The x-anthropic-billing-header block in the Claude system array is
client-internal metadata and should not be forwarded to the Gemini
upstream as part of systemInstruction.parts.
Proxy-generated thinking blocks may carry hex hashes or other non-Claude
signatures (e.g. "d5cb9cd0823142109f451861") from Gemini responses. These
are now discarded alongside empty-signature blocks during the strip phase,
before validation runs. Valid Claude signatures always start with 'E' or 'R'
(after stripping any cache prefix).
Thinking blocks with empty signatures come from proxy-generated
responses (Antigravity/Gemini routed as Claude). These should be
silently dropped from the request payload before forwarding, not
rejected with 400. Fixes 10 "missing thinking signature" errors.
Antigravity wraps empty thinking text into a prompt-caching-scope
object that omits the required inner "thinking" field, causing 400
"messages.N.content.0.thinking.thinking: Field required" when Claude
Max requests are routed through Antigravity in bypass mode.
Raise the local bypass-signature ceiling so long Claude thinking signatures are not rejected before request translation, and keep the oversized-signature test cheap to execute.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
delegate schema sanitization to util.CleanJSONSchemaForGemini and drop the top-level eager_input_streaming key to prevent validation errors when sending claude tools to the gemini api
When a Claude assistant message contains [text, tool_use, text], the
Antigravity API internally splits the model message at functionCall
boundaries, creating an extra assistant turn between tool_use and the
following tool_result. Claude then rejects with:
tool_use ids were found without tool_result blocks immediately after
Fix: extend the existing 2-way part reordering (thinking-first) to a
3-way partition: thinking → regular → functionCall. This ensures
functionCall parts are always last, so Antigravity's split cannot
insert an extra assistant turn before the user's tool_result.
Fixes#989
Emit signature only when non-empty in both streaming content_block_start
and non-streaming thinking blocks. Avoids turning 'missing signature'
into 'empty/invalid signature' which Claude clients may reject.
Apply SanitizeFunctionName on request and RestoreSanitizedToolName on
response for: gemini/claude, gemini/openai/chat-completions,
gemini/openai/responses, antigravity/openai/chat-completions,
gemini-cli/openai/chat-completions.
Also update SanitizedToolNameMap to handle OpenAI format
(tools[].function.name) in addition to Claude format (tools[].name).
