: Config,
@@ -84,6 +89,7 @@ export class BaseLlmClient {

    const requestConfig: GenerateContentConfig = {
      abortSignal,
+      ...this.defaultUtilityConfig,
      ...options.config,
      ...(systemInstruction && { systemInstruction }),
    };
--- a/packages/core/src/core/client.test.ts
+++ b/packages/core/src/core/client.test.ts
@@ -15,7 +15,11 @@ import {
 } from 'vitest';

 import type { Content, GenerateContentResponse, Part } from '@google/genai';
-import { GeminiClient } from './client.js';
+import {
+  isThinkingDefault,
+  isThinkingSupported,
+  GeminiClient,
+} from './client.js';
 import { findCompressSplitPoint } from '../services/chatCompressionService.js';
 import {
  AuthType,
@@ -243,6 +247,40 @@ describe('findCompressSplitPoint', () => {
  });
 });

+describe('isThinkingSupported', () => {
+  it('should return true for gemini-2.5', () => {
+    expect(isThinkingSupported('gemini-2.5')).toBe(true);
+  });
+
+  it('should return true for gemini-2.5-pro', () => {
+    expect(isThinkingSupported('gemini-2.5-pro')).toBe(true);
+  });
+
+  it('should return false for other models', () => {
+    expect(isThinkingSupported('gemini-1.5-flash')).toBe(false);
+    expect(isThinkingSupported('some-other-model')).toBe(false);
+  });
+});
+
+describe('isThinkingDefault', () => {
+  it('should return false for gemini-2.5-flash-lite', () => {
+    expect(isThinkingDefault('gemini-2.5-flash-lite')).toBe(false);
+  });
+
+  it('should return true for gemini-2.5', () => {
+    expect(isThinkingDefault('gemini-2.5')).toBe(true);
+  });
+
+  it('should return true for gemini-2.5-pro', () => {
+    expect(isThinkingDefault('gemini-2.5-pro')).toBe(true);
+  });
+
+  it('should return false for other models', () => {
+    expect(isThinkingDefault('gemini-1.5-flash')).toBe(false);
+    expect(isThinkingDefault('some-other-model')).toBe(false);
+  });
+});
+
 describe('Gemini Client (client.ts)', () => {
  let mockContentGenerator: ContentGenerator;
  let mockConfig: Config;
@@ -2266,15 +2304,16 @@ ${JSON.stringify(
      );

      expect(mockContentGenerator.generateContent).toHaveBeenCalledWith(
-        expect.objectContaining({
+        {
          model: DEFAULT_GEMINI_FLASH_MODEL,
-          config: expect.objectContaining({
+          config: {
            abortSignal,
            systemInstruction: getCoreSystemPrompt(''),
            temperature: 0.5,
-          }),
+            topP: 0.8,
+          },
          contents,
-        }),
+        },
        'test-session-id',
      );
    });
--- a/packages/core/src/core/client.ts
+++ b/packages/core/src/core/client.ts
@@ -15,7 +15,11 @@ import type {

 // Config
 import { ApprovalMode, type Config } from '../config/config.js';
-import { DEFAULT_GEMINI_FLASH_MODEL } from '../config/models.js';
+import {
+  DEFAULT_GEMINI_FLASH_MODEL,
+  DEFAULT_GEMINI_MODEL_AUTO,
+  DEFAULT_THINKING_MODE,
+} from '../config/models.js';

 // Core modules
 import type { ContentGenerator } from './contentGenerator.js';
@@ -74,10 +78,24 @@ import { type File, type IdeContext } from '../ide/types.js';
 // Fallback handling
 import { handleFallback } from '../fallback/handler.js';

+export function isThinkingSupported(model: string) {
+  return model.startsWith('gemini-2.5') || model === DEFAULT_GEMINI_MODEL_AUTO;
+}
+
+export function isThinkingDefault(model: string) {
+  if (model.startsWith('gemini-2.5-flash-lite')) {
+    return false;
+  }
+  return model.startsWith('gemini-2.5') || model === DEFAULT_GEMINI_MODEL_AUTO;
+}
+
 const MAX_TURNS = 100;

 export class GeminiClient {
  private chat?: GeminiChat;
+  private readonly generateContentConfig: GenerateContentConfig = {
+    topP: 0.8,
+  };
  private sessionTurnCount = 0;

  private readonly loopDetector: LoopDetectionService;
@@ -189,10 +207,20 @@ export class GeminiClient {
      const model = this.config.getModel();
      const systemInstruction = getCoreSystemPrompt(userMemory, model);

+      const config: GenerateContentConfig = { ...this.generateContentConfig };
+
+      if (isThinkingSupported(model)) {
+        config.thinkingConfig = {
+          includeThoughts: true,
+          thinkingBudget: DEFAULT_THINKING_MODE,
+        };
+      }
+
      return new GeminiChat(
        this.config,
        {
          systemInstruction,
+          ...config,
          tools,
        },
        history,
@@ -589,6 +617,11 @@ export class GeminiClient {
  ): Promise<GenerateContentResponse> {
    let currentAttemptModel: string = model;

+    const configToUse: GenerateContentConfig = {
+      ...this.generateContentConfig,
+      ...generationConfig,
+    };
+
    try {
      const userMemory = this.config.getUserMemory();
      const finalSystemInstruction = generationConfig.systemInstruction
@@ -597,7 +630,7 @@ export class GeminiClient {

      const requestConfig: GenerateContentConfig = {
        abortSignal,
-        ...generationConfig,
+        ...configToUse,
        systemInstruction: finalSystemInstruction,
      };

@@ -638,7 +671,7 @@ export class GeminiClient {
        `Error generating content via API with model ${currentAttemptModel}.`,
        {
          requestContents: contents,
-          requestConfig: generationConfig,
+          requestConfig: configToUse,
        },
        'generateContent-api',
      );
--- a/packages/core/src/core/contentGenerator.test.ts
+++ b/packages/core/src/core/contentGenerator.test.ts
@@ -5,19 +5,42 @@
 */

 import { describe, it, expect, vi } from 'vitest';
+import type { ContentGenerator } from './contentGenerator.js';
 import { createContentGenerator, AuthType } from './contentGenerator.js';
+import { createCodeAssistContentGenerator } from '../code_assist/codeAssist.js';
 import { GoogleGenAI } from '@google/genai';
 import type { Config } from '../config/config.js';
-import { LoggingContentGenerator } from './geminiContentGenerator/loggingContentGenerator.js';
+import { LoggingContentGenerator } from './loggingContentGenerator.js';

+vi.mock('../code_assist/codeAssist.js');
 vi.mock('@google/genai');

+const mockConfig = {
+  getCliVersion: vi.fn().mockReturnValue('1.0.0'),
+} as unknown as Config;
+
 describe('createContentGenerator', () => {
-  it('should create a Gemini content generator', async () => {
+  it('should create a CodeAssistContentGenerator', async () => {
+    const mockGenerator = {} as unknown as ContentGenerator;
+    vi.mocked(createCodeAssistContentGenerator).mockResolvedValue(
+      mockGenerator as never,
+    );
+    const generator = await createContentGenerator(
+      {
+        model: 'test-model',
+        authType: AuthType.LOGIN_WITH_GOOGLE,
+      },
+      mockConfig,
+    );
+    expect(createCodeAssistContentGenerator).toHaveBeenCalled();
+    expect(generator).toEqual(
+      new LoggingContentGenerator(mockGenerator, mockConfig),
+    );
+  });
+
+  it('should create a GoogleGenAI content generator', async () => {
    const mockConfig = {
      getUsageStatisticsEnabled: () => true,
-      getContentGeneratorConfig: () => ({}),
-      getCliVersion: () => '1.0.0',
    } as unknown as Config;

    const mockGenerator = {
@@ -42,17 +65,17 @@ describe('createContentGenerator', () => {
        },
      },
    });
-    // We expect it to be a LoggingContentGenerator wrapping a GeminiContentGenerator
-    expect(generator).toBeInstanceOf(LoggingContentGenerator);
-    const wrapped = (generator as LoggingContentGenerator).getWrapped();
-    expect(wrapped).toBeDefined();
+    expect(generator).toEqual(
+      new LoggingContentGenerator(
+        (mockGenerator as GoogleGenAI).models,
+        mockConfig,
+      ),
+    );
  });

-  it('should create a Gemini content generator with client install id logging disabled', async () => {
+  it('should create a GoogleGenAI content generator with client install id logging disabled', async () => {
    const mockConfig = {
      getUsageStatisticsEnabled: () => false,
-      getContentGeneratorConfig: () => ({}),
-      getCliVersion: () => '1.0.0',
    } as unknown as Config;
    const mockGenerator = {
      models: {},
@@ -75,6 +98,11 @@ describe('createContentGenerator', () => {
        },
      },
    });
-    expect(generator).toBeInstanceOf(LoggingContentGenerator);
+    expect(generator).toEqual(
+      new LoggingContentGenerator(
+        (mockGenerator as GoogleGenAI).models,
+        mockConfig,
+      ),
+    );
  });
 });
--- a/packages/core/src/core/contentGenerator.ts
+++ b/packages/core/src/core/contentGenerator.ts
@@ -12,9 +12,15 @@ import type {
  GenerateContentParameters,
  GenerateContentResponse,
 } from '@google/genai';
+import { GoogleGenAI } from '@google/genai';
+import { createCodeAssistContentGenerator } from '../code_assist/codeAssist.js';
 import { DEFAULT_QWEN_MODEL } from '../config/models.js';
 import type { Config } from '../config/config.js';

+import type { UserTierId } from '../code_assist/types.js';
+import { InstallationManager } from '../utils/installationManager.js';
+import { LoggingContentGenerator } from './loggingContentGenerator.js';
+
 /**
 * Interface abstracting the core functionalities for generating content and counting tokens.
 */
@@ -33,12 +39,14 @@ export interface ContentGenerator {

  embedContent(request: EmbedContentParameters): Promise<EmbedContentResponse>;

-  useSummarizedThinking(): boolean;
+  userTier?: UserTierId;
 }

 export enum AuthType {
+  LOGIN_WITH_GOOGLE = 'oauth-personal',
  USE_GEMINI = 'gemini-api-key',
  USE_VERTEX_AI = 'vertex-ai',
+  CLOUD_SHELL = 'cloud-shell',
  USE_OPENAI = 'openai',
  QWEN_OAUTH = 'qwen-oauth',
 }
@@ -51,9 +59,12 @@ export type ContentGeneratorConfig = {
  authType?: AuthType | undefined;
  enableOpenAILogging?: boolean;
  openAILoggingDir?: string;
-  timeout?: number; // Timeout configuration in milliseconds
-  maxRetries?: number; // Maximum retries for failed requests
-  disableCacheControl?: boolean; // Disable cache control for DashScope providers
+  // Timeout configuration in milliseconds
+  timeout?: number;
+  // Maximum retries for failed requests
+  maxRetries?: number;
+  // Disable cache control for DashScope providers
+  disableCacheControl?: boolean;
  samplingParams?: {
    top_p?: number;
    top_k?: number;
@@ -63,9 +74,6 @@ export type ContentGeneratorConfig = {
    temperature?: number;
    max_tokens?: number;
  };
-  reasoning?: {
-    effort?: 'low' | 'medium' | 'high';
-  };
  proxy?: string | undefined;
  userAgent?: string;
  // Schema compliance mode for tool definitions
@@ -115,14 +123,48 @@ export async function createContentGenerator(
  gcConfig: Config,
  isInitialAuth?: boolean,
 ): Promise<ContentGenerator> {
+  const version = process.env['CLI_VERSION'] || process.version;
+  const userAgent = `QwenCode/${version} (${process.platform}; ${process.arch})`;
+  const baseHeaders: Record<string, string> = {
+    'User-Agent': userAgent,
+  };
+
+  if (
+    config.authType === AuthType.LOGIN_WITH_GOOGLE ||
+    config.authType === AuthType.CLOUD_SHELL
+  ) {
+    const httpOptions = { headers: baseHeaders };
+    return new LoggingContentGenerator(
+      await createCodeAssistContentGenerator(
+        httpOptions,
+        config.authType,
+        gcConfig,
+      ),
+      gcConfig,
+    );
+  }
+
  if (
    config.authType === AuthType.USE_GEMINI ||
    config.authType === AuthType.USE_VERTEX_AI
  ) {
-    const { createGeminiContentGenerator } = await import(
-      './geminiContentGenerator/index.js'
-    );
-    return createGeminiContentGenerator(config, gcConfig);
+    let headers: Record<string, string> = { ...baseHeaders };
+    if (gcConfig?.getUsageStatisticsEnabled()) {
+      const installationManager = new InstallationManager();
+      const installationId = installationManager.getInstallationId();
+      headers = {
+        ...headers,
+        'x-gemini-api-privileged-user-id': `${installationId}`,
+      };
+    }
+    const httpOptions = { headers };
+
+    const googleGenAI = new GoogleGenAI({
+      apiKey: config.apiKey === '' ? undefined : config.apiKey,
+      vertexai: config.vertexai,
+      httpOptions,
+    });
+    return new LoggingContentGenerator(googleGenAI.models, gcConfig);
  }

  if (config.authType === AuthType.USE_OPENAI) {
--- a/packages/core/src/core/coreToolScheduler.test.ts
+++ b/packages/core/src/core/coreToolScheduler.test.ts
@@ -240,7 +240,7 @@ describe('CoreToolScheduler', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -318,7 +318,7 @@ describe('CoreToolScheduler', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -497,7 +497,7 @@ describe('CoreToolScheduler', () => {
        getExcludeTools: () => ['write_file', 'edit', 'run_shell_command'],
        getContentGeneratorConfig: () => ({
          model: 'test-model',
-          authType: 'gemini-api-key',
+          authType: 'oauth-personal',
        }),
        getShellExecutionConfig: () => ({
          terminalWidth: 90,
@@ -584,7 +584,7 @@ describe('CoreToolScheduler', () => {
        getExcludeTools: () => ['write_file', 'edit'], // Different excluded tools
        getContentGeneratorConfig: () => ({
          model: 'test-model',
-          authType: 'gemini-api-key',
+          authType: 'oauth-personal',
        }),
        getShellExecutionConfig: () => ({
          terminalWidth: 90,
@@ -674,7 +674,7 @@ describe('CoreToolScheduler with payload', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -1001,7 +1001,7 @@ describe('CoreToolScheduler edit cancellation', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -1108,7 +1108,7 @@ describe('CoreToolScheduler YOLO mode', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -1258,7 +1258,7 @@ describe('CoreToolScheduler cancellation during executing with live output', ()
      getApprovalMode: () => ApprovalMode.DEFAULT,
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getToolRegistry: () => mockToolRegistry,
      getShellExecutionConfig: () => ({
@@ -1350,7 +1350,7 @@ describe('CoreToolScheduler request queueing', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -1482,7 +1482,7 @@ describe('CoreToolScheduler request queueing', () => {
      getToolRegistry: () => toolRegistry,
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 80,
@@ -1586,7 +1586,7 @@ describe('CoreToolScheduler request queueing', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -1854,7 +1854,7 @@ describe('CoreToolScheduler Sequential Execution', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
@@ -1975,7 +1975,7 @@ describe('CoreToolScheduler Sequential Execution', () => {
      getAllowedTools: () => [],
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
--- a/packages/core/src/core/geminiChat.test.ts
+++ b/packages/core/src/core/geminiChat.test.ts
@@ -100,7 +100,6 @@ describe('GeminiChat', () => {
      countTokens: vi.fn(),
      embedContent: vi.fn(),
      batchEmbedContents: vi.fn(),
-      useSummarizedThinking: vi.fn().mockReturnValue(false),
    } as unknown as ContentGenerator;

