From 472df045d366217e23d7cf6eddd0b4690930f353 Mon Sep 17 00:00:00 2001
From: Fan <koala99.zf@gmail.com>
Date: Tue, 26 Aug 2025 17:01:09 +0800
Subject: [PATCH] Fix parallel tool use (#400)

---
 .../core/src/core/openaiContentGenerator.ts   | 34 +++++++++++++++++--
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/packages/core/src/core/openaiContentGenerator.ts b/packages/core/src/core/openaiContentGenerator.ts
index 8f05f2e0..be681b0a 100644
--- a/packages/core/src/core/openaiContentGenerator.ts
+++ b/packages/core/src/core/openaiContentGenerator.ts
@@ -1351,7 +1351,9 @@ export class OpenAIContentGenerator implements ContentGenerator {
 
       // Handle text content
       if (choice.delta?.content) {
-        parts.push({ text: choice.delta.content });
+        if (typeof choice.delta.content === 'string') {
+          parts.push({ text: choice.delta.content });
+        }
       }
 
       // Handle tool calls - only accumulate during streaming, emit when complete
@@ -1371,10 +1373,36 @@ export class OpenAIContentGenerator implements ContentGenerator {
             accumulatedCall.id = toolCall.id;
           }
           if (toolCall.function?.name) {
+            // If this is a new function name, reset the arguments
+            if (accumulatedCall.name !== toolCall.function.name) {
+              accumulatedCall.arguments = '';
+            }
             accumulatedCall.name = toolCall.function.name;
           }
           if (toolCall.function?.arguments) {
-            accumulatedCall.arguments += toolCall.function.arguments;
+            // Check if we already have a complete JSON object
+            const currentArgs = accumulatedCall.arguments;
+            const newArgs = toolCall.function.arguments;
+
+            // If current arguments already form a complete JSON and new arguments start a new object,
+            // this indicates a new tool call with the same name
+            let shouldReset = false;
+            if (currentArgs && newArgs.trim().startsWith('{')) {
+              try {
+                JSON.parse(currentArgs);
+                // If we can parse current arguments as complete JSON and new args start with {,
+                // this is likely a new tool call
+                shouldReset = true;
+              } catch {
+                // Current arguments are not complete JSON, continue accumulating
+              }
+            }
+
+            if (shouldReset) {
+              accumulatedCall.arguments = newArgs;
+            } else {
+              accumulatedCall.arguments += newArgs;
+            }
           }
         }
       }
@@ -1562,7 +1590,7 @@ export class OpenAIContentGenerator implements ContentGenerator {
         }
       }
 
-      messageContent = textParts.join('');
+      messageContent = textParts.join('').trimEnd();
     }
 
     const choice: OpenAIChoice = {