feat: subagent runtime & CLI display - wip

packages/core/src/subagents/subagent-events.ts

@@ -0,0 +1,89 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { EventEmitter } from 'events';
+
+export type SubAgentEvent =
+  | 'start'
+  | 'round_start'
+  | 'round_end'
+  | 'model_text'
+  | 'tool_call'
+  | 'tool_result'
+  | 'finish'
+  | 'error';
+
+export interface SubAgentModelTextEvent {
+  subagentId: string;
+  round: number;
+  text: string;
+  timestamp: number;
+}
+
+export interface SubAgentStartEvent {
+  subagentId: string;
+  name: string;
+  model?: string;
+  tools: string[];
+  timestamp: number;
+}
+
+export interface SubAgentRoundEvent {
+  subagentId: string;
+  round: number;
+  promptId: string;
+  timestamp: number;
+}
+
+export interface SubAgentToolCallEvent {
+  subagentId: string;
+  round: number;
+  callId: string;
+  name: string;
+  args: Record<string, unknown>;
+  timestamp: number;
+}
+
+export interface SubAgentToolResultEvent {
+  subagentId: string;
+  round: number;
+  callId: string;
+  name: string;
+  success: boolean;
+  error?: string;
+  durationMs?: number;
+  timestamp: number;
+}
+
+export interface SubAgentFinishEvent {
+  subagentId: string;
+  terminate_reason: string;
+  timestamp: number;
+  rounds?: number;
+  totalDurationMs?: number;
+  totalToolCalls?: number;
+  successfulToolCalls?: number;
+  failedToolCalls?: number;
+  inputTokens?: number;
+  outputTokens?: number;
+  totalTokens?: number;
+}
+
+export class SubAgentEventEmitter {
+  private ee = new EventEmitter();
+
+  on(event: SubAgentEvent, listener: (...args: unknown[]) => void) {
+    this.ee.on(event, listener);
+  }
+
+  off(event: SubAgentEvent, listener: (...args: unknown[]) => void) {
+    this.ee.off(event, listener);
+  }
+
+  emit(event: SubAgentEvent, payload: unknown) {
+    this.ee.emit(event, payload);
+  }
+}