    mockHandleFallback.mockClear();
@@ -112,7 +111,7 @@ describe('GeminiChat', () => {
      getUsageStatisticsEnabled: () => true,
      getDebugMode: () => false,
      getContentGeneratorConfig: vi.fn().mockReturnValue({
-        authType: 'gemini-api-key', // Ensure this is set for fallback tests
+        authType: 'oauth-personal', // Ensure this is set for fallback tests
        model: 'test-model',
      }),
      getModel: vi.fn().mockReturnValue('gemini-pro'),
@@ -719,99 +718,6 @@ describe('GeminiChat', () => {
        1,
      );
    });
-
-    it('should handle summarized thinking by conditionally including thoughts in history', async () => {
-      // Case 1: useSummarizedThinking is true -> thoughts NOT in history
-      vi.mocked(mockContentGenerator.useSummarizedThinking).mockReturnValue(
-        true,
-      );
-      const stream1 = (async function* () {
-        yield {
-          candidates: [
-            {
-              content: {
-                role: 'model',
-                parts: [{ thought: true, text: 'T1' }, { text: 'A1' }],
-              },
-              finishReason: 'STOP',
-            },
-          ],
-        } as unknown as GenerateContentResponse;
-      })();
-      vi.mocked(mockContentGenerator.generateContentStream).mockResolvedValue(
-        stream1,
-      );
-
-      const res1 = await chat.sendMessageStream('m1', { message: 'h1' }, 'p1');
-      for await (const _ of res1);
-
-      const history1 = chat.getHistory();
-      expect(history1[1].parts).toEqual([{ text: 'A1' }]);
-
-      // Case 2: useSummarizedThinking is false -> thoughts ARE in history
-      chat.clearHistory();
-      vi.mocked(mockContentGenerator.useSummarizedThinking).mockReturnValue(
-        false,
-      );
-      const stream2 = (async function* () {
-        yield {
-          candidates: [
-            {
-              content: {
-                role: 'model',
-                parts: [{ thought: true, text: 'T2' }, { text: 'A2' }],
-              },
-              finishReason: 'STOP',
-            },
-          ],
-        } as unknown as GenerateContentResponse;
-      })();
-      vi.mocked(mockContentGenerator.generateContentStream).mockResolvedValue(
-        stream2,
-      );
-
-      const res2 = await chat.sendMessageStream('m1', { message: 'h1' }, 'p2');
-      for await (const _ of res2);
-
-      const history2 = chat.getHistory();
-      expect(history2[1].parts).toEqual([
-        { text: 'T2', thought: true },
-        { text: 'A2' },
-      ]);
-    });
-
-    it('should keep parts with thoughtSignature when consolidating history', async () => {
-      const stream = (async function* () {
-        yield {
-          candidates: [
-            {
-              content: {
-                role: 'model',
-                parts: [
-                  {
-                    text: 'p1',
-                    thoughtSignature: 's1',
-                  } as unknown as { text: string; thoughtSignature: string },
-                ],
-              },
-              finishReason: 'STOP',
-            },
-          ],
-        } as unknown as GenerateContentResponse;
-      })();
-      vi.mocked(mockContentGenerator.generateContentStream).mockResolvedValue(
-        stream,
-      );
-
-      const res = await chat.sendMessageStream('m1', { message: 'h1' }, 'p1');
-      for await (const _ of res);
-
-      const history = chat.getHistory();
-      expect(history[1].parts![0]).toEqual({
-        text: 'p1',
-        thoughtSignature: 's1',
-      });
-    });
  });

  describe('addHistory', () => {
@@ -1476,7 +1382,7 @@ describe('GeminiChat', () => {
    });

    it('should call handleFallback with the specific failed model and retry if handler returns true', async () => {
-      const authType = AuthType.USE_GEMINI;
+      const authType = AuthType.LOGIN_WITH_GOOGLE;
      vi.mocked(mockConfig.getContentGeneratorConfig).mockReturnValue({
        model: 'test-model',
        authType,
@@ -1626,7 +1532,7 @@ describe('GeminiChat', () => {
  });

  describe('stripThoughtsFromHistory', () => {
-    it('should strip thoughts and thought signatures, and remove empty content objects', () => {
+    it('should strip thought signatures', () => {
      chat.setHistory([
        {
          role: 'user',
@@ -1638,15 +1544,10 @@ describe('GeminiChat', () => {
            { text: 'thinking...', thought: true },
            { text: 'hi' },
            {
-              text: 'hidden metadata',
-              thoughtSignature: 'abc',
-            } as unknown as { text: string; thoughtSignature: string },
+              functionCall: { name: 'test', args: {} },
+            },
          ],
        },
-        {
-          role: 'model',
-          parts: [{ text: 'only thinking', thought: true }],
-        },
      ]);

      chat.stripThoughtsFromHistory();
@@ -1658,7 +1559,7 @@ describe('GeminiChat', () => {
        },
        {
          role: 'model',
-          parts: [{ text: 'hi' }, { text: 'hidden metadata' }],
+          parts: [{ text: 'hi' }, { functionCall: { name: 'test', args: {} } }],
        },
      ]);
    });
--- a/packages/core/src/core/geminiChat.ts
+++ b/packages/core/src/core/geminiChat.ts
@@ -92,7 +92,6 @@ export function isValidNonThoughtTextPart(part: Part): boolean {
  return (
    typeof part.text === 'string' &&
    !part.thought &&
-    !part.thoughtSignature &&
    // Technically, the model should never generate parts that have text and
    //  any of these but we don't trust them so check anyways.
    !part.functionCall &&
@@ -110,24 +109,18 @@ function isValidContent(content: Content): boolean {
    if (part === undefined || Object.keys(part).length === 0) {
      return false;
    }
-    if (!isValidContentPart(part)) {
+    if (
+      !part.thought &&
+      part.text !== undefined &&
+      part.text === '' &&
+      part.functionCall === undefined
+    ) {
      return false;
    }
  }
  return true;
 }

-function isValidContentPart(part: Part): boolean {
-  const isInvalid =
-    !part.thought &&
-    !part.thoughtSignature &&
-    part.text !== undefined &&
-    part.text === '' &&
-    part.functionCall === undefined;
-
-  return !isInvalid;
-}
-
 /**
 * Validates the history contains the correct roles.
 *
@@ -455,29 +448,15 @@ export class GeminiChat {
        if (!content.parts) return content;

        // Filter out thought parts entirely
-        const filteredParts = content.parts
-          .filter(
-            (part) =>
-              !(
-                part &&
-                typeof part === 'object' &&
-                'thought' in part &&
-                part.thought
-              ),
-          )
-          .map((part) => {
-            if (
+        const filteredParts = content.parts.filter(
+          (part) =>
+            !(
              part &&
              typeof part === 'object' &&
-              'thoughtSignature' in part
-            ) {
-              const newPart = { ...part };
-              delete (newPart as { thoughtSignature?: string })
-                .thoughtSignature;
-              return newPart;
-            }
-            return part;
-          });
+              'thought' in part &&
+              part.thought
+            ),
+        );

        return {
          ...content,
@@ -559,15 +538,11 @@ export class GeminiChat {
      yield chunk; // Yield every chunk to the UI immediately.
    }

-    let thoughtText = '';
-    // Only include thoughts if not using summarized thinking.
-    if (!this.config.getContentGenerator().useSummarizedThinking()) {
-      thoughtText = allModelParts
-        .filter((part) => part.thought)
-        .map((part) => part.text)
-        .join('')
-        .trim();
-    }
+    const thoughtParts = allModelParts.filter((part) => part.thought);
+    const thoughtText = thoughtParts
+      .map((part) => part.text)
+      .join('')
+      .trim();

    const contentParts = allModelParts.filter((part) => !part.thought);
    const consolidatedHistoryParts: Part[] = [];
@@ -580,7 +555,7 @@ export class GeminiChat {
        isValidNonThoughtTextPart(part)
      ) {
        lastPart.text += part.text;
-      } else if (isValidContentPart(part)) {
+      } else {
        consolidatedHistoryParts.push(part);
      }
    }
--- a/packages/core/src/core/geminiContentGenerator/geminiContentGenerator.test.ts
+++ b/packages/core/src/core/geminiContentGenerator/geminiContentGenerator.test.ts
@@ -1,173 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { GeminiContentGenerator } from './geminiContentGenerator.js';
-import { GoogleGenAI } from '@google/genai';
-
-vi.mock('@google/genai', () => {
-  const mockGenerateContent = vi.fn();
-  const mockGenerateContentStream = vi.fn();
-  const mockCountTokens = vi.fn();
-  const mockEmbedContent = vi.fn();
-
-  return {
-    GoogleGenAI: vi.fn().mockImplementation(() => ({
-      models: {
-        generateContent: mockGenerateContent,
-        generateContentStream: mockGenerateContentStream,
-        countTokens: mockCountTokens,
-        embedContent: mockEmbedContent,
-      },
-    })),
-  };
-});
-
-describe('GeminiContentGenerator', () => {
-  let generator: GeminiContentGenerator;
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  let mockGoogleGenAI: any;
-
-  beforeEach(() => {
-    vi.clearAllMocks();
-    generator = new GeminiContentGenerator({
-      apiKey: 'test-api-key',
-    });
-    mockGoogleGenAI = vi.mocked(GoogleGenAI).mock.results[0].value;
-  });
-
-  it('should call generateContent on the underlying model', async () => {
-    const request = { model: 'gemini-1.5-flash', contents: [] };
-    const expectedResponse = { responseId: 'test-id' };
-    mockGoogleGenAI.models.generateContent.mockResolvedValue(expectedResponse);
-
-    const response = await generator.generateContent(request, 'prompt-id');
-
-    expect(mockGoogleGenAI.models.generateContent).toHaveBeenCalledWith(
-      expect.objectContaining({
-        ...request,
-        config: expect.objectContaining({
-          temperature: 1,
-          topP: 0.95,
-          thinkingConfig: {
-            includeThoughts: true,
-            thinkingLevel: 'THINKING_LEVEL_UNSPECIFIED',
-          },
-        }),
-      }),
-    );
-    expect(response).toBe(expectedResponse);
-  });
-
-  it('should call generateContentStream on the underlying model', async () => {
-    const request = { model: 'gemini-1.5-flash', contents: [] };
-    const mockStream = (async function* () {
-      yield { responseId: '1' };
-    })();
-    mockGoogleGenAI.models.generateContentStream.mockResolvedValue(mockStream);
-
-    const stream = await generator.generateContentStream(request, 'prompt-id');
-
-    expect(mockGoogleGenAI.models.generateContentStream).toHaveBeenCalledWith(
-      expect.objectContaining({
-        ...request,
-        config: expect.objectContaining({
-          temperature: 1,
-          topP: 0.95,
-          thinkingConfig: {
-            includeThoughts: true,
-            thinkingLevel: 'THINKING_LEVEL_UNSPECIFIED',
-          },
-        }),
-      }),
-    );
-    expect(stream).toBe(mockStream);
-  });
-
-  it('should call countTokens on the underlying model', async () => {
-    const request = { model: 'gemini-1.5-flash', contents: [] };
-    const expectedResponse = { totalTokens: 10 };
-    mockGoogleGenAI.models.countTokens.mockResolvedValue(expectedResponse);
-
-    const response = await generator.countTokens(request);
-
-    expect(mockGoogleGenAI.models.countTokens).toHaveBeenCalledWith(request);
-    expect(response).toBe(expectedResponse);
-  });
-
-  it('should call embedContent on the underlying model', async () => {
-    const request = { model: 'embedding-model', contents: [] };
-    const expectedResponse = { embeddings: [] };
-    mockGoogleGenAI.models.embedContent.mockResolvedValue(expectedResponse);
-
-    const response = await generator.embedContent(request);
-
-    expect(mockGoogleGenAI.models.embedContent).toHaveBeenCalledWith(request);
-    expect(response).toBe(expectedResponse);
-  });
-
-  it('should prioritize contentGeneratorConfig samplingParams over request config', async () => {
-    const generatorWithParams = new GeminiContentGenerator({ apiKey: 'test' }, {
-      model: 'gemini-1.5-flash',
-      samplingParams: {
-        temperature: 0.1,
-        top_p: 0.2,
-      },
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    } as any);
-
-    const request = {
-      model: 'gemini-1.5-flash',
-      contents: [],
-      config: {
-        temperature: 0.9,
-        topP: 0.9,
-      },
-    };
-
-    await generatorWithParams.generateContent(request, 'prompt-id');
-
-    expect(mockGoogleGenAI.models.generateContent).toHaveBeenCalledWith(
-      expect.objectContaining({
-        config: expect.objectContaining({
-          temperature: 0.1,
-          topP: 0.2,
-        }),
-      }),
-    );
-  });
-
-  it('should map reasoning effort to thinkingConfig', async () => {
-    const generatorWithReasoning = new GeminiContentGenerator(
-      { apiKey: 'test' },
-      {
-        model: 'gemini-2.5-pro',
-        reasoning: {
-          effort: 'high',
-        },
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      } as any,
-    );
-
-    const request = {
-      model: 'gemini-2.5-pro',
-      contents: [],
-    };
-
-    await generatorWithReasoning.generateContent(request, 'prompt-id');
-
-    expect(mockGoogleGenAI.models.generateContent).toHaveBeenCalledWith(
-      expect.objectContaining({
-        config: expect.objectContaining({
-          thinkingConfig: {
-            includeThoughts: true,
-            thinkingLevel: 'HIGH',
-          },
-        }),
-      }),
-    );
-  });
-});
--- a/packages/core/src/core/geminiContentGenerator/geminiContentGenerator.ts
+++ b/packages/core/src/core/geminiContentGenerator/geminiContentGenerator.ts
@@ -1,144 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-import type {
-  CountTokensParameters,
-  CountTokensResponse,
-  EmbedContentParameters,
-  EmbedContentResponse,
-  GenerateContentParameters,
-  GenerateContentResponse,
-  GenerateContentConfig,
-  ThinkingLevel,
-} from '@google/genai';
-import { GoogleGenAI } from '@google/genai';
-import type {
-  ContentGenerator,
-  ContentGeneratorConfig,
-} from '../contentGenerator.js';
-
-/**
- * A wrapper for GoogleGenAI that implements the ContentGenerator interface.
- */
-export class GeminiContentGenerator implements ContentGenerator {
-  private readonly googleGenAI: GoogleGenAI;
-  private readonly contentGeneratorConfig?: ContentGeneratorConfig;
-
-  constructor(
-    options: {
-      apiKey?: string;
-      vertexai?: boolean;
-      httpOptions?: { headers: Record<string, string> };
-    },
-    contentGeneratorConfig?: ContentGeneratorConfig,
-  ) {
-    this.googleGenAI = new GoogleGenAI(options);
-    this.contentGeneratorConfig = contentGeneratorConfig;
-  }
-
-  private buildSamplingParameters(
-    request: GenerateContentParameters,
-  ): GenerateContentConfig {
-    const configSamplingParams = this.contentGeneratorConfig?.samplingParams;
-    const requestConfig = request.config || {};
-
-    // Helper function to get parameter value with priority: config > request > default
-    const getParameterValue = <T>(
-      configValue: T | undefined,
-      requestKey: keyof GenerateContentConfig,
-      defaultValue?: T,
-    ): T | undefined => {
-      const requestValue = requestConfig[requestKey] as T | undefined;
-
-      if (configValue !== undefined) return configValue;
-      if (requestValue !== undefined) return requestValue;
-      return defaultValue;
-    };
-
-    return {
-      ...requestConfig,
-      temperature: getParameterValue<number>(
-        configSamplingParams?.temperature,
-        'temperature',
-        1,
-      ),
-      topP: getParameterValue<number>(
-        configSamplingParams?.top_p,
-        'topP',
-        0.95,
-      ),
-      topK: getParameterValue<number>(configSamplingParams?.top_k, 'topK', 64),
-      maxOutputTokens: getParameterValue<number>(
-        configSamplingParams?.max_tokens,
-        'maxOutputTokens',
-      ),
-      presencePenalty: getParameterValue<number>(
-        configSamplingParams?.presence_penalty,
-        'presencePenalty',
-      ),
-      frequencyPenalty: getParameterValue<number>(
-        configSamplingParams?.frequency_penalty,
-        'frequencyPenalty',
-      ),
-      thinkingConfig: getParameterValue(
-        this.contentGeneratorConfig?.reasoning
-          ? {
-              includeThoughts: true,
-              thinkingLevel: (this.contentGeneratorConfig.reasoning.effort ===
-              'low'
-                ? 'LOW'
-                : this.contentGeneratorConfig.reasoning.effort === 'high'
-                  ? 'HIGH'
-                  : 'THINKING_LEVEL_UNSPECIFIED') as ThinkingLevel,
-            }
-          : undefined,
-        'thinkingConfig',
-        {
-          includeThoughts: true,
-          thinkingLevel: 'THINKING_LEVEL_UNSPECIFIED' as ThinkingLevel,
-        },
-      ),
-    };
-  }
-
-  async generateContent(
-    request: GenerateContentParameters,
-    _userPromptId: string,
-  ): Promise<GenerateContentResponse> {
-    const finalRequest = {
-      ...request,
-      config: this.buildSamplingParameters(request),
-    };
-    return this.googleGenAI.models.generateContent(finalRequest);
-  }
-
-  async generateContentStream(
-    request: GenerateContentParameters,
-    _userPromptId: string,
-  ): Promise<AsyncGenerator<GenerateContentResponse>> {
-    const finalRequest = {
-      ...request,
-      config: this.buildSamplingParameters(request),
-    };
-    return this.googleGenAI.models.generateContentStream(finalRequest);
-  }
-
-  async countTokens(
-    request: CountTokensParameters,
-  ): Promise<CountTokensResponse> {
-    return this.googleGenAI.models.countTokens(request);
-  }
-
-  async embedContent(
-    request: EmbedContentParameters,
-  ): Promise<EmbedContentResponse> {
-    return this.googleGenAI.models.embedContent(request);
-  }
-
-  useSummarizedThinking(): boolean {
-    return true;
-  }
-}
--- a/packages/core/src/core/geminiContentGenerator/index.test.ts
+++ b/packages/core/src/core/geminiContentGenerator/index.test.ts
@@ -1,47 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { createGeminiContentGenerator } from './index.js';
-import { GeminiContentGenerator } from './geminiContentGenerator.js';
-import { LoggingContentGenerator } from './loggingContentGenerator.js';
-import type { Config } from '../../config/config.js';
-import { AuthType } from '../contentGenerator.js';
-
-vi.mock('./geminiContentGenerator.js', () => ({
-  GeminiContentGenerator: vi.fn().mockImplementation(() => ({})),
-}));
-
-vi.mock('./loggingContentGenerator.js', () => ({
-  LoggingContentGenerator: vi.fn().mockImplementation((wrapped) => wrapped),
-}));
-
-describe('createGeminiContentGenerator', () => {
-  let mockConfig: Config;
-
-  beforeEach(() => {
-    vi.clearAllMocks();
-    mockConfig = {
-      getUsageStatisticsEnabled: vi.fn().mockReturnValue(false),
-      getContentGeneratorConfig: vi.fn().mockReturnValue({}),
-      getCliVersion: vi.fn().mockReturnValue('1.0.0'),
-    } as unknown as Config;
-  });
-
-  it('should create a GeminiContentGenerator wrapped in LoggingContentGenerator', () => {
-    const config = {
-      model: 'gemini-1.5-flash',
-      apiKey: 'test-key',
-      authType: AuthType.USE_GEMINI,
-    };
-
-    const generator = createGeminiContentGenerator(config, mockConfig);
-
-    expect(GeminiContentGenerator).toHaveBeenCalled();
-    expect(LoggingContentGenerator).toHaveBeenCalled();
-    expect(generator).toBeDefined();
-  });
-});
--- a/packages/core/src/core/geminiContentGenerator/index.ts
+++ b/packages/core/src/core/geminiContentGenerator/index.ts
@@ -1,55 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-import { GeminiContentGenerator } from './geminiContentGenerator.js';
-import type {
-  ContentGenerator,
-  ContentGeneratorConfig,
-} from '../contentGenerator.js';
-import type { Config } from '../../config/config.js';
-import { InstallationManager } from '../../utils/installationManager.js';
-import { LoggingContentGenerator } from './loggingContentGenerator.js';
-
-export { GeminiContentGenerator } from './geminiContentGenerator.js';
-export { LoggingContentGenerator } from './loggingContentGenerator.js';
-
-/**
- * Create a Gemini content generator.
- */
-export function createGeminiContentGenerator(
-  config: ContentGeneratorConfig,
-  gcConfig: Config,
-): ContentGenerator {
-  const version = process.env['CLI_VERSION'] || process.version;
-  const userAgent =
-    config.userAgent ||
-    `QwenCode/${version} (${process.platform}; ${process.arch})`;
-  const baseHeaders: Record<string, string> = {
-    'User-Agent': userAgent,
-  };
-
-  let headers: Record<string, string> = { ...baseHeaders };
-  if (gcConfig?.getUsageStatisticsEnabled()) {
-    const installationManager = new InstallationManager();
-    const installationId = installationManager.getInstallationId();
-    headers = {
-      ...headers,
-      'x-gemini-api-privileged-user-id': `${installationId}`,
-    };
-  }
-  const httpOptions = { headers };
-
-  const geminiContentGenerator = new GeminiContentGenerator(
-    {
-      apiKey: config.apiKey === '' ? undefined : config.apiKey,
-      vertexai: config.vertexai,
-      httpOptions,
-    },
-    config,
-  );
-
-  return new LoggingContentGenerator(geminiContentGenerator, gcConfig);
-}
--- a/packages/core/src/core/geminiContentGenerator/loggingContentGenerator.ts
+++ b/packages/core/src/core/geminiContentGenerator/loggingContentGenerator.ts
@@ -13,24 +13,21 @@ import type {
  GenerateContentParameters,
  GenerateContentResponseUsageMetadata,
  GenerateContentResponse,
-  ContentListUnion,
-  ContentUnion,
-  Part,
-  PartUnion,
 } from '@google/genai';
 import {
  ApiRequestEvent,
  ApiResponseEvent,
  ApiErrorEvent,
-} from '../../telemetry/types.js';
-import type { Config } from '../../config/config.js';
+} from '../telemetry/types.js';
+import type { Config } from '../config/config.js';
 import {
  logApiError,
  logApiRequest,
  logApiResponse,
-} from '../../telemetry/loggers.js';
-import type { ContentGenerator } from '../contentGenerator.js';
-import { isStructuredError } from '../../utils/quotaErrorDetection.js';
+} from '../telemetry/loggers.js';
+import type { ContentGenerator } from './contentGenerator.js';
+import { toContents } from '../code_assist/converter.js';
+import { isStructuredError } from '../utils/quotaErrorDetection.js';

