[Bug]: Google Antigravity 400 missing thought_signature on historical tool calls (cockpit-tools)

[agentHits]

Client or integration

Codex App

Area

Provider adapter

Summary

When using google-antigravity (gemini-3.7-flash / thinking models) with subscriptions / accounts imported via the cockpit-tools integration module, multi-turn sessions with tool usage continuously crash with upstream HTTP 400 errors indicating that historical functionCall parts are missing the required thought_signature.

This error breaks and interrupts tasks repeatedly across different execution tools and multi-agent coordination steps:

• Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call 'default_api:exec' , position 133. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.
• Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call 'default_api:wait' , position 238. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.
• Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call 'default_api:collaboration__wait_agent' , position 262. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.

Expected behaviour:
The proxy should preserve and replay all thought_signature tokens for historical functionCall items across turns, context compaction, and multi-agent subtasks so that upstream Gemini Antigravity reasoning models accept the tool call history.

Reproduction

1. Import Google Antigravity account credentials via the cockpit-tools integration format (ocx account import google-antigravity --format cockpit-tools).
2. Start OpenCodex (v2.26.0) with google-antigravity configured.
3. In Codex App (Desktop), select google-antigravity/gemini-3.7-flash and start a multi-step task involving tool execution and agent coordination.
4. Execute several turns with tool invocations (default_api:exec, default_api:wait, default_api:collaboration__wait_agent).
5. As conversation history grows or is replayed (positions 133, 238, 262), upstream rejects the request with HTTP 400 due to missing thought_signature.

Version

2.26.0

Operating system

macOS 15.5

Provider and model

google-antigravity / gemini-3.7-flash

Logs or error output

Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:exec` , position 133. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.

Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:wait` , position 238. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.

Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:collaboration__wait_agent` , position 262. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.

Redacted configuration

{
  "providers": {
    "google-antigravity": {
      "authMode": "oauth"
    }
  }
}

Checks

• I searched existing issues and documentation.
• I removed secrets, tokens, account details, request credentials, and personal data.

[agentHits]

CC: @lidge-jun @Ingwannu @Wibias

Hi maintainers!

Could you please prioritize investigating and fixing this issue? Currently, running google-antigravity (specifically gemini-3.7-flash via subscriptions imported through cockpit-tools) in OpenCodex v2.26.0 is severely degraded / unusable for real workflows because any multi-turn session with tools quickly fails with HTTP 400 (Function call is missing a thought_signature in functionCall parts).

The issue reliably interrupts work across different tool calls in long-running tasks and agent workflows:

1. default_api:exec at position 133
2. default_api:wait at position 238
3. default_api:collaboration__wait_agent at position 262

It appears that when conversation turns are replayed (or after compaction / multi-agent turns), the replay store is not restoring or attaching the required thought_signature to historical functionCall items for this provider/credential scope, causing upstream Google Antigravity to reject subsequent requests.

Any fix or guidance on this would be greatly appreciated!

[lidge-jun]

리뷰 · 우선순위 68 / 80

cockpit-tools가 범인이 아님. 그거 계정 임포트 포맷임(ACCOUNT_IMPORT_FORMAT). 죽은 곳은 google-antigravity + thinking 모델의 툴 히스토리 리플레이임. 업스트림이 interleave thinking을 stateless로 돌려서, 예전에 나간 functionCall에 thought_signature가 없으면 400임. 리포터 문구가 그거임. default_api:exec 133, wait 238, collaboration__wait_agent 262. 첫 턴이 아니라 히스토리가 커진 다음임.

이미 있는 장치가 세 겹임. observeAntigravityReplay / applyAntigravityReplay가 name+args로 캐시함(#897). googleToolCallMetadataFromPart가 tool_call_start에 providerMetadata.google.thoughtSignature를 실음(#1735). 클라이언트가 extra_content를 안 메아리치면 src/responses/thought-signature-replay.ts가 call_id로 다시 붙임. 세 겹이 다 첫 emit에서 서명을 봤어야 함. 못 보면 히스토리 재조립(google.ts assistant toolCall 직렬화)이 빈 functionCall을 보냄.

지금 dev의 구멍은 두 개임. SSE에서 thought 파트랑 functionCall이 청크가 갈라지면 observeAntigravityReplay가 청크마다 pendingThoughtSig를 새로 만들어서 앞 청크 서명이 증발함. 같은 턴에 툴이 두 개면(exec + wait) 첫 콜에서 pendingThoughtSig = undefined로 지워서 둘째부터 빈 값임. #897 주석이 “다음 functionCall 하나랑 페어하고 짝 없는 건 버림”이라서 의도였음. 병렬 툴 턴이랑은 안 맞음.

extractSignature는 이미 thoughtSignature / thought_signature / extra_content.google.thought_signature를 봄. google.ts 파서는 part.thoughtSignature만 봄. 업스트림이 스네이크만 주면 메타데이터가 tool_call_start에 안 실림. 리플레이 캐시는 채워져도 히스토리 직렬화는 빈 값임.

점수는 68임. 2.26.0에서 Antigravity 툴 루프가 실제로 죽음. 80 아님. native-main 503(#2108/#2114)이랑은 다른 줄이고, 릴리즈 게이트도 아님. 2.27에 안 넣어도 됨.

해결방안은 드래프트 #2127 방향임. 스트림 턴 동안 pending을 청크 너머로 들고, 같은 턴 툴 전부 같은 thought 서명을 받게 하고, 파서도 스네이크를 읽게. 콤팩션/멀티에이전트가 메타데이터를 지우는 경로면 그 다음임. Closes #2125는 필드에서 멀티턴 툴 루프 한 번 보기 전엔 이름.

이 댓글은 grok-bot이 작성했습니다

[lidge-jun]

Fixed on dev by #2150, merged as 9a78015.

Verified present on the branch rather than assumed: git log origin/dev shows the merge commit above. These PRs target dev rather than main, so GitHub does not auto-close the linked issue — this closure is manual.

It ships in the next release cut from dev. Reopen if you still see it after updating.

[agentHits]

Update: Encountered this issue again on v2.28.0 (fresh turn, default_api:exec at position 6, and long conversation position 364):

Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:exec` , position 6. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.

Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:exec` , position 364. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.

Note on position 6: this can happen in fresh short turns if freeform tool calls (default_api:exec) or certain client history items are replayed without having their thought_signature resolved/re-attached from the store at serialization time.

[agentHits]

Additional reproduction log on v2.28.0:

Provider error 400: Antigravity invalid request: Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:exec` , position 381. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.

Follow-up PR opened: #2198 to handle matching unwrapped freeform/custom tool arguments ({ input: string } vs parsed functionCall args) in the replay cache.

[Ingwannu]

Reopening because the v2.28.0 reports show that #2150 did not cover the complete failure surface.

The earlier Grok review correctly identified the cross-chunk, parallel-call, and snake_case signature paths fixed by #2150. The new position-6 and position-381 reproductions point to a separate boundary: freeform/custom tool arguments can be represented to the client as { input: "<serialized JSON>" } while Antigravity replay observation stores the parsed function arguments. If those representations do not converge before replay lookup, the signature cannot be restored even in a short history.

I am reviewing #2198 against the current dev head now. I will keep this issue open until the exact PR head has a regression covering the full observe -> client-visible custom tool -> next-request parse -> Google serialization round trip, and all relevant CI is green. A local lookup-only test is not sufficient to close this again.