Function: repairToolPairing() 

function repairToolPairing(messages): Message[];

Defined in: messages/index.ts:220

Repair tool use/result pairing issues in a message array.

This function handles BOTH types of orphans with POSITIONAL requirements:

  1. Orphaned tool_result blocks (those without a matching tool_use BEFORE them)
    • Causes: “function_response.name: Name cannot be empty” in Gemini
  2. Orphaned tool_use blocks (those without tool_result in IMMEDIATELY NEXT message)
    • Causes: “tool_use ids were found without tool_result blocks” in Claude

CRITICAL: Claude API requires tool_result to be in the IMMEDIATELY NEXT message after the assistant message containing tool_use. This function validates that positional requirement, not just existence anywhere in the array.

This is particularly useful after context compaction/summarization, which may remove messages and break tool_use/tool_result pairing.

Parameters

Parameter Type Description
messages Message[] Array of messages to repair

Returns

Message[]

New array with orphaned tool_use and tool_result blocks removed