 interface StructuredError {
  status: number;
@@ -115,7 +112,7 @@ export class LoggingContentGenerator implements ContentGenerator {
    userPromptId: string,
  ): Promise<GenerateContentResponse> {
    const startTime = Date.now();
-    this.logApiRequest(this.toContents(req.contents), req.model, userPromptId);
+    this.logApiRequest(toContents(req.contents), req.model, userPromptId);
    try {
      const response = await this.wrapped.generateContent(req, userPromptId);
      const durationMs = Date.now() - startTime;
@@ -140,7 +137,7 @@ export class LoggingContentGenerator implements ContentGenerator {
    userPromptId: string,
  ): Promise<AsyncGenerator<GenerateContentResponse>> {
    const startTime = Date.now();
-    this.logApiRequest(this.toContents(req.contents), req.model, userPromptId);
+    this.logApiRequest(toContents(req.contents), req.model, userPromptId);

    let stream: AsyncGenerator<GenerateContentResponse>;
    try {
@@ -208,95 +205,4 @@ export class LoggingContentGenerator implements ContentGenerator {
  ): Promise<EmbedContentResponse> {
    return this.wrapped.embedContent(req);
  }
-
-  useSummarizedThinking(): boolean {
-    return this.wrapped.useSummarizedThinking();
-  }
-
-  private toContents(contents: ContentListUnion): Content[] {
-    if (Array.isArray(contents)) {
-      // it's a Content[] or a PartsUnion[]
-      return contents.map((c) => this.toContent(c));
-    }
-    // it's a Content or a PartsUnion
-    return [this.toContent(contents)];
-  }
-
-  private toContent(content: ContentUnion): Content {
-    if (Array.isArray(content)) {
-      // it's a PartsUnion[]
-      return {
-        role: 'user',
-        parts: this.toParts(content),
-      };
-    }
-    if (typeof content === 'string') {
-      // it's a string
-      return {
-        role: 'user',
-        parts: [{ text: content }],
-      };
-    }
-    if ('parts' in content) {
-      // it's a Content - process parts to handle thought filtering
-      return {
-        ...content,
-        parts: content.parts
-          ? this.toParts(content.parts.filter((p) => p != null))
-          : [],
-      };
-    }
-    // it's a Part
-    return {
-      role: 'user',
-      parts: [this.toPart(content as Part)],
-    };
-  }
-
-  private toParts(parts: PartUnion[]): Part[] {
-    return parts.map((p) => this.toPart(p));
-  }
-
-  private toPart(part: PartUnion): Part {
-    if (typeof part === 'string') {
-      // it's a string
-      return { text: part };
-    }
-
-    // Handle thought parts for CountToken API compatibility
-    // The CountToken API expects parts to have certain required "oneof" fields initialized,
-    // but thought parts don't conform to this schema and cause API failures
-    if ('thought' in part && part.thought) {
-      const thoughtText = `[Thought: ${part.thought}]`;
-
-      const newPart = { ...part };
-      delete (newPart as Record<string, unknown>)['thought'];
-
-      const hasApiContent =
-        'functionCall' in newPart ||
-        'functionResponse' in newPart ||
-        'inlineData' in newPart ||
-        'fileData' in newPart;
-
-      if (hasApiContent) {
-        // It's a functionCall or other non-text part. Just strip the thought.
-        return newPart;
-      }
-
-      // If no other valid API content, this must be a text part.
-      // Combine existing text (if any) with the thought, preserving other properties.
-      const text = (newPart as { text?: unknown }).text;
-      const existingText = text ? String(text) : '';
-      const combinedText = existingText
-        ? `${existingText}\n${thoughtText}`
-        : thoughtText;
-
-      return {
-        ...newPart,
-        text: combinedText,
-      };
-    }
-
-    return part;
-  }
 }
--- a/packages/core/src/core/nonInteractiveToolExecutor.test.ts
+++ b/packages/core/src/core/nonInteractiveToolExecutor.test.ts
@@ -47,7 +47,7 @@ describe('executeToolCall', () => {
      getDebugMode: () => false,
      getContentGeneratorConfig: () => ({
        model: 'test-model',
-        authType: 'gemini-api-key',
+        authType: 'oauth-personal',
      }),
      getShellExecutionConfig: () => ({
        terminalWidth: 90,
--- a/packages/core/src/core/openaiContentGenerator/openaiContentGenerator.test.ts
+++ b/packages/core/src/core/openaiContentGenerator/openaiContentGenerator.test.ts
@@ -99,7 +99,6 @@ describe('OpenAIContentGenerator (Refactored)', () => {
        },
      } as unknown as OpenAI),
      buildRequest: vi.fn().mockImplementation((req) => req),
-      getDefaultGenerationConfig: vi.fn().mockReturnValue({}),
    };

    generator = new OpenAIContentGenerator(
@@ -212,7 +211,6 @@ describe('OpenAIContentGenerator (Refactored)', () => {
          },
        } as unknown as OpenAI),
        buildRequest: vi.fn().mockImplementation((req) => req),
-        getDefaultGenerationConfig: vi.fn().mockReturnValue({}),
      };

      const testGenerator = new TestGenerator(
@@ -279,7 +277,6 @@ describe('OpenAIContentGenerator (Refactored)', () => {
          },
        } as unknown as OpenAI),
        buildRequest: vi.fn().mockImplementation((req) => req),
-        getDefaultGenerationConfig: vi.fn().mockReturnValue({}),
      };

      const testGenerator = new TestGenerator(
--- a/packages/core/src/core/openaiContentGenerator/openaiContentGenerator.ts
+++ b/packages/core/src/core/openaiContentGenerator/openaiContentGenerator.ts
@@ -154,8 +154,4 @@ export class OpenAIContentGenerator implements ContentGenerator {
      );
    }
  }
-
-  useSummarizedThinking(): boolean {
-    return false;
-  }
 }
--- a/packages/core/src/core/openaiContentGenerator/pipeline.test.ts
+++ b/packages/core/src/core/openaiContentGenerator/pipeline.test.ts
@@ -60,7 +60,6 @@ describe('ContentGenerationPipeline', () => {
      buildClient: vi.fn().mockReturnValue(mockClient),
      buildRequest: vi.fn().mockImplementation((req) => req),
      buildHeaders: vi.fn().mockReturnValue({}),
-      getDefaultGenerationConfig: vi.fn().mockReturnValue({}),
    };

    // Mock telemetry service
--- a/packages/core/src/core/openaiContentGenerator/pipeline.ts
+++ b/packages/core/src/core/openaiContentGenerator/pipeline.ts
@@ -283,22 +283,16 @@ export class ContentGenerationPipeline {
  private buildSamplingParameters(
    request: GenerateContentParameters,
  ): Record<string, unknown> {
-    const defaultSamplingParams =
-      this.config.provider.getDefaultGenerationConfig();
    const configSamplingParams = this.contentGeneratorConfig.samplingParams;

    // Helper function to get parameter value with priority: config > request > default
    const getParameterValue = <T>(
      configKey: keyof NonNullable<typeof configSamplingParams>,
-      requestKey?: keyof NonNullable<typeof request.config>,
+      requestKey: keyof NonNullable<typeof request.config>,
+      defaultValue?: T,
    ): T | undefined => {
      const configValue = configSamplingParams?.[configKey] as T | undefined;
-      const requestValue = requestKey
-        ? (request.config?.[requestKey] as T | undefined)
-        : undefined;
-      const defaultValue = requestKey
-        ? (defaultSamplingParams[requestKey] as T)
-        : undefined;
+      const requestValue = request.config?.[requestKey] as T | undefined;

      if (configValue !== undefined) return configValue;
      if (requestValue !== undefined) return requestValue;
@@ -310,8 +304,12 @@ export class ContentGenerationPipeline {
      key: string,
      configKey: keyof NonNullable<typeof configSamplingParams>,
      requestKey?: keyof NonNullable<typeof request.config>,
-    ): Record<string, T | undefined> => {
-      const value = getParameterValue<T>(configKey, requestKey);
+      defaultValue?: T,
+    ): Record<string, T> | Record<string, never> => {
+      const value = requestKey
+        ? getParameterValue(configKey, requestKey, defaultValue)
+        : ((configSamplingParams?.[configKey] as T | undefined) ??
+          defaultValue);

      return value !== undefined ? { [key]: value } : {};
    };
@@ -325,18 +323,10 @@ export class ContentGenerationPipeline {
      ...addParameterIfDefined('max_tokens', 'max_tokens', 'maxOutputTokens'),

      // Config-only parameters (no request fallback)
-      ...addParameterIfDefined('top_k', 'top_k', 'topK'),
+      ...addParameterIfDefined('top_k', 'top_k'),
      ...addParameterIfDefined('repetition_penalty', 'repetition_penalty'),
-      ...addParameterIfDefined(
-        'presence_penalty',
-        'presence_penalty',
-        'presencePenalty',
-      ),
-      ...addParameterIfDefined(
-        'frequency_penalty',
-        'frequency_penalty',
-        'frequencyPenalty',
-      ),
+      ...addParameterIfDefined('presence_penalty', 'presence_penalty'),
+      ...addParameterIfDefined('frequency_penalty', 'frequency_penalty'),
    };

    return params;
--- a/packages/core/src/core/openaiContentGenerator/provider/dashscope.ts
+++ b/packages/core/src/core/openaiContentGenerator/provider/dashscope.ts
@@ -1,5 +1,4 @@
 import OpenAI from 'openai';
-import type { GenerateContentConfig } from '@google/genai';
 import type { Config } from '../../../config/config.js';
 import type { ContentGeneratorConfig } from '../../contentGenerator.js';
 import { AuthType } from '../../contentGenerator.js';
@@ -142,14 +141,6 @@ export class DashScopeOpenAICompatibleProvider
    };
  }

-  getDefaultGenerationConfig(): GenerateContentConfig {
-    return {
-      temperature: 0.7,
-      topP: 0.8,
-      topK: 20,
-    };
-  }
-
  /**
   * Add cache control flag to specified message(s) for DashScope providers
   */
--- a/packages/core/src/core/openaiContentGenerator/provider/deepseek.ts
+++ b/packages/core/src/core/openaiContentGenerator/provider/deepseek.ts
@@ -8,7 +8,6 @@ import type OpenAI from 'openai';
 import type { Config } from '../../../config/config.js';
 import type { ContentGeneratorConfig } from '../../contentGenerator.js';
 import { DefaultOpenAICompatibleProvider } from './default.js';
-import type { GenerateContentConfig } from '@google/genai';

 export class DeepSeekOpenAICompatibleProvider extends DefaultOpenAICompatibleProvider {
  constructor(
@@ -77,10 +76,4 @@ export class DeepSeekOpenAICompatibleProvider extends DefaultOpenAICompatiblePro
      messages,
    };
  }
-
-  override getDefaultGenerationConfig(): GenerateContentConfig {
-    return {
-      temperature: 0,
-    };
-  }
 }
--- a/packages/core/src/core/openaiContentGenerator/provider/default.ts
+++ b/packages/core/src/core/openaiContentGenerator/provider/default.ts
@@ -1,5 +1,4 @@
 import OpenAI from 'openai';
-import type { GenerateContentConfig } from '@google/genai';
 import type { Config } from '../../../config/config.js';
 import type { ContentGeneratorConfig } from '../../contentGenerator.js';
 import { DEFAULT_TIMEOUT, DEFAULT_MAX_RETRIES } from '../constants.js';
@@ -56,10 +55,4 @@ export class DefaultOpenAICompatibleProvider
      ...request, // Preserve all original parameters including sampling params
    };
  }
-
-  getDefaultGenerationConfig(): GenerateContentConfig {
-    return {
-      topP: 0.95,
-    };
-  }
 }
--- a/packages/core/src/core/openaiContentGenerator/provider/types.ts
+++ b/packages/core/src/core/openaiContentGenerator/provider/types.ts
@@ -1,4 +1,3 @@
-import type { GenerateContentConfig } from '@google/genai';
 import type OpenAI from 'openai';

 // Extended types to support cache_control for DashScope
@@ -23,7 +22,6 @@ export interface OpenAICompatibleProvider {
    request: OpenAI.Chat.ChatCompletionCreateParams,
    userPromptId: string,
  ): OpenAI.Chat.ChatCompletionCreateParams;
-  getDefaultGenerationConfig(): GenerateContentConfig;
 }

 export type DashScopeRequestMetadata = {
--- a/packages/core/src/core/turn.test.ts
+++ b/packages/core/src/core/turn.test.ts
@@ -36,6 +36,13 @@ vi.mock('../utils/errorReporting', () => ({
  reportError: vi.fn(),
 }));

