Gemini API 400: functionResponse.name cannot be empty when proxying via antigravity

[jveko]

Description

When using clients like Amp that proxy requests through CLIProxyAPI to Google's Gemini API via the antigravity translator, requests fail with a 400 error:

* GenerateContentRequest.contents[2].parts[0].function_response.name: Name cannot be empty.
* GenerateContentRequest.contents[2].parts[1].function_response.name: Name cannot be empty.
...

Steps to Reproduce

1. Use Amp (or any client) connected to CLIProxyAPI's antigravity endpoint
2. Trigger a multi-tool-call interaction (e.g. the finder/search agent)
3. The model returns multiple functionCall parts, client executes them and sends back functionResponse parts
4. The proxy forwards functionResponse parts with empty name fields to Gemini API
5. Gemini rejects the request with 400 INVALID_ARGUMENT

Root Cause

Incoming requests from clients include functionResponse parts without populating the name field. The proxy's fixCLIToolResponse in the antigravity translator forwards them as-is without resolving the name from the corresponding functionCall parts in the preceding model content.

Additionally, ConvertOpenAIResponsesRequestToGemini scans the raw input array for matching function_call items by call_id, but may fail to find matches since the function calls may not be present as top-level items in the input.

Expected Behavior

The proxy should backfill empty functionResponse.name from the corresponding functionCall.name before forwarding to Gemini.

Environment

• CLIProxyAPI antigravity translator
• Google Gemini API (daily-cloudcode-pa.googleapis.com)
• Client: Amp (finder/search subagent)

[jveko]

A reference implementation is available in PR #2103. Since internal/translator changes are restricted, the maintenance team can review and apply the fix directly.

[jveko]

Closing — already fixed in #2076 (v6.8.52).