Gemini 3 signs a tool call on its OpenAI-compatible endpoint
(extra_content.google.thought_signature) and refuses the next request
with a 400 when the call comes back without it, so every turn in which
the model called a tool failed. The Chat Completions client now keeps
the signature per call as the step's provider state and sends it back
with the call, to the model that signed it only.
An own server entered with Gemini's endpoint now also gets Gemini's
narrower tool schemas, which it refused before.
Maurice
22574a2270