+// Use the actual implementation from partUtils now that it's provided.
+vi.mock('../utils/generateContentResponseUtilities', () => ({
+  getResponseText: (resp: GenerateContentResponse) =>
+    resp.candidates?.[0]?.content?.parts?.map((part) => part.text).join('') ||
+    undefined,
+}));
+
 describe('Turn', () => {
  let turn: Turn;
  // Define a type for the mocked Chat instance for clarity
@@ -149,7 +156,6 @@ describe('Turn', () => {
          type: GeminiEventType.Thought,
          value: { subject: '', description: 'reasoning...' },
        },
-        { type: GeminiEventType.Content, value: 'final answer' },
      ]);
    });

--- a/packages/core/src/core/turn.ts
+++ b/packages/core/src/core/turn.ts
@@ -27,11 +27,7 @@ import {
  toFriendlyError,
 } from '../utils/errors.js';
 import type { GeminiChat } from './geminiChat.js';
-import {
-  getThoughtText,
-  parseThought,
-  type ThoughtSummary,
-} from '../utils/thoughtUtils.js';
+import { getThoughtText, type ThoughtSummary } from '../utils/thoughtUtils.js';

 // Define a structure for tools passed to the server
 export interface ServerTool {
@@ -270,12 +266,13 @@ export class Turn {
          this.currentResponseId = resp.responseId;
        }

-        const thoughtText = getThoughtText(resp);
-        if (thoughtText) {
+        const thoughtPart = getThoughtText(resp);
+        if (thoughtPart) {
          yield {
            type: GeminiEventType.Thought,
-            value: parseThought(thoughtText),
+            value: { subject: '', description: thoughtPart },
          };
+          continue;
        }

        const text = getResponseText(resp);
--- a/packages/core/src/fallback/handler.test.ts
+++ b/packages/core/src/fallback/handler.test.ts
@@ -4,10 +4,36 @@
 * SPDX-License-Identifier: Apache-2.0
 */

-import { describe, it, expect, vi, beforeEach } from 'vitest';
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  type Mock,
+  type MockInstance,
+  afterEach,
+} from 'vitest';
 import { handleFallback } from './handler.js';
 import type { Config } from '../config/config.js';
 import { AuthType } from '../core/contentGenerator.js';
+import {
+  DEFAULT_GEMINI_FLASH_MODEL,
+  DEFAULT_GEMINI_MODEL,
+} from '../config/models.js';
+import { logFlashFallback } from '../telemetry/index.js';
+import type { FallbackModelHandler } from './types.js';
+
+// Mock the telemetry logger and event class
+vi.mock('../telemetry/index.js', () => ({
+  logFlashFallback: vi.fn(),
+  FlashFallbackEvent: class {},
+}));
+
+const MOCK_PRO_MODEL = DEFAULT_GEMINI_MODEL;
+const FALLBACK_MODEL = DEFAULT_GEMINI_FLASH_MODEL;
+const AUTH_OAUTH = AuthType.LOGIN_WITH_GOOGLE;
+const AUTH_API_KEY = AuthType.USE_GEMINI;

 const createMockConfig = (overrides: Partial<Config> = {}): Config =>
  ({
@@ -19,28 +45,174 @@ const createMockConfig = (overrides: Partial<Config> = {}): Config =>

 describe('handleFallback', () => {
  let mockConfig: Config;
+  let mockHandler: Mock<FallbackModelHandler>;
+  let consoleErrorSpy: MockInstance;

  beforeEach(() => {
    vi.clearAllMocks();
-    mockConfig = createMockConfig();
+    mockHandler = vi.fn();
+    // Default setup: OAuth user, Pro model failed, handler injected
+    mockConfig = createMockConfig({
+      fallbackModelHandler: mockHandler,
+    });
+    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
  });

-  it('should return null for unknown auth types', async () => {
+  afterEach(() => {
+    consoleErrorSpy.mockRestore();
+  });
+
+  it('should return null immediately if authType is not OAuth', async () => {
    const result = await handleFallback(
      mockConfig,
-      'test-model',
-      'unknown-auth',
+      MOCK_PRO_MODEL,
+      AUTH_API_KEY,
+    );
+    expect(result).toBeNull();
+    expect(mockHandler).not.toHaveBeenCalled();
+    expect(mockConfig.setFallbackMode).not.toHaveBeenCalled();
+  });
+
+  it('should return null if the failed model is already the fallback model', async () => {
+    const result = await handleFallback(
+      mockConfig,
+      FALLBACK_MODEL, // Failed model is Flash
+      AUTH_OAUTH,
+    );
+    expect(result).toBeNull();
+    expect(mockHandler).not.toHaveBeenCalled();
+  });
+
+  it('should return null if no fallbackHandler is injected in config', async () => {
+    const configWithoutHandler = createMockConfig({
+      fallbackModelHandler: undefined,
+    });
+    const result = await handleFallback(
+      configWithoutHandler,
+      MOCK_PRO_MODEL,
+      AUTH_OAUTH,
    );
    expect(result).toBeNull();
  });

-  it('should handle Qwen OAuth error', async () => {
-    const result = await handleFallback(
-      mockConfig,
-      'test-model',
-      AuthType.QWEN_OAUTH,
-      new Error('unauthorized'),
+  describe('when handler returns "retry"', () => {
+    it('should activate fallback mode, log telemetry, and return true', async () => {
+      mockHandler.mockResolvedValue('retry');
+
+      const result = await handleFallback(
+        mockConfig,
+        MOCK_PRO_MODEL,
+        AUTH_OAUTH,
+      );
+
+      expect(result).toBe(true);
+      expect(mockConfig.setFallbackMode).toHaveBeenCalledWith(true);
+      expect(logFlashFallback).toHaveBeenCalled();
+    });
+  });
+
+  describe('when handler returns "stop"', () => {
+    it('should activate fallback mode, log telemetry, and return false', async () => {
+      mockHandler.mockResolvedValue('stop');
+
+      const result = await handleFallback(
+        mockConfig,
+        MOCK_PRO_MODEL,
+        AUTH_OAUTH,
+      );
+
+      expect(result).toBe(false);
+      expect(mockConfig.setFallbackMode).toHaveBeenCalledWith(true);
+      expect(logFlashFallback).toHaveBeenCalled();
+    });
+  });
+
+  describe('when handler returns "auth"', () => {
+    it('should NOT activate fallback mode and return false', async () => {
+      mockHandler.mockResolvedValue('auth');
+
+      const result = await handleFallback(
+        mockConfig,
+        MOCK_PRO_MODEL,
+        AUTH_OAUTH,
+      );
+
+      expect(result).toBe(false);
+      expect(mockConfig.setFallbackMode).not.toHaveBeenCalled();
+      expect(logFlashFallback).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('when handler returns an unexpected value', () => {
+    it('should log an error and return null', async () => {
+      mockHandler.mockResolvedValue(null);
+
+      const result = await handleFallback(
+        mockConfig,
+        MOCK_PRO_MODEL,
+        AUTH_OAUTH,
+      );
+
+      expect(result).toBeNull();
+      expect(consoleErrorSpy).toHaveBeenCalledWith(
+        'Fallback UI handler failed:',
+        new Error(
+          'Unexpected fallback intent received from fallbackModelHandler: "null"',
+        ),
+      );
+      expect(mockConfig.setFallbackMode).not.toHaveBeenCalled();
+    });
+  });
+
+  it('should pass the correct context (failedModel, fallbackModel, error) to the handler', async () => {
+    const mockError = new Error('Quota Exceeded');
+    mockHandler.mockResolvedValue('retry');
+
+    await handleFallback(mockConfig, MOCK_PRO_MODEL, AUTH_OAUTH, mockError);
+
+    expect(mockHandler).toHaveBeenCalledWith(
+      MOCK_PRO_MODEL,
+      FALLBACK_MODEL,
+      mockError,
    );
+  });
+
+  it('should not call setFallbackMode or log telemetry if already in fallback mode', async () => {
+    // Setup config where fallback mode is already active
+    const activeFallbackConfig = createMockConfig({
+      fallbackModelHandler: mockHandler,
+      isInFallbackMode: vi.fn(() => true), // Already active
+      setFallbackMode: vi.fn(),
+    });
+
+    mockHandler.mockResolvedValue('retry');
+
+    const result = await handleFallback(
+      activeFallbackConfig,
+      MOCK_PRO_MODEL,
+      AUTH_OAUTH,
+    );
+
+    // Should still return true to allow the retry (which will use the active fallback mode)
+    expect(result).toBe(true);
+    // Should still consult the handler
+    expect(mockHandler).toHaveBeenCalled();
+    // But should not mutate state or log telemetry again
+    expect(activeFallbackConfig.setFallbackMode).not.toHaveBeenCalled();
+    expect(logFlashFallback).not.toHaveBeenCalled();
+  });
+
+  it('should catch errors from the handler, log an error, and return null', async () => {
+    const handlerError = new Error('UI interaction failed');
+    mockHandler.mockRejectedValue(handlerError);
+
+    const result = await handleFallback(mockConfig, MOCK_PRO_MODEL, AUTH_OAUTH);
+
    expect(result).toBeNull();
+    expect(consoleErrorSpy).toHaveBeenCalledWith(
+      'Fallback UI handler failed:',
+      handlerError,
+    );
+    expect(mockConfig.setFallbackMode).not.toHaveBeenCalled();
  });
 });
--- a/packages/core/src/fallback/handler.ts
+++ b/packages/core/src/fallback/handler.ts
@@ -6,6 +6,8 @@

 import type { Config } from '../config/config.js';
 import { AuthType } from '../core/contentGenerator.js';
+import { DEFAULT_GEMINI_FLASH_MODEL } from '../config/models.js';
+import { logFlashFallback, FlashFallbackEvent } from '../telemetry/index.js';

 export async function handleFallback(
  config: Config,
@@ -18,7 +20,48 @@ export async function handleFallback(
    return handleQwenOAuthError(error);
  }

-  return null;
+  // Applicability Checks
+  if (authType !== AuthType.LOGIN_WITH_GOOGLE) return null;
+
+  const fallbackModel = DEFAULT_GEMINI_FLASH_MODEL;
+
+  if (failedModel === fallbackModel) return null;
+
+  // Consult UI Handler for Intent
+  const fallbackModelHandler = config.fallbackModelHandler;
+  if (typeof fallbackModelHandler !== 'function') return null;
+
+  try {
+    // Pass the specific failed model to the UI handler.
+    const intent = await fallbackModelHandler(
+      failedModel,
+      fallbackModel,
+      error,
+    );
+
+    // Process Intent and Update State
+    switch (intent) {
+      case 'retry':
+        // Activate fallback mode. The NEXT retry attempt will pick this up.
+        activateFallbackMode(config, authType);
+        return true; // Signal retryWithBackoff to continue.
+
+      case 'stop':
+        activateFallbackMode(config, authType);
+        return false;
+
+      case 'auth':
+        return false;
+
+      default:
+        throw new Error(
+          `Unexpected fallback intent received from fallbackModelHandler: "${intent}"`,
+        );
+    }
+  } catch (handlerError) {
+    console.error('Fallback UI handler failed:', handlerError);
+    return null;
+  }
 }

 /**
@@ -75,3 +118,12 @@ async function handleQwenOAuthError(error?: unknown): Promise<string | null> {
  // For other errors, don't handle them specially
  return null;
 }
+
+function activateFallbackMode(config: Config, authType: string | undefined) {
+  if (!config.isInFallbackMode()) {
+    config.setFallbackMode(true);
+    if (authType) {
+      logFlashFallback(config, new FlashFallbackEvent(authType));
+    }
+  }
+}
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -12,6 +12,7 @@ export * from './output/json-formatter.js';
 // Export Core Logic
 export * from './core/client.js';
 export * from './core/contentGenerator.js';
+export * from './core/loggingContentGenerator.js';
 export * from './core/geminiChat.js';
 export * from './core/logger.js';
 export * from './core/prompts.js';
@@ -23,7 +24,11 @@ export * from './core/nonInteractiveToolExecutor.js';

 export * from './fallback/types.js';

+export * from './code_assist/codeAssist.js';
+export * from './code_assist/oauth2.js';
 export * from './qwen/qwenOAuth2.js';
+export * from './code_assist/server.js';
+export * from './code_assist/types.js';

 // Export utilities
 export * from './utils/paths.js';
@@ -80,6 +85,9 @@ export * from './tools/tool-registry.js';
 // Export subagents (Phase 1)
 export * from './subagents/index.js';

+// Export skills
+export * from './skills/index.js';
+
 // Export prompt logic
 export * from './prompts/mcp-prompts.js';

@@ -101,6 +109,7 @@ export * from './tools/mcp-client-manager.js';
 export * from './tools/mcp-tool.js';
 export * from './tools/sdk-control-client-transport.js';
 export * from './tools/task.js';
+export * from './tools/skill.js';
 export * from './tools/todoWrite.js';
 export * from './tools/exitPlanMode.js';

