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CodeTracked since May 19, 2026

Fix dropped function-response events by restoring missing IDs in adk-go tool-call deserialization

Google adk-go PR #690 fixes a bug where `aiplatformToGenaiContent` failed to copy the `Id` field from `FunctionCall` and `FunctionResponse`, which caused function-response events to be silently dropped in multi-invocation tool-calling sessions that rely on non-empty IDs. A round-trip unit test was added to prevent the regression.

aiplatformToGenaiContentcreateAiplatformpbContentFunctionCallFunctionResponse

What Happened

  • Google adk-go PR #690 fixes a bug where `aiplatformToGenaiContent` failed to copy the `Id` field from `FunctionCall` and `FunctionResponse`, which caused function-response events to be silently dropped in multi-invocation tool-calling sessions that rely on non-empty IDs. A round-trip unit test was added to prevent the regression.
  • Google adk-go PR #690 fixes a bug where `aiplatformToGenaiContent` failed to copy the `Id` field from `FunctionCall` and `FunctionResponse`, which caused function-response events to be silently dropped in multi-invocation tool-calling sessions that rely on non-empty IDs. A round-trip unit test was added to prevent the regression.
  • 1 evidence item attached for review.

What is Different

Before

Scattered source updates, isolated context, and manual follow-up across multiple feeds.

Now

Aligned deserialization with existing serialization behavior by populating `Id` in `aiplatformToGenaiContent` for both `FunctionCall` and `FunctionResponse`, and added a round-trip test to lock in correct ID handling in future changes.

Why Track This

Why It Matters

Applications using adk-go tool calling will stop losing function responses during multi-invocation flows, so automated tool workflows can continue without silent drops and no need for extra retry logic. The fix restores ID propagation from serialized protobuf message parts to match the expected ID-based event matching path; teams should watch whether any other tool-call protobuf fields still bypass ID mapping in similar conversion paths and confirm behavior after merge and rollout.

Impact

Applications using adk-go tool calling will stop losing function responses during multi-invocation flows, so automated tool workflows can continue without silent drops and no need for extra retry logic. The fix restores ID propagation from serialized protobuf message parts to match the expected ID-based event matching path; teams should watch whether any other tool-call protobuf fields still bypass ID mapping in similar conversion paths and confirm behavior after merge and rollout.

What To Watch Next

  • Watch whether aiplatformToGenaiContent becomes a repeated pattern.
  • Track follow-up changes around Tool Calling.
  • Compare future signals against this evidence trail.
  • Re-check risk flags: verify_id_fields_in_other_tool_message_paths, monitor_multi_invocation_sessions_after_merge.
Open Topic TimelineOpen Technical EventOpen Original Sourceverify_id_fields_in_other_tool_message_paths / monitor_multi_invocation_sessions_after_merge / confirm_no_future_regression_in_aiplatform_to_genai_conversion

Supporting Evidence

GITHUB PULL REQUESTHigh Trust

google/adk-go PR #690: fix(session/vertexai): populate FunctionCall and FunctionResponse IDs…

`aiplatformToGenaiContent` was not copying `Id` from `FunctionCall` and `FunctionResponse` protobuf parts during deserialization, so tool-call matching could drop events in multi-invocation sessions.