fix(ai): use toolCallId for parallel tool execution tracking#11966
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delta575 wants to merge 2 commits intovercel:mainfrom
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fix(ai): use toolCallId for parallel tool execution tracking#11966delta575 wants to merge 2 commits intovercel:mainfrom
delta575 wants to merge 2 commits intovercel:mainfrom
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When tracking outstanding tool executions, use `toolCall.toolCallId` instead of `generateId()`. This fixes an issue where frameworks that override `generateId` for message grouping (returning the same ID for all tools in a request) would cause the `outstandingToolResults` Set to track only one tool. Problem: - Frameworks like @convex-dev/agent override `generateId` to return a constant `pendingMessageId` for message association purposes - This caused `outstandingToolResults.add(generateId())` to add the same ID multiple times, but Sets ignore duplicates - When the first tool completed and deleted the ID, the Set became empty - Stream closed prematurely, losing results from other tools Solution: - Use `toolCall.toolCallId` which is guaranteed unique per tool call from the LLM - This ensures each tool execution is tracked independently Test verification: - Test fails without fix: only 1 of 3 results captured - Test passes with fix: all 3 results captured Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Background
Split from #11907 per review feedback to separate from the close guard fix.
The generateId parameter serves a valid purpose: allowing frameworks to control message IDs for grouping. For example, @convex-dev/agent overrides it to return the same ID for all messages in a request:
However, generateId() was also being used internally to track outstanding tool executions via a Set. When a framework returns the same ID for message grouping, the Set tracks only one entry instead of N tools:
Tool A: outstandingToolResults.add("msg-123") → Set: {"msg-123"}
Tool B: outstandingToolResults.add("msg-123") → Set: {"msg-123"} (duplicate ignored)
Tool C: outstandingToolResults.add("msg-123") → Set: {"msg-123"}
Tool B completes: outstandingToolResults.delete("msg-123") → Set: {} (empty!)
attemptClose() sees empty set → closes stream prematurely
Tool A and C results are LOST
Summary
Use toolCall.toolCallId instead of generateId() for tool execution tracking.
toolCallId is unique per tool call from the LLM and is the correct identifier for tracking individual tool executions. This separates the concerns of message ID generation (user-controlled) from internal tool execution tracking (implementation detail).
Manual Verification
The included test deterministically reproduces the issue:
Also tested end-to-end with @convex-dev/agent and Gemini 2.5 Flash with 5+ parallel tool calls.
Checklist
pnpm changesetin the project root)Related Issues