--- a/packages/core/src/qwen/qwenOAuth2.ts
+++ b/packages/core/src/qwen/qwenOAuth2.ts
@@ -907,5 +907,3 @@ export async function clearQwenCredentials(): Promise<void> {
 function getQwenCachedCredentialPath(): string {
  return path.join(os.homedir(), QWEN_DIR, QWEN_CREDENTIAL_FILENAME);
 }
-
-export const clearCachedCredentialFile = clearQwenCredentials;
--- a/packages/core/src/skills/index.ts
+++ b/packages/core/src/skills/index.ts
@@ -0,0 +1,31 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @fileoverview Skills feature implementation
+ *
+ * This module provides the foundation for the skills feature, which allows
+ * users to define reusable skill configurations that can be loaded by the
+ * model via a dedicated Skills tool.
+ *
+ * Skills are stored as directories in `.qwen/skills/` (project-level) or
+ * `~/.qwen/skills/` (user-level), with each directory containing a SKILL.md
+ * file with YAML frontmatter for metadata.
+ */
+
+// Core types and interfaces
+export type {
+  SkillConfig,
+  SkillLevel,
+  SkillValidationResult,
+  ListSkillsOptions,
+  SkillErrorCode,
+} from './types.js';
+
+export { SkillError } from './types.js';
+
+// Main management class
+export { SkillManager } from './skill-manager.js';
--- a/packages/core/src/skills/skill-manager.test.ts
+++ b/packages/core/src/skills/skill-manager.test.ts
@@ -0,0 +1,463 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, it, expect, beforeEach, afterEach } from 'vitest';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import * as os from 'os';
+import { SkillManager } from './skill-manager.js';
+import { type SkillConfig, SkillError } from './types.js';
+import type { Config } from '../config/config.js';
+import { makeFakeConfig } from '../test-utils/config.js';
+
+// Mock file system operations
+vi.mock('fs/promises');
+vi.mock('os');
+
+// Mock yaml parser - use vi.hoisted for proper hoisting
+const mockParseYaml = vi.hoisted(() => vi.fn());
+
+vi.mock('../utils/yaml-parser.js', () => ({
+  parse: mockParseYaml,
+  stringify: vi.fn(),
+}));
+
+describe('SkillManager', () => {
+  let manager: SkillManager;
+  let mockConfig: Config;
+
+  beforeEach(() => {
+    // Create mock Config object using test utility
+    mockConfig = makeFakeConfig({});
+
+    // Mock the project root method
+    vi.spyOn(mockConfig, 'getProjectRoot').mockReturnValue('/test/project');
+
+    // Mock os.homedir
+    vi.mocked(os.homedir).mockReturnValue('/home/user');
+
+    // Reset and setup mocks
+    vi.clearAllMocks();
+
+    // Setup yaml parser mocks with sophisticated behavior
+    mockParseYaml.mockImplementation((yamlString: string) => {
+      // Handle different test cases based on YAML content
+      if (yamlString.includes('allowedTools:')) {
+        return {
+          name: 'test-skill',
+          description: 'A test skill',
+          allowedTools: ['read_file', 'write_file'],
+        };
+      }
+      if (yamlString.includes('name: skill1')) {
+        return { name: 'skill1', description: 'First skill' };
+      }
+      if (yamlString.includes('name: skill2')) {
+        return { name: 'skill2', description: 'Second skill' };
+      }
+      if (yamlString.includes('name: skill3')) {
+        return { name: 'skill3', description: 'Third skill' };
+      }
+      if (!yamlString.includes('name:')) {
+        return { description: 'A test skill' }; // Missing name case
+      }
+      if (!yamlString.includes('description:')) {
+        return { name: 'test-skill' }; // Missing description case
+      }
+      // Default case
+      return {
+        name: 'test-skill',
+        description: 'A test skill',
+      };
+    });
+
+    manager = new SkillManager(mockConfig);
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  const validSkillConfig: SkillConfig = {
+    name: 'test-skill',
+    description: 'A test skill',
+    level: 'project',
+    filePath: '/test/project/.qwen/skills/test-skill/SKILL.md',
+    body: 'You are a helpful assistant with this skill.',
+  };
+
+  const validMarkdown = `---
+name: test-skill
+description: A test skill
+---
+
+You are a helpful assistant with this skill.
+`;
+
+  describe('parseSkillContent', () => {
+    it('should parse valid markdown content', () => {
+      const config = manager.parseSkillContent(
+        validMarkdown,
+        validSkillConfig.filePath,
+        'project',
+      );
+
+      expect(config.name).toBe('test-skill');
+      expect(config.description).toBe('A test skill');
+      expect(config.body).toBe('You are a helpful assistant with this skill.');
+      expect(config.level).toBe('project');
+      expect(config.filePath).toBe(validSkillConfig.filePath);
+    });
+
+    it('should parse content with allowedTools', () => {
+      const markdownWithTools = `---
+name: test-skill
+description: A test skill
+allowedTools:
+  - read_file
+  - write_file
+---
+
+You are a helpful assistant with this skill.
+`;
+
+      const config = manager.parseSkillContent(
+        markdownWithTools,
+        validSkillConfig.filePath,
+        'project',
+      );
+
+      expect(config.allowedTools).toEqual(['read_file', 'write_file']);
+    });
+
+    it('should determine level from file path', () => {
+      const projectPath = '/test/project/.qwen/skills/test-skill/SKILL.md';
+      const userPath = '/home/user/.qwen/skills/test-skill/SKILL.md';
+
+      const projectConfig = manager.parseSkillContent(
+        validMarkdown,
+        projectPath,
+        'project',
+      );
+      const userConfig = manager.parseSkillContent(
+        validMarkdown,
+        userPath,
+        'user',
+      );
+
+      expect(projectConfig.level).toBe('project');
+      expect(userConfig.level).toBe('user');
+    });
+
+    it('should throw error for invalid frontmatter format', () => {
+      const invalidMarkdown = `No frontmatter here
+Just content`;
+
+      expect(() =>
+        manager.parseSkillContent(
+          invalidMarkdown,
+          validSkillConfig.filePath,
+          'project',
+        ),
+      ).toThrow(SkillError);
+    });
+
+    it('should throw error for missing name', () => {
+      const markdownWithoutName = `---
+description: A test skill
+---
+
+You are a helpful assistant.
+`;
+
+      expect(() =>
+        manager.parseSkillContent(
+          markdownWithoutName,
+          validSkillConfig.filePath,
+          'project',
+        ),
+      ).toThrow(SkillError);
+    });
+
+    it('should throw error for missing description', () => {
+      const markdownWithoutDescription = `---
+name: test-skill
+---
+
+You are a helpful assistant.
+`;
+
+      expect(() =>
+        manager.parseSkillContent(
+          markdownWithoutDescription,
+          validSkillConfig.filePath,
+          'project',
+        ),
+      ).toThrow(SkillError);
+    });
+  });
+
+  describe('validateConfig', () => {
+    it('should validate valid configuration', () => {
+      const result = manager.validateConfig(validSkillConfig);
+
+      expect(result.isValid).toBe(true);
+      expect(result.errors).toHaveLength(0);
+    });
+
+    it('should report error for missing name', () => {
+      const invalidConfig = { ...validSkillConfig, name: '' };
+      const result = manager.validateConfig(invalidConfig);
+
+      expect(result.isValid).toBe(false);
+      expect(result.errors).toContain('"name" cannot be empty');
+    });
+
+    it('should report error for missing description', () => {
+      const invalidConfig = { ...validSkillConfig, description: '' };
+      const result = manager.validateConfig(invalidConfig);
+
+      expect(result.isValid).toBe(false);
+      expect(result.errors).toContain('"description" cannot be empty');
+    });
+
+    it('should report error for invalid allowedTools type', () => {
+      const invalidConfig = {
+        ...validSkillConfig,
+        allowedTools: 'not-an-array' as unknown as string[],
+      };
+      const result = manager.validateConfig(invalidConfig);
+
+      expect(result.isValid).toBe(false);
+      expect(result.errors).toContain('"allowedTools" must be an array');
+    });
+
+    it('should warn for empty body', () => {
+      const configWithEmptyBody = { ...validSkillConfig, body: '' };
+      const result = manager.validateConfig(configWithEmptyBody);
+
+      expect(result.isValid).toBe(true); // Still valid
+      expect(result.warnings).toContain('Skill body is empty');
+    });
+  });
+
+  describe('loadSkill', () => {
+    it('should load skill from project level first', async () => {
+      vi.mocked(fs.readdir).mockResolvedValue([
+        { name: 'test-skill', isDirectory: () => true, isFile: () => false },
+      ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(validMarkdown);
+
+      const config = await manager.loadSkill('test-skill');
+
+      expect(config).toBeDefined();
+      expect(config!.name).toBe('test-skill');
+    });
+
+    it('should fall back to user level if project level fails', async () => {
+      vi.mocked(fs.readdir)
+        .mockRejectedValueOnce(new Error('Project dir not found')) // project level fails
+        .mockResolvedValueOnce([
+          { name: 'test-skill', isDirectory: () => true, isFile: () => false },
+        ] as unknown as Awaited<ReturnType<typeof fs.readdir>>); // user level succeeds
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(validMarkdown);
+
+      const config = await manager.loadSkill('test-skill');
+
+      expect(config).toBeDefined();
+      expect(config!.name).toBe('test-skill');
+    });
+
+    it('should return null if not found at either level', async () => {
+      vi.mocked(fs.readdir).mockRejectedValue(new Error('Directory not found'));
+
+      const config = await manager.loadSkill('nonexistent');
+
+      expect(config).toBeNull();
+    });
+  });
+
+  describe('loadSkillForRuntime', () => {
+    it('should load skill for runtime', async () => {
+      vi.mocked(fs.readdir).mockResolvedValueOnce([
+        { name: 'test-skill', isDirectory: () => true, isFile: () => false },
+      ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(validMarkdown); // SKILL.md
+
+      const config = await manager.loadSkillForRuntime('test-skill');
+
+      expect(config).toBeDefined();
+      expect(config!.name).toBe('test-skill');
+    });
+
+    it('should return null if skill not found', async () => {
+      vi.mocked(fs.readdir).mockRejectedValue(new Error('Directory not found'));
+
+      const config = await manager.loadSkillForRuntime('nonexistent');
+
+      expect(config).toBeNull();
+    });
+  });
+
+  describe('listSkills', () => {
+    beforeEach(() => {
+      // Mock directory listing for skills directories (with Dirent objects)
+      vi.mocked(fs.readdir)
+        .mockResolvedValueOnce([
+          { name: 'skill1', isDirectory: () => true, isFile: () => false },
+          { name: 'skill2', isDirectory: () => true, isFile: () => false },
+          {
+            name: 'not-a-dir.txt',
+            isDirectory: () => false,
+            isFile: () => true,
+          },
+        ] as unknown as Awaited<ReturnType<typeof fs.readdir>>)
+        .mockResolvedValueOnce([
+          { name: 'skill3', isDirectory: () => true, isFile: () => false },
+          { name: 'skill1', isDirectory: () => true, isFile: () => false },
+        ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+
+      // Mock file reading for valid skills
+      vi.mocked(fs.readFile).mockImplementation((filePath) => {
+        const pathStr = String(filePath);
+        if (pathStr.includes('skill1')) {
+          return Promise.resolve(`---
+name: skill1
+description: First skill
+---
+Skill 1 content`);
+        } else if (pathStr.includes('skill2')) {
+          return Promise.resolve(`---
+name: skill2
+description: Second skill
+---
+Skill 2 content`);
+        } else if (pathStr.includes('skill3')) {
+          return Promise.resolve(`---
+name: skill3
+description: Third skill
+---
+Skill 3 content`);
+        }
+        return Promise.reject(new Error('File not found'));
+      });
+    });
+
+    it('should list skills from both levels', async () => {
+      const skills = await manager.listSkills();
+
+      expect(skills).toHaveLength(3); // skill1 (project takes precedence), skill2, skill3
+      expect(skills.map((s) => s.name).sort()).toEqual([
+        'skill1',
+        'skill2',
+        'skill3',
+      ]);
+    });
+
+    it('should prioritize project level over user level', async () => {
+      const skills = await manager.listSkills();
+      const skill1 = skills.find((s) => s.name === 'skill1');
+
+      expect(skill1!.level).toBe('project');
+    });
+
+    it('should filter by level', async () => {
+      const projectSkills = await manager.listSkills({
+        level: 'project',
+      });
+
+      expect(projectSkills).toHaveLength(2); // skill1, skill2
+      expect(projectSkills.every((s) => s.level === 'project')).toBe(true);
+    });
+
+    it('should handle empty directories', async () => {
+      vi.mocked(fs.readdir).mockReset();
+      vi.mocked(fs.readdir).mockResolvedValue(
+        [] as unknown as Awaited<ReturnType<typeof fs.readdir>>,
+      );
+
+      const skills = await manager.listSkills({ force: true });
+
+      expect(skills).toHaveLength(0);
+    });
+
+    it('should handle directory read errors', async () => {
+      vi.mocked(fs.readdir).mockReset();
+      vi.mocked(fs.readdir).mockRejectedValue(new Error('Directory not found'));
+
+      const skills = await manager.listSkills({ force: true });
+
+      expect(skills).toHaveLength(0);
+    });
+  });
+
+  describe('getSkillsBaseDir', () => {
+    it('should return project-level base dir', () => {
+      const baseDir = manager.getSkillsBaseDir('project');
+
+      expect(baseDir).toBe(path.join('/test/project', '.qwen', 'skills'));
+    });
+
+    it('should return user-level base dir', () => {
+      const baseDir = manager.getSkillsBaseDir('user');
+
+      expect(baseDir).toBe(path.join('/home/user', '.qwen', 'skills'));
+    });
+  });
+
+  describe('change listeners', () => {
+    it('should notify listeners when cache is refreshed', async () => {
+      const listener = vi.fn();
+      manager.addChangeListener(listener);
+
+      vi.mocked(fs.readdir).mockResolvedValue(
+        [] as unknown as Awaited<ReturnType<typeof fs.readdir>>,
+      );
+
+      await manager.refreshCache();
+
+      expect(listener).toHaveBeenCalled();
+    });
+
+    it('should remove listener when cleanup function is called', async () => {
+      const listener = vi.fn();
+      const removeListener = manager.addChangeListener(listener);
+
+      removeListener();
+
+      vi.mocked(fs.readdir).mockResolvedValue(
+        [] as unknown as Awaited<ReturnType<typeof fs.readdir>>,
+      );
+
+      await manager.refreshCache();
+
+      expect(listener).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('parse errors', () => {
+    it('should track parse errors', async () => {
+      vi.mocked(fs.readdir).mockResolvedValue([
+        { name: 'bad-skill', isDirectory: () => true, isFile: () => false },
+      ] as unknown as Awaited<ReturnType<typeof fs.readdir>>);
+      vi.mocked(fs.access).mockResolvedValue(undefined);
+      vi.mocked(fs.readFile).mockResolvedValue(
+        'invalid content without frontmatter',
+      );
+
+      await manager.listSkills({ force: true });
+
+      const errors = manager.getParseErrors();
+      expect(errors.size).toBeGreaterThan(0);
+    });
+  });
+});
--- a/packages/core/src/skills/skill-manager.ts
+++ b/packages/core/src/skills/skill-manager.ts
@@ -0,0 +1,452 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import * as os from 'os';
+import { parse as parseYaml } from '../utils/yaml-parser.js';
+import type {
+  SkillConfig,
+  SkillLevel,
+  ListSkillsOptions,
+  SkillValidationResult,
+} from './types.js';
+import { SkillError, SkillErrorCode } from './types.js';
+import type { Config } from '../config/config.js';
+
+const QWEN_CONFIG_DIR = '.qwen';
+const SKILLS_CONFIG_DIR = 'skills';
+const SKILL_MANIFEST_FILE = 'SKILL.md';
+
+/**
+ * Manages skill configurations stored as directories containing SKILL.md files.
+ * Provides discovery, parsing, validation, and caching for skills.
+ */
+export class SkillManager {
+  private skillsCache: Map<SkillLevel, SkillConfig[]> | null = null;
+  private readonly changeListeners: Set<() => void> = new Set();
+  private parseErrors: Map<string, SkillError> = new Map();
+
+  constructor(private readonly config: Config) {}
+
+  /**
+   * Adds a listener that will be called when skills change.
+   * @returns A function to remove the listener.
+   */
+  addChangeListener(listener: () => void): () => void {
+    this.changeListeners.add(listener);
+    return () => {
+      this.changeListeners.delete(listener);
+    };
+  }
+
+  /**
+   * Notifies all registered change listeners.
+   */
+  private notifyChangeListeners(): void {
+    for (const listener of this.changeListeners) {
+      try {
+        listener();
+      } catch (error) {
+        console.warn('Skill change listener threw an error:', error);
+      }
+    }
+  }
+
+  /**
+   * Gets any parse errors that occurred during skill loading.
+   * @returns Map of skill paths to their parse errors.
+   */
+  getParseErrors(): Map<string, SkillError> {
+    return new Map(this.parseErrors);
+  }
+
+  /**
+   * Lists all available skills.
+   *
+   * @param options - Filtering options
+   * @returns Array of skill configurations
+   */
+  async listSkills(options: ListSkillsOptions = {}): Promise<SkillConfig[]> {
+    const skills: SkillConfig[] = [];
+    const seenNames = new Set<string>();
+
+    const levelsToCheck: SkillLevel[] = options.level
+      ? [options.level]
+      : ['project', 'user'];
+
+    // Check if we should use cache or force refresh
+    const shouldUseCache = !options.force && this.skillsCache !== null;
+
+    // Initialize cache if it doesn't exist or we're forcing a refresh
+    if (!shouldUseCache) {
+      await this.refreshCache();
+    }
+
+    // Collect skills from each level (project takes precedence over user)
+    for (const level of levelsToCheck) {
+      const levelSkills = this.skillsCache?.get(level) || [];
+
+      for (const skill of levelSkills) {
+        // Skip if we've already seen this name (precedence: project > user)
+        if (seenNames.has(skill.name)) {
+          continue;
+        }
+
+        skills.push(skill);
+        seenNames.add(skill.name);
+      }
+    }
+
+    // Sort by name for consistent ordering
+    skills.sort((a, b) => a.name.localeCompare(b.name));
+
+    return skills;
+  }
+
+  /**
+   * Loads a skill configuration by name.
+   * If level is specified, only searches that level.
+   * If level is omitted, searches project-level first, then user-level.
+   *
+   * @param name - Name of the skill to load
+   * @param level - Optional level to limit search to
+   * @returns SkillConfig or null if not found
+   */
+  async loadSkill(
+    name: string,
+    level?: SkillLevel,
+  ): Promise<SkillConfig | null> {
+    if (level) {
+      return this.findSkillByNameAtLevel(name, level);
+    }
+
+    // Try project level first
+    const projectSkill = await this.findSkillByNameAtLevel(name, 'project');
+    if (projectSkill) {
+      return projectSkill;
+    }
+
+    // Try user level
+    return this.findSkillByNameAtLevel(name, 'user');
+  }
+
+  /**
+   * Loads a skill with its full content, ready for runtime use.
+   * This includes loading additional files from the skill directory.
+   *
+   * @param name - Name of the skill to load
+   * @param level - Optional level to limit search to
+   * @returns SkillConfig or null if not found
+   */
+  async loadSkillForRuntime(
+    name: string,
+    level?: SkillLevel,
+  ): Promise<SkillConfig | null> {
+    const skill = await this.loadSkill(name, level);
+    if (!skill) {
+      return null;
+    }
+
+    return skill;
+  }
+
+  /**
+   * Validates a skill configuration.
+   *
+   * @param config - Configuration to validate
+   * @returns Validation result
+   */
+  validateConfig(config: Partial<SkillConfig>): SkillValidationResult {
+    const errors: string[] = [];
+    const warnings: string[] = [];
+
+    // Check required fields
+    if (typeof config.name !== 'string') {
+      errors.push('Missing or invalid "name" field');
+    } else if (config.name.trim() === '') {
+      errors.push('"name" cannot be empty');
+    }
+
+    if (typeof config.description !== 'string') {
+      errors.push('Missing or invalid "description" field');
+    } else if (config.description.trim() === '') {
+      errors.push('"description" cannot be empty');
+    }
+
+    // Validate allowedTools if present
+    if (config.allowedTools !== undefined) {
+      if (!Array.isArray(config.allowedTools)) {
+        errors.push('"allowedTools" must be an array');
+      } else {
+        for (const tool of config.allowedTools) {
+          if (typeof tool !== 'string') {
+            errors.push('"allowedTools" must contain only strings');
+            break;
+          }
+        }
+      }
+    }
+
+    // Warn if body is empty
+    if (!config.body || config.body.trim() === '') {
+      warnings.push('Skill body is empty');
+    }
+
+    return {
+      isValid: errors.length === 0,
+      errors,
+      warnings,
+    };
+  }
+
+  /**
+   * Refreshes the skills cache by loading all skills from disk.
+   */
+  async refreshCache(): Promise<void> {
+    const skillsCache = new Map<SkillLevel, SkillConfig[]>();
+    this.parseErrors.clear();
+
+    const levels: SkillLevel[] = ['project', 'user'];
+
+    for (const level of levels) {
+      const levelSkills = await this.listSkillsAtLevel(level);
+      skillsCache.set(level, levelSkills);
+    }
+
+    this.skillsCache = skillsCache;
+    this.notifyChangeListeners();
+  }
+
+  /**
+   * Parses a SKILL.md file and returns the configuration.
+   *
+   * @param filePath - Path to the SKILL.md file
+   * @param level - Storage level
+   * @returns SkillConfig
+   * @throws SkillError if parsing fails
+   */
+  parseSkillFile(filePath: string, level: SkillLevel): Promise<SkillConfig> {
+    return this.parseSkillFileInternal(filePath, level);
+  }
+
+  /**
+   * Internal implementation of skill file parsing.
+   */
+  private async parseSkillFileInternal(
+    filePath: string,
+    level: SkillLevel,
+  ): Promise<SkillConfig> {
+    let content: string;
+
+    try {
+      content = await fs.readFile(filePath, 'utf8');
+    } catch (error) {
+      const skillError = new SkillError(
+        `Failed to read skill file: ${error instanceof Error ? error.message : 'Unknown error'}`,
+        SkillErrorCode.FILE_ERROR,
+      );
+      this.parseErrors.set(filePath, skillError);
+      throw skillError;
+    }
+
+    return this.parseSkillContent(content, filePath, level);
+  }
+
+  /**
+   * Parses skill content from a string.
+   *
+   * @param content - File content
+   * @param filePath - File path for error reporting
+   * @param level - Storage level
+   * @returns SkillConfig
+   * @throws SkillError if parsing fails
+   */
+  parseSkillContent(
+    content: string,
+    filePath: string,
+    level: SkillLevel,
+  ): SkillConfig {
+    try {
+      // Split frontmatter and content
+      const frontmatterRegex = /^---\n([\s\S]*?)\n---\n([\s\S]*)$/;
+      const match = content.match(frontmatterRegex);
+
+      if (!match) {
+        throw new Error('Invalid format: missing YAML frontmatter');
+      }
+
+      const [, frontmatterYaml, body] = match;
+
+      // Parse YAML frontmatter
+      const frontmatter = parseYaml(frontmatterYaml) as Record<string, unknown>;
+
+      // Extract required fields
+      const nameRaw = frontmatter['name'];
+      const descriptionRaw = frontmatter['description'];
+
+      if (nameRaw == null || nameRaw === '') {
+        throw new Error('Missing "name" in frontmatter');
+      }
+
+      if (descriptionRaw == null || descriptionRaw === '') {
+        throw new Error('Missing "description" in frontmatter');
+      }
+
+      // Convert to strings
+      const name = String(nameRaw);
+      const description = String(descriptionRaw);
+
+      // Extract optional fields
+      const allowedToolsRaw = frontmatter['allowedTools'] as
+        | unknown[]
+        | undefined;
+      let allowedTools: string[] | undefined;
+
+      if (allowedToolsRaw !== undefined) {
+        if (Array.isArray(allowedToolsRaw)) {
+          allowedTools = allowedToolsRaw.map(String);
+        } else {
+          throw new Error('"allowedTools" must be an array');
+        }
+      }
+
+      const config: SkillConfig = {
+        name,
+        description,
+        allowedTools,
+        level,
+        filePath,
+        body: body.trim(),
+      };
+
+      // Validate the parsed configuration
+      const validation = this.validateConfig(config);
+      if (!validation.isValid) {
+        throw new Error(`Validation failed: ${validation.errors.join(', ')}`);
+      }
+
+      return config;
+    } catch (error) {
+      const skillError = new SkillError(
+        `Failed to parse skill file: ${error instanceof Error ? error.message : 'Unknown error'}`,
+        SkillErrorCode.PARSE_ERROR,
+      );
+      this.parseErrors.set(filePath, skillError);
+      throw skillError;
+    }
+  }
+
+  /**
+   * Gets the base directory for skills at a specific level.
+   *
+   * @param level - Storage level
+   * @returns Absolute directory path
+   */
+  getSkillsBaseDir(level: SkillLevel): string {
+    const baseDir =
+      level === 'project'
+        ? path.join(
+            this.config.getProjectRoot(),
+            QWEN_CONFIG_DIR,
+            SKILLS_CONFIG_DIR,
+          )
+        : path.join(os.homedir(), QWEN_CONFIG_DIR, SKILLS_CONFIG_DIR);
+
+    return baseDir;
+  }
+
+  /**
+   * Lists skills at a specific level.
+   *
+   * @param level - Storage level to scan
+   * @returns Array of skill configurations
+   */
+  private async listSkillsAtLevel(level: SkillLevel): Promise<SkillConfig[]> {
+    const projectRoot = this.config.getProjectRoot();
+    const homeDir = os.homedir();
+    const isHomeDirectory = path.resolve(projectRoot) === path.resolve(homeDir);
+
+    // If project level is requested but project root is same as home directory,
+    // return empty array to avoid conflicts between project and global skills
+    if (level === 'project' && isHomeDirectory) {
+      return [];
+    }
+
+    const baseDir = this.getSkillsBaseDir(level);
+
+    try {
+      const entries = await fs.readdir(baseDir, { withFileTypes: true });
+      const skills: SkillConfig[] = [];
+
+      for (const entry of entries) {
+        // Only process directories (each skill is a directory)
+        if (!entry.isDirectory()) continue;
+
+        const skillDir = path.join(baseDir, entry.name);
+        const skillManifest = path.join(skillDir, SKILL_MANIFEST_FILE);
+
+        try {
+          // Check if SKILL.md exists
+          await fs.access(skillManifest);
+
+          const config = await this.parseSkillFileInternal(
+            skillManifest,
+            level,
+          );
+          skills.push(config);
+        } catch (error) {
+          // Skip directories without valid SKILL.md
+          if (error instanceof SkillError) {
+            // Parse error was already recorded
+            console.warn(
+              `Failed to parse skill at ${skillDir}: ${error.message}`,
+            );
+          }
+          continue;
+        }
+      }
+
+      return skills;
+    } catch (_error) {
+      // Directory doesn't exist or can't be read
+      return [];
+    }
+  }
+
+  /**
+   * Finds a skill by name at a specific level.
+   *
+   * @param name - Name of the skill to find
+   * @param level - Storage level to search
+   * @returns SkillConfig or null if not found
+   */
+  private async findSkillByNameAtLevel(
+    name: string,
+    level: SkillLevel,
+  ): Promise<SkillConfig | null> {
+    await this.ensureLevelCache(level);
+
+    const levelSkills = this.skillsCache?.get(level) || [];
+
+    // Find the skill with matching name
+    return levelSkills.find((skill) => skill.name === name) || null;
+  }
+
+  /**
+   * Ensures the cache is populated for a specific level without loading other levels.
+   */
+  private async ensureLevelCache(level: SkillLevel): Promise<void> {
+    if (!this.skillsCache) {
+      this.skillsCache = new Map<SkillLevel, SkillConfig[]>();
+    }
+
+    if (!this.skillsCache.has(level)) {
+      const levelSkills = await this.listSkillsAtLevel(level);
+      this.skillsCache.set(level, levelSkills);
+    }
+  }
+}
--- a/packages/core/src/skills/types.ts
+++ b/packages/core/src/skills/types.ts
@@ -0,0 +1,105 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Represents the storage level for a skill configuration.
+ * - 'project': Stored in `.qwen/skills/` within the project directory
+ * - 'user': Stored in `~/.qwen/skills/` in the user's home directory
+ */
+export type SkillLevel = 'project' | 'user';
+
+/**
+ * Core configuration for a skill as stored in SKILL.md files.
+ * Each skill directory contains a SKILL.md file with YAML frontmatter
+ * containing metadata, followed by markdown content describing the skill.
+ */
+export interface SkillConfig {
+  /** Unique name identifier for the skill */
+  name: string;
+
+  /** Human-readable description of what this skill provides */
+  description: string;
+
+  /**
+   * Optional list of tool names that this skill is allowed to use.
+   * For v1, this is informational only (no gating).
+   */
+  allowedTools?: string[];
+
+  /**
+   * Storage level - determines where the configuration file is stored
+   */
+  level: SkillLevel;
+
+  /**
+   * Absolute path to the skill directory containing SKILL.md
+   */
+  filePath: string;
+
+  /**
+   * The markdown body content from SKILL.md (after the frontmatter)
+   */
+  body: string;
+}
+
+/**
+ * Runtime configuration for a skill when it's being actively used.
+ * Extends SkillConfig with additional runtime-specific fields.
+ */
+export type SkillRuntimeConfig = SkillConfig;
+
+/**
+ * Result of a validation operation on a skill configuration.
+ */
+export interface SkillValidationResult {
+  /** Whether the configuration is valid */
+  isValid: boolean;
+
+  /** Array of error messages if validation failed */
+  errors: string[];
+
+  /** Array of warning messages (non-blocking issues) */
+  warnings: string[];
+}
+
+/**
+ * Options for listing skills.
+ */
+export interface ListSkillsOptions {
+  /** Filter by storage level */
+  level?: SkillLevel;
+
+  /** Force refresh from disk, bypassing cache. Defaults to false. */
+  force?: boolean;
+}
+
+/**
+ * Error thrown when a skill operation fails.
+ */
+export class SkillError extends Error {
+  constructor(
+    message: string,
+    readonly code: SkillErrorCode,
+    readonly skillName?: string,
+  ) {
+    super(message);
+    this.name = 'SkillError';
+  }
+}
+
+/**
+ * Error codes for skill operations.
+ */
+export const SkillErrorCode = {
+  NOT_FOUND: 'NOT_FOUND',
+  INVALID_CONFIG: 'INVALID_CONFIG',
+  INVALID_NAME: 'INVALID_NAME',
+  FILE_ERROR: 'FILE_ERROR',
+  PARSE_ERROR: 'PARSE_ERROR',
+} as const;
+
+export type SkillErrorCode =
+  (typeof SkillErrorCode)[keyof typeof SkillErrorCode];
--- a/packages/core/src/telemetry/clearcut-logger/clearcut-logger.test.ts
+++ b/packages/core/src/telemetry/clearcut-logger/clearcut-logger.test.ts
@@ -30,6 +30,7 @@ import {
  ToolCallEvent,
 } from '../types.js';
 import { GIT_COMMIT_INFO, CLI_VERSION } from '../../generated/git-commit.js';
+import { UserAccountManager } from '../../utils/userAccountManager.js';
 import { InstallationManager } from '../../utils/installationManager.js';
 import { safeJsonStringify } from '../../utils/safeJsonStringify.js';

@@ -89,8 +90,10 @@ expect.extend({
  },
 });

+vi.mock('../../utils/userAccountManager.js');
 vi.mock('../../utils/installationManager.js');

+const mockUserAccount = vi.mocked(UserAccountManager.prototype);
 const mockInstallMgr = vi.mocked(InstallationManager.prototype);

 // TODO(richieforeman): Consider moving this to test setup globally.
@@ -125,7 +128,11 @@ describe('ClearcutLogger', () => {
    vi.unstubAllEnvs();
  });

-  function setup({ config = {} as Partial<ConfigParameters> } = {}) {
+  function setup({
+    config = {} as Partial<ConfigParameters>,
+    lifetimeGoogleAccounts = 1,
+    cachedGoogleAccount = 'test@google.com',
+  } = {}) {
    server.resetHandlers(
      http.post(CLEARCUT_URL, () => HttpResponse.text(EXAMPLE_RESPONSE)),
    );
@@ -139,6 +146,10 @@ describe('ClearcutLogger', () => {
    });
    ClearcutLogger.clearInstance();

+    mockUserAccount.getCachedGoogleAccount.mockReturnValue(cachedGoogleAccount);
+    mockUserAccount.getLifetimeGoogleAccounts.mockReturnValue(
+      lifetimeGoogleAccounts,
+    );
    mockInstallMgr.getInstallationId = vi
      .fn()
      .mockReturnValue('test-installation-id');
@@ -184,6 +195,19 @@ describe('ClearcutLogger', () => {
  });

  describe('createLogEvent', () => {
+    it('logs the total number of google accounts', () => {
+      const { logger } = setup({
+        lifetimeGoogleAccounts: 9001,
+      });
+
+      const event = logger?.createLogEvent(EventNames.API_ERROR, []);
+
+      expect(event?.event_metadata[0]).toContainEqual({
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_GOOGLE_ACCOUNTS_COUNT,
+        value: '9001',
+      });
+    });
+
    it('logs the current surface from a github action', () => {
      const { logger } = setup({});

@@ -227,6 +251,7 @@ describe('ClearcutLogger', () => {
      // Define expected values
      const session_id = 'test-session-id';
      const auth_type = AuthType.USE_GEMINI;
+      const google_accounts = 123;
      const surface = 'ide-1234';
      const cli_version = CLI_VERSION;
      const git_commit_hash = GIT_COMMIT_INFO;
@@ -235,6 +260,7 @@ describe('ClearcutLogger', () => {

      // Setup logger with expected values
      const { logger, loggerConfig } = setup({
+        lifetimeGoogleAccounts: google_accounts,
        config: {},
      });
      vi.spyOn(loggerConfig, 'getContentGeneratorConfig').mockReturnValue({
@@ -257,6 +283,10 @@ describe('ClearcutLogger', () => {
            gemini_cli_key: EventMetadataKey.GEMINI_CLI_AUTH_TYPE,
            value: JSON.stringify(auth_type),
          },
+          {
+            gemini_cli_key: EventMetadataKey.GEMINI_CLI_GOOGLE_ACCOUNTS_COUNT,
+            value: `${google_accounts}`,
+          },
          {
            gemini_cli_key: EventMetadataKey.GEMINI_CLI_SURFACE,
            value: surface,
@@ -374,14 +404,10 @@ describe('ClearcutLogger', () => {
          vi.stubEnv(key, value);
        }
        const event = logger?.createLogEvent(EventNames.API_ERROR, []);
-        expect(event?.event_metadata[0]).toEqual(
-          expect.arrayContaining([
-            {
-              gemini_cli_key: EventMetadataKey.GEMINI_CLI_SURFACE,
-              value: expectedValue,
-            },
-          ]),
-        );
+        expect(event?.event_metadata[0][3]).toEqual({
+          gemini_cli_key: EventMetadataKey.GEMINI_CLI_SURFACE,
+          value: expectedValue,
+        });
      },
    );
  });
--- a/packages/core/src/telemetry/clearcut-logger/clearcut-logger.ts
+++ b/packages/core/src/telemetry/clearcut-logger/clearcut-logger.ts
@@ -34,6 +34,7 @@ import type {
 import { EventMetadataKey } from './event-metadata-key.js';
 import type { Config } from '../../config/config.js';
 import { InstallationManager } from '../../utils/installationManager.js';
+import { UserAccountManager } from '../../utils/userAccountManager.js';
 import { safeJsonStringify } from '../../utils/safeJsonStringify.js';
 import { FixedDeque } from 'mnemonist';
 import { GIT_COMMIT_INFO, CLI_VERSION } from '../../generated/git-commit.js';
@@ -156,6 +157,7 @@ export class ClearcutLogger {
  private sessionData: EventValue[] = [];
  private promptId: string = '';
  private readonly installationManager: InstallationManager;
+  private readonly userAccountManager: UserAccountManager;

  /**
   * Queue of pending events that need to be flushed to the server.  New events
@@ -184,6 +186,7 @@ export class ClearcutLogger {
    this.events = new FixedDeque<LogEventEntry[]>(Array, MAX_EVENTS);
    this.promptId = config?.getSessionId() ?? '';
    this.installationManager = new InstallationManager();
+    this.userAccountManager = new UserAccountManager();
  }

  static getInstance(config?: Config): ClearcutLogger | undefined {
@@ -230,11 +233,14 @@ export class ClearcutLogger {
  }

  createLogEvent(eventName: EventNames, data: EventValue[] = []): LogEvent {
+    const email = this.userAccountManager.getCachedGoogleAccount();
+
    if (eventName !== EventNames.START_SESSION) {
      data.push(...this.sessionData);
    }
+    const totalAccounts = this.userAccountManager.getLifetimeGoogleAccounts();

-    data = this.addDefaultFields(data);
+    data = this.addDefaultFields(data, totalAccounts);

    const logEvent: LogEvent = {
      console_type: 'GEMINI_CLI',
@@ -243,7 +249,12 @@ export class ClearcutLogger {
      event_metadata: [data],
    };

-    logEvent.client_install_id = this.installationManager.getInstallationId();
+    // Should log either email or install ID, not both. See go/cloudmill-1p-oss-instrumentation#define-sessionable-id
+    if (email) {
+      logEvent.client_email = email;
+    } else {
+      logEvent.client_install_id = this.installationManager.getInstallationId();
+    }

    return logEvent;
  }
@@ -1007,7 +1018,7 @@ export class ClearcutLogger {
   * Adds default fields to data, and returns a new data array.  This fields
   * should exist on all log events.
   */
-  addDefaultFields(data: EventValue[]): EventValue[] {
+  addDefaultFields(data: EventValue[], totalAccounts: number): EventValue[] {
    const surface = determineSurface();

    const defaultLogMetadata: EventValue[] = [
@@ -1021,6 +1032,10 @@ export class ClearcutLogger {
          this.config?.getContentGeneratorConfig()?.authType,
        ),
      },
+      {
+        gemini_cli_key: EventMetadataKey.GEMINI_CLI_GOOGLE_ACCOUNTS_COUNT,
+        value: `${totalAccounts}`,
+      },
      {
        gemini_cli_key: EventMetadataKey.GEMINI_CLI_SURFACE,
        value: surface,
--- a/packages/core/src/telemetry/constants.ts
+++ b/packages/core/src/telemetry/constants.ts
@@ -33,6 +33,7 @@ export const EVENT_MALFORMED_JSON_RESPONSE =
 export const EVENT_FILE_OPERATION = 'qwen-code.file_operation';
 export const EVENT_MODEL_SLASH_COMMAND = 'qwen-code.slash_command.model';
 export const EVENT_SUBAGENT_EXECUTION = 'qwen-code.subagent_execution';
+export const EVENT_SKILL_LAUNCH = 'qwen-code.skill_launch';
 export const EVENT_AUTH = 'qwen-code.auth';

 // Performance Events
--- a/packages/core/src/telemetry/index.ts
+++ b/packages/core/src/telemetry/index.ts
@@ -44,6 +44,7 @@ export {
  logRipgrepFallback,
  logNextSpeakerCheck,
  logAuth,
+  logSkillLaunch,
 } from './loggers.js';
 export type { SlashCommandEvent, ChatCompressionEvent } from './types.js';
 export {
@@ -63,6 +64,7 @@ export {
  RipgrepFallbackEvent,
  NextSpeakerCheckEvent,
  AuthEvent,
+  SkillLaunchEvent,
 } from './types.js';
 export { makeSlashCommandEvent, makeChatCompressionEvent } from './types.js';
 export type { TelemetryEvent } from './types.js';
--- a/packages/core/src/telemetry/loggers.test.ts
+++ b/packages/core/src/telemetry/loggers.test.ts
@@ -83,6 +83,7 @@ import type {
 } from '@google/genai';
 import { DiscoveredMCPTool } from '../tools/mcp-tool.js';
 import * as uiTelemetry from './uiTelemetry.js';
+import { UserAccountManager } from '../utils/userAccountManager.js';
 import { makeFakeConfig } from '../test-utils/config.js';

 describe('loggers', () => {
@@ -100,6 +101,10 @@ describe('loggers', () => {
    vi.spyOn(uiTelemetry.uiTelemetryService, 'addEvent').mockImplementation(
      mockUiEvent.addEvent,
    );
+    vi.spyOn(
+      UserAccountManager.prototype,
+      'getCachedGoogleAccount',
+    ).mockReturnValue('test-user@example.com');
    vi.useFakeTimers();
    vi.setSystemTime(new Date('2025-01-01T00:00:00.000Z'));
  });
@@ -183,6 +188,7 @@ describe('loggers', () => {
        body: 'CLI configuration loaded.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_CLI_CONFIG,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          model: 'test-model',
@@ -200,6 +206,8 @@ describe('loggers', () => {
          mcp_tools: undefined,
          mcp_tools_count: undefined,
          output_format: 'json',
+          skills: undefined,
+          subagents: undefined,
        },
      });
    });
@@ -227,6 +235,7 @@ describe('loggers', () => {
        body: 'User prompt. Length: 11.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_USER_PROMPT,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          prompt_length: 11,
@@ -248,7 +257,7 @@ describe('loggers', () => {
      const event = new UserPromptEvent(
        11,
        'prompt-id-9',
-        AuthType.USE_GEMINI,
+        AuthType.CLOUD_SHELL,
        'test-prompt',
      );

@@ -258,11 +267,12 @@ describe('loggers', () => {
        body: 'User prompt. Length: 11.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_USER_PROMPT,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          prompt_length: 11,
          prompt_id: 'prompt-id-9',
-          auth_type: 'gemini-api-key',
+          auth_type: 'cloud-shell',
        },
      });
    });
@@ -305,7 +315,7 @@ describe('loggers', () => {
        'test-model',
        100,
        'prompt-id-1',
-        AuthType.USE_GEMINI,
+        AuthType.LOGIN_WITH_GOOGLE,
        usageData,
        'test-response',
      );
@@ -316,6 +326,7 @@ describe('loggers', () => {
        body: 'API response from test-model. Status: 200. Duration: 100ms.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_API_RESPONSE,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          [SemanticAttributes.HTTP_STATUS_CODE]: 200,
@@ -331,7 +342,7 @@ describe('loggers', () => {
          total_token_count: 0,
          response_text: 'test-response',
          prompt_id: 'prompt-id-1',
-          auth_type: 'gemini-api-key',
+          auth_type: 'oauth-personal',
        },
      });

@@ -377,6 +388,7 @@ describe('loggers', () => {
        body: 'API request to test-model.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_API_REQUEST,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          model: 'test-model',
@@ -395,6 +407,7 @@ describe('loggers', () => {
        body: 'API request to test-model.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_API_REQUEST,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          model: 'test-model',
@@ -419,6 +432,7 @@ describe('loggers', () => {
        body: 'Switching to flash as Fallback.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_FLASH_FALLBACK,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          auth_type: 'vertex-ai',
@@ -453,6 +467,7 @@ describe('loggers', () => {
      expect(emittedEvent.attributes).toEqual(
        expect.objectContaining({
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_RIPGREP_FALLBACK,
          error: 'ripgrep is not available',
        }),
@@ -471,6 +486,7 @@ describe('loggers', () => {
      expect(emittedEvent.attributes).toEqual(
        expect.objectContaining({
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_RIPGREP_FALLBACK,
          error: 'rg not found',
        }),
@@ -584,6 +600,7 @@ describe('loggers', () => {
        body: 'Tool call: test-function. Decision: accept. Success: true. Duration: 100ms.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_TOOL_CALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          function_name: 'test-function',
@@ -667,6 +684,7 @@ describe('loggers', () => {
        body: 'Tool call: test-function. Decision: reject. Success: false. Duration: 100ms.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_TOOL_CALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          function_name: 'test-function',
@@ -743,6 +761,7 @@ describe('loggers', () => {
        body: 'Tool call: test-function. Decision: modify. Success: true. Duration: 100ms.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_TOOL_CALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          function_name: 'test-function',
@@ -818,6 +837,7 @@ describe('loggers', () => {
        body: 'Tool call: test-function. Success: true. Duration: 100ms.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_TOOL_CALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          function_name: 'test-function',
@@ -892,6 +912,7 @@ describe('loggers', () => {
        body: 'Tool call: test-function. Success: false. Duration: 100ms.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_TOOL_CALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          function_name: 'test-function',
@@ -980,6 +1001,7 @@ describe('loggers', () => {
        body: 'Tool call: mock_mcp_tool. Success: true. Duration: 100ms.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_TOOL_CALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          function_name: 'mock_mcp_tool',
@@ -1027,6 +1049,7 @@ describe('loggers', () => {
        body: 'Malformed JSON response from test-model.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_MALFORMED_JSON_RESPONSE,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          model: 'test-model',
@@ -1070,6 +1093,7 @@ describe('loggers', () => {
        body: 'File operation: read. Lines: 10.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_FILE_OPERATION,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          tool_name: 'test-tool',
@@ -1115,6 +1139,7 @@ describe('loggers', () => {
        body: 'Tool output truncated for test-tool.',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': 'tool_output_truncated',
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          eventName: 'tool_output_truncated',
@@ -1161,6 +1186,7 @@ describe('loggers', () => {
        body: 'Installed extension vscode',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_EXTENSION_INSTALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          extension_name: 'vscode',
@@ -1199,6 +1225,7 @@ describe('loggers', () => {
        body: 'Uninstalled extension vscode',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_EXTENSION_UNINSTALL,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          extension_name: 'vscode',
@@ -1235,6 +1262,7 @@ describe('loggers', () => {
        body: 'Enabled extension vscode',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_EXTENSION_ENABLE,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          extension_name: 'vscode',
@@ -1271,6 +1299,7 @@ describe('loggers', () => {
        body: 'Disabled extension vscode',
        attributes: {
          'session.id': 'test-session-id',
+          'user.email': 'test-user@example.com',
          'event.name': EVENT_EXTENSION_DISABLE,
          'event.timestamp': '2025-01-01T00:00:00.000Z',
          extension_name: 'vscode',
--- a/packages/core/src/telemetry/loggers.ts
+++ b/packages/core/src/telemetry/loggers.ts
@@ -9,6 +9,7 @@ import { logs } from '@opentelemetry/api-logs';
 import { SemanticAttributes } from '@opentelemetry/semantic-conventions';
 import type { Config } from '../config/config.js';
 import { safeJsonStringify } from '../utils/safeJsonStringify.js';
+import { UserAccountManager } from '../utils/userAccountManager.js';
 import {
  EVENT_API_ERROR,
  EVENT_API_CANCEL,
@@ -37,6 +38,7 @@ import {
  EVENT_MALFORMED_JSON_RESPONSE,
  EVENT_INVALID_CHUNK,
  EVENT_AUTH,
+  EVENT_SKILL_LAUNCH,
 } from './constants.js';
 import {
  recordApiErrorMetrics,
@@ -84,6 +86,7 @@ import type {
  MalformedJsonResponseEvent,
  InvalidChunkEvent,
  AuthEvent,
+  SkillLaunchEvent,
 } from './types.js';
 import type { UiEvent } from './uiTelemetry.js';
 import { uiTelemetryService } from './uiTelemetry.js';
@@ -92,8 +95,11 @@ const shouldLogUserPrompts = (config: Config): boolean =>
  config.getTelemetryLogPromptsEnabled();

 function getCommonAttributes(config: Config): LogAttributes {
+  const userAccountManager = new UserAccountManager();
+  const email = userAccountManager.getCachedGoogleAccount();
  return {
    'session.id': config.getSessionId(),
+    ...(email && { 'user.email': email }),
  };
 }

@@ -123,6 +129,8 @@ export function logStartSession(
    mcp_tools: event.mcp_tools,
    mcp_tools_count: event.mcp_tools_count,
    output_format: event.output_format,
+    skills: event.skills,
+    subagents: event.subagents,
  };

  const logger = logs.getLogger(SERVICE_NAME);
@@ -865,3 +873,21 @@ export function logAuth(config: Config, event: AuthEvent): void {
  };
  logger.emit(logRecord);
 }
+
+export function logSkillLaunch(config: Config, event: SkillLaunchEvent): void {
+  if (!isTelemetrySdkInitialized()) return;
+
+  const attributes: LogAttributes = {
+    ...getCommonAttributes(config),
+    ...event,
+    'event.name': EVENT_SKILL_LAUNCH,
+    'event.timestamp': new Date().toISOString(),
+  };
+
+  const logger = logs.getLogger(SERVICE_NAME);
+  const logRecord: LogRecord = {
+    body: `Skill launch: ${event.skill_name}. Success: ${event.success}.`,
+    attributes,
+  };
+  logger.emit(logRecord);
+}
--- a/packages/core/src/telemetry/qwen-logger/qwen-logger.ts
+++ b/packages/core/src/telemetry/qwen-logger/qwen-logger.ts
@@ -38,6 +38,7 @@ import type {
  ModelSlashCommandEvent,
  ExtensionDisableEvent,
  AuthEvent,
+  SkillLaunchEvent,
  RipgrepFallbackEvent,
  EndSessionEvent,
 } from '../types.js';
@@ -391,6 +392,8 @@ export class QwenLogger {
        telemetry_enabled: event.telemetry_enabled,
        telemetry_log_user_prompts_enabled:
          event.telemetry_log_user_prompts_enabled,
+        skills: event.skills,
+        subagents: event.subagents,
      },
    });

@@ -827,6 +830,18 @@ export class QwenLogger {
    this.flushIfNeeded();
  }

+  logSkillLaunchEvent(event: SkillLaunchEvent): void {
+    const rumEvent = this.createActionEvent('misc', 'skill_launch', {
+      properties: {
+        skill_name: event.skill_name,
+        success: event.success ? 1 : 0,
+      },
+    });
+
+    this.enqueueLogEvent(rumEvent);
+    this.flushIfNeeded();
+  }
+
  logChatCompressionEvent(event: ChatCompressionEvent): void {
    const rumEvent = this.createActionEvent('misc', 'chat_compression', {
      properties: {
--- a/packages/core/src/telemetry/types.ts
+++ b/packages/core/src/telemetry/types.ts
@@ -18,6 +18,9 @@ import {
 import type { FileOperation } from './metrics.js';
 export { ToolCallDecision };
 import type { OutputFormat } from '../output/types.js';
+import { ToolNames } from '../tools/tool-names.js';
+import type { SkillTool } from '../tools/skill.js';
+import type { TaskTool } from '../tools/task.js';

 export interface BaseTelemetryEvent {
  'event.name': string;
@@ -47,6 +50,8 @@ export class StartSessionEvent implements BaseTelemetryEvent {
  mcp_tools_count?: number;
  mcp_tools?: string;
  output_format: OutputFormat;
+  skills?: string;
+  subagents?: string;

  constructor(config: Config) {
    const generatorConfig = config.getContentGeneratorConfig();
@@ -79,6 +84,7 @@ export class StartSessionEvent implements BaseTelemetryEvent {
      config.getFileFilteringRespectGitIgnore();
    this.mcp_servers_count = mcpServers ? Object.keys(mcpServers).length : 0;
    this.output_format = config.getOutputFormat();
+
    if (toolRegistry) {
      const mcpTools = toolRegistry
        .getAllTools()
@@ -87,6 +93,22 @@ export class StartSessionEvent implements BaseTelemetryEvent {
      this.mcp_tools = mcpTools
        .map((tool) => (tool as DiscoveredMCPTool).name)
        .join(',');
+
+      const skillTool = toolRegistry.getTool(ToolNames.SKILL) as
+        | SkillTool
+        | undefined;
+      const skillNames = skillTool?.getAvailableSkillNames?.();
+      if (skillNames && skillNames.length > 0) {
+        this.skills = skillNames.join(',');
+      }
+
+      const taskTool = toolRegistry.getTool(ToolNames.TASK) as
+        | TaskTool
+        | undefined;
+      const subagentNames = taskTool?.getAvailableSubagentNames?.();
+      if (subagentNames && subagentNames.length > 0) {
+        this.subagents = subagentNames.join(',');
+      }
    }
  }
 }
@@ -721,6 +743,20 @@ export class AuthEvent implements BaseTelemetryEvent {
  }
 }

+export class SkillLaunchEvent implements BaseTelemetryEvent {
+  'event.name': 'skill_launch';
+  'event.timestamp': string;
+  skill_name: string;
+  success: boolean;
+
+  constructor(skill_name: string, success: boolean) {
+    this['event.name'] = 'skill_launch';
+    this['event.timestamp'] = new Date().toISOString();
+    this.skill_name = skill_name;
+    this.success = success;
+  }
+}
+
 export type TelemetryEvent =
  | StartSessionEvent
  | EndSessionEvent
@@ -749,7 +785,8 @@ export type TelemetryEvent =
  | ExtensionUninstallEvent
  | ToolOutputTruncatedEvent
  | ModelSlashCommandEvent
-  | AuthEvent;
+  | AuthEvent
+  | SkillLaunchEvent;

 export class ExtensionDisableEvent implements BaseTelemetryEvent {
  'event.name': 'extension_disable';
--- a/packages/core/src/tools/ls.test.ts
+++ b/packages/core/src/tools/ls.test.ts
@@ -31,6 +31,8 @@ describe('LSTool', () => {
      tempSecondaryDir,
    ]);

+    const userSkillsBase = path.join(os.homedir(), '.qwen', 'skills');
+
    mockConfig = {
      getTargetDir: () => tempRootDir,
      getWorkspaceContext: () => mockWorkspaceContext,
@@ -39,6 +41,9 @@ describe('LSTool', () => {
        respectGitIgnore: true,
        respectQwenIgnore: true,
      }),
+      storage: {
+        getUserSkillsDir: () => userSkillsBase,
+      },
    } as unknown as Config;

    lsTool = new LSTool(mockConfig);
@@ -288,7 +293,7 @@ describe('LSTool', () => {
      };
      const invocation = lsTool.build(params);
      const description = invocation.getDescription();
-      const expected = path.relative(tempRootDir, params.path);
+      const expected = path.resolve(params.path);
      expect(description).toBe(expected);
    });
  });
--- a/packages/core/src/tools/ls.ts
+++ b/packages/core/src/tools/ls.ts
@@ -9,6 +9,7 @@ import path from 'node:path';
 import type { ToolInvocation, ToolResult } from './tools.js';
 import { BaseDeclarativeTool, BaseToolInvocation, Kind } from './tools.js';
 import { makeRelative, shortenPath } from '../utils/paths.js';
+import { isSubpath } from '../utils/paths.js';
 import type { Config } from '../config/config.js';
 import { DEFAULT_FILE_FILTERING_OPTIONS } from '../config/constants.js';
 import { ToolErrorType } from './tool-error.js';
@@ -311,8 +312,14 @@ export class LSTool extends BaseDeclarativeTool<LSToolParams, ToolResult> {
      return `Path must be absolute: ${params.path}`;
    }

+    const userSkillsBase = this.config.storage.getUserSkillsDir();
+    const isUnderUserSkills = isSubpath(userSkillsBase, params.path);
+
    const workspaceContext = this.config.getWorkspaceContext();
-    if (!workspaceContext.isPathWithinWorkspace(params.path)) {
+    if (
+      !workspaceContext.isPathWithinWorkspace(params.path) &&
+      !isUnderUserSkills
+    ) {
      const directories = workspaceContext.getDirectories();
      return `Path must be within one of the workspace directories: ${directories.join(
        ', ',
--- a/packages/core/src/tools/mcp-client.test.ts
+++ b/packages/core/src/tools/mcp-client.test.ts
@@ -217,9 +217,9 @@ describe('mcp-client', () => {
          false,
        );

-        expect(transport).toBeInstanceOf(StreamableHTTPClientTransport);
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        expect((transport as any)._url).toEqual(new URL('http://test-server'));
+        expect(transport).toEqual(
+          new StreamableHTTPClientTransport(new URL('http://test-server'), {}),
+        );
      });

      it('with headers', async () => {
@@ -232,13 +232,13 @@ describe('mcp-client', () => {
          false,
        );

-        expect(transport).toBeInstanceOf(StreamableHTTPClientTransport);
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        expect((transport as any)._url).toEqual(new URL('http://test-server'));
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        expect((transport as any)._requestInit?.headers).toEqual({
-          Authorization: 'derp',
-        });
+        expect(transport).toEqual(
+          new StreamableHTTPClientTransport(new URL('http://test-server'), {
+            requestInit: {
+              headers: { Authorization: 'derp' },
+            },
+          }),
+        );
      });
    });

@@ -251,9 +251,9 @@ describe('mcp-client', () => {
          },
          false,
        );
-        expect(transport).toBeInstanceOf(SSEClientTransport);
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        expect((transport as any)._url).toEqual(new URL('http://test-server'));
+        expect(transport).toEqual(
+          new SSEClientTransport(new URL('http://test-server'), {}),
+        );
      });

      it('with headers', async () => {
@@ -266,13 +266,13 @@ describe('mcp-client', () => {
          false,
        );

-        expect(transport).toBeInstanceOf(SSEClientTransport);
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        expect((transport as any)._url).toEqual(new URL('http://test-server'));
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        expect((transport as any)._requestInit?.headers).toEqual({
-          Authorization: 'derp',
-        });
+        expect(transport).toEqual(
+          new SSEClientTransport(new URL('http://test-server'), {
+            requestInit: {
+              headers: { Authorization: 'derp' },
+            },
+          }),
+        );
      });
    });

--- a/packages/core/src/tools/read-file.test.ts
+++ b/packages/core/src/tools/read-file.test.ts
@@ -40,6 +40,7 @@ describe('ReadFileTool', () => {
      getWorkspaceContext: () => createMockWorkspaceContext(tempRootDir),
      storage: {
        getProjectTempDir: () => path.join(tempRootDir, '.temp'),
+        getUserSkillsDir: () => path.join(os.homedir(), '.qwen', 'skills'),
      },
      getTruncateToolOutputThreshold: () => 2500,
      getTruncateToolOutputLines: () => 500,
--- a/packages/core/src/tools/read-file.ts
+++ b/packages/core/src/tools/read-file.ts
@@ -20,6 +20,7 @@ import { FileOperation } from '../telemetry/metrics.js';
 import { getProgrammingLanguage } from '../telemetry/telemetry-utils.js';
 import { logFileOperation } from '../telemetry/loggers.js';
 import { FileOperationEvent } from '../telemetry/types.js';
+import { isSubpath } from '../utils/paths.js';

 /**
 * Parameters for the ReadFile tool
@@ -183,15 +184,20 @@ export class ReadFileTool extends BaseDeclarativeTool<

    const workspaceContext = this.config.getWorkspaceContext();
    const projectTempDir = this.config.storage.getProjectTempDir();
+    const userSkillsDir = this.config.storage.getUserSkillsDir();
    const resolvedFilePath = path.resolve(filePath);
-    const resolvedProjectTempDir = path.resolve(projectTempDir);
-    const isWithinTempDir =
-      resolvedFilePath.startsWith(resolvedProjectTempDir + path.sep) ||
-      resolvedFilePath === resolvedProjectTempDir;
+    const isWithinTempDir = isSubpath(projectTempDir, resolvedFilePath);
+    const isWithinUserSkills = isSubpath(userSkillsDir, resolvedFilePath);

-    if (!workspaceContext.isPathWithinWorkspace(filePath) && !isWithinTempDir) {
+    if (
+      !workspaceContext.isPathWithinWorkspace(filePath) &&
+      !isWithinTempDir &&
+      !isWithinUserSkills
+    ) {
      const directories = workspaceContext.getDirectories();
-      return `File path must be within one of the workspace directories: ${directories.join(', ')} or within the project temp directory: ${projectTempDir}`;
+      return `File path must be within one of the workspace directories: ${directories.join(
+        ', ',
+      )} or within the project temp directory: ${projectTempDir}`;
    }
    if (params.offset !== undefined && params.offset < 0) {
      return 'Offset must be a non-negative number';
--- a/packages/core/src/tools/skill.test.ts
+++ b/packages/core/src/tools/skill.test.ts
@@ -0,0 +1,442 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+import { SkillTool, type SkillParams } from './skill.js';
+import type { PartListUnion } from '@google/genai';
+import type { ToolResultDisplay } from './tools.js';
+import type { Config } from '../config/config.js';
+import { SkillManager } from '../skills/skill-manager.js';
+import type { SkillConfig } from '../skills/types.js';
+import { partToString } from '../utils/partUtils.js';
+
+// Type for accessing protected methods in tests
+type SkillToolWithProtectedMethods = SkillTool & {
+  createInvocation: (params: SkillParams) => {
+    execute: (
+      signal?: AbortSignal,
+      updateOutput?: (output: ToolResultDisplay) => void,
+    ) => Promise<{
+      llmContent: PartListUnion;
+      returnDisplay: ToolResultDisplay;
+    }>;
+    getDescription: () => string;
+    shouldConfirmExecute: () => Promise<boolean>;
+  };
+};
+
+// Mock dependencies
+vi.mock('../skills/skill-manager.js');
+vi.mock('../telemetry/index.js', () => ({
+  logSkillLaunch: vi.fn(),
+  SkillLaunchEvent: class {
+    constructor(
+      public skill_name: string,
+      public success: boolean,
+    ) {}
+  },
+}));
+
+const MockedSkillManager = vi.mocked(SkillManager);
+
+describe('SkillTool', () => {
+  let config: Config;
+  let skillTool: SkillTool;
+  let mockSkillManager: SkillManager;
+  let changeListeners: Array<() => void>;
+
+  const mockSkills: SkillConfig[] = [
+    {
+      name: 'code-review',
+      description: 'Specialized skill for reviewing code quality',
+      level: 'project',
+      filePath: '/project/.qwen/skills/code-review/SKILL.md',
+      body: 'Review code for quality and best practices.',
+    },
+    {
+      name: 'testing',
+      description: 'Skill for writing and running tests',
+      level: 'user',
+      filePath: '/home/user/.qwen/skills/testing/SKILL.md',
+      body: 'Help write comprehensive tests.',
+      allowedTools: ['read_file', 'write_file', 'shell'],
+    },
+  ];
+
+  beforeEach(async () => {
+    // Setup fake timers
+    vi.useFakeTimers();
+
+    // Create mock config
+    config = {
+      getProjectRoot: vi.fn().mockReturnValue('/test/project'),
+      getSessionId: vi.fn().mockReturnValue('test-session-id'),
+      getSkillManager: vi.fn(),
+      getGeminiClient: vi.fn().mockReturnValue(undefined),
+    } as unknown as Config;
+
+    changeListeners = [];
+
+    // Setup SkillManager mock
+    mockSkillManager = {
+      listSkills: vi.fn().mockResolvedValue(mockSkills),
+      loadSkill: vi.fn(),
+      loadSkillForRuntime: vi.fn(),
+      addChangeListener: vi.fn((listener: () => void) => {
+        changeListeners.push(listener);
+        return () => {
+          const index = changeListeners.indexOf(listener);
+          if (index >= 0) {
+            changeListeners.splice(index, 1);
+          }
+        };
+      }),
+      getParseErrors: vi.fn().mockReturnValue(new Map()),
+    } as unknown as SkillManager;
+
+    MockedSkillManager.mockImplementation(() => mockSkillManager);
+
+    // Make config return the mock SkillManager
+    vi.mocked(config.getSkillManager).mockReturnValue(mockSkillManager);
+
+    // Create SkillTool instance
+    skillTool = new SkillTool(config);
+
+    // Allow async initialization to complete
+    await vi.runAllTimersAsync();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+    vi.clearAllMocks();
+  });
+
+  describe('initialization', () => {
+    it('should initialize with correct name and properties', () => {
+      expect(skillTool.name).toBe('skill');
+      expect(skillTool.displayName).toBe('Skill');
+      expect(skillTool.kind).toBe('read');
+    });
+
+    it('should load available skills during initialization', () => {
+      expect(mockSkillManager.listSkills).toHaveBeenCalled();
+    });
+
+    it('should subscribe to skill manager changes', () => {
+      expect(mockSkillManager.addChangeListener).toHaveBeenCalledTimes(1);
+    });
+
+    it('should update description with available skills', () => {
+      expect(skillTool.description).toContain('code-review');
+      expect(skillTool.description).toContain(
+        'Specialized skill for reviewing code quality',
+      );
+      expect(skillTool.description).toContain('testing');
+      expect(skillTool.description).toContain(
+        'Skill for writing and running tests',
+      );
+    });
+
+    it('should handle empty skills list gracefully', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue([]);
+
+      const emptySkillTool = new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      expect(emptySkillTool.description).toContain(
+        'No skills are currently configured',
+      );
+    });
+
+    it('should handle skill loading errors gracefully', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockRejectedValue(
+        new Error('Loading failed'),
+      );
+
+      const consoleSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+
+      new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      expect(consoleSpy).toHaveBeenCalledWith(
+        'Failed to load skills for Skills tool:',
+        expect.any(Error),
+      );
+      consoleSpy.mockRestore();
+    });
+  });
+
+  describe('schema generation', () => {
+    it('should expose static schema without dynamic enums', () => {
+      const schema = skillTool.schema;
+      const properties = schema.parametersJsonSchema as {
+        properties: {
+          skill: {
+            type: string;
+            description: string;
+            enum?: string[];
+          };
+        };
+      };
+      expect(properties.properties.skill.type).toBe('string');
+      expect(properties.properties.skill.description).toBe(
+        'The skill name (no arguments). E.g., "pdf" or "xlsx"',
+      );
+      expect(properties.properties.skill.enum).toBeUndefined();
+    });
+
+    it('should keep schema static even when no skills available', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue([]);
+
+      const emptySkillTool = new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      const schema = emptySkillTool.schema;
+      const properties = schema.parametersJsonSchema as {
+        properties: {
+          skill: {
+            type: string;
+            description: string;
+            enum?: string[];
+          };
+        };
+      };
+      expect(properties.properties.skill.type).toBe('string');
+      expect(properties.properties.skill.description).toBe(
+        'The skill name (no arguments). E.g., "pdf" or "xlsx"',
+      );
+      expect(properties.properties.skill.enum).toBeUndefined();
+    });
+  });
+
+  describe('validateToolParams', () => {
+    it('should validate valid parameters', () => {
+      const result = skillTool.validateToolParams({ skill: 'code-review' });
+      expect(result).toBeNull();
+    });
+
+    it('should reject empty skill', () => {
+      const result = skillTool.validateToolParams({ skill: '' });
+      expect(result).toBe('Parameter "skill" must be a non-empty string.');
+    });
+
+    it('should reject non-existent skill', () => {
+      const result = skillTool.validateToolParams({
+        skill: 'non-existent',
+      });
+      expect(result).toBe(
+        'Skill "non-existent" not found. Available skills: code-review, testing',
+      );
+    });
+
+    it('should show appropriate message when no skills available', async () => {
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue([]);
+
+      const emptySkillTool = new SkillTool(config);
+      await vi.runAllTimersAsync();
+
+      const result = emptySkillTool.validateToolParams({
+        skill: 'non-existent',
+      });
+      expect(result).toBe(
+        'Skill "non-existent" not found. No skills are currently available.',
+      );
+    });
+  });
+
+  describe('refreshSkills', () => {
+    it('should refresh when change listener fires', async () => {
+      const newSkills: SkillConfig[] = [
+        {
+          name: 'new-skill',
+          description: 'A brand new skill',
+          level: 'project',
+          filePath: '/project/.qwen/skills/new-skill/SKILL.md',
+          body: 'New skill content.',
+        },
+      ];
+
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValueOnce(newSkills);
+
+      const listener = changeListeners[0];
+      expect(listener).toBeDefined();
+
+      listener?.();
+      await vi.runAllTimersAsync();
+
+      expect(skillTool.description).toContain('new-skill');
+      expect(skillTool.description).toContain('A brand new skill');
+    });
+
+    it('should refresh available skills and update description', async () => {
+      const newSkills: SkillConfig[] = [
+        {
+          name: 'test-skill',
+          description: 'A test skill',
+          level: 'project',
+          filePath: '/project/.qwen/skills/test-skill/SKILL.md',
+          body: 'Test content.',
+        },
+      ];
+
+      vi.mocked(mockSkillManager.listSkills).mockResolvedValue(newSkills);
+
+      await skillTool.refreshSkills();
+
+      expect(skillTool.description).toContain('test-skill');
+      expect(skillTool.description).toContain('A test skill');
+    });
+  });
+
+  describe('SkillToolInvocation', () => {
+    const mockRuntimeConfig: SkillConfig = {
+      ...mockSkills[0],
+    };
+
+    beforeEach(() => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(
+        mockRuntimeConfig,
+      );
+    });
+
+    it('should execute skill load successfully', async () => {
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      expect(mockSkillManager.loadSkillForRuntime).toHaveBeenCalledWith(
+        'code-review',
+      );
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain(
+        'Base directory for this skill: /project/.qwen/skills/code-review',
+      );
+      expect(llmText.trim()).toContain(
+        'Review code for quality and best practices.',
+      );
+
+      expect(result.returnDisplay).toBe('Launching skill: code-review');
+    });
+
+    it('should include allowedTools in result when present', async () => {
+      const skillWithTools: SkillConfig = {
+        ...mockSkills[1],
+      };
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(
+        skillWithTools,
+      );
+
+      const params: SkillParams = {
+        skill: 'testing',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain('testing');
+      // Base description is omitted from llmContent; ensure body is present.
+      expect(llmText).toContain('Help write comprehensive tests.');
+
+      expect(result.returnDisplay).toBe('Launching skill: testing');
+    });
+
+    it('should handle skill not found error', async () => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(null);
+
+      const params: SkillParams = {
+        skill: 'non-existent',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain('Skill "non-existent" not found');
+    });
+
+    it('should handle execution errors gracefully', async () => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockRejectedValue(
+        new Error('Loading failed'),
+      );
+
+      const consoleSpy = vi
+        .spyOn(console, 'error')
+        .mockImplementation(() => {});
+
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).toContain('Failed to load skill');
+      expect(llmText).toContain('Loading failed');
+
+      consoleSpy.mockRestore();
+    });
+
+    it('should not require confirmation', async () => {
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const shouldConfirm = await invocation.shouldConfirmExecute();
+
+      expect(shouldConfirm).toBe(false);
+    });
+
+    it('should provide correct description', () => {
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const description = invocation.getDescription();
+
+      expect(description).toBe('Launching skill: "code-review"');
+    });
+
+    it('should handle skill without additional files', async () => {
+      vi.mocked(mockSkillManager.loadSkillForRuntime).mockResolvedValue(
+        mockSkills[0],
+      );
+
+      const params: SkillParams = {
+        skill: 'code-review',
+      };
+
+      const invocation = (
+        skillTool as SkillToolWithProtectedMethods
+      ).createInvocation(params);
+      const result = await invocation.execute();
+
+      const llmText = partToString(result.llmContent);
+      expect(llmText).not.toContain('## Additional Files');
+
+      expect(result.returnDisplay).toBe('Launching skill: code-review');
+    });
+  });
+});
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
tanzhenxin	251031cfc5	fix a link in skills.md	2025-12-23 15:09:23 +08:00
tanzhenxin	77c257d9d0	fix flaky tests	2025-12-23 14:50:47 +08:00
tanzhenxin	4311af96eb	add docs	2025-12-23 10:53:09 +08:00
tanzhenxin	b49c11e9a2	add experimental-skills flag to enable skills feature	2025-12-23 10:24:57 +08:00
tanzhenxin	9cdd85c62a	Merge branch 'main' into feat/skills	2025-12-22 16:00:57 +08:00
tanzhenxin	177fc42f04	Merge branch 'main' into feat/skills	2025-12-15 14:25:56 +08:00
tanzhenxin	2560c2d1a2	Merge branch 'main' into feat/skills	2025-12-11 14:50:07 +08:00
tanzhenxin	bd6e16d41b	draft version of skill tool feature	2025-12-10 17:18:44 +08:00