Module signature 

Upstream signatures carried by the client in its own protocol’s field.

A Gemini thoughtSignature or a Claude thinking signature is opaque to the client and verified by the upstream that issued it, so the gateway keeps nothing: it hands the native value to the client in the field its protocol already has for reasoning state (a Claude thinking block’s signature, a Responses reasoning item’s encrypted_content), and reads it back from there on the next turn. The value is not encrypted or wrapped; only a short prefix names its source, so a later turn can put it back where that upstream expects it, or strip it when the conversation has moved to an upstream that would reject it.

• gemini:<signature> is the signature of a Gemini thought part. The carrier’s text is the part’s text, and the pair replays as one {thought: true, text, thoughtSignature} part: the only shape a Claude model behind Antigravity accepts. An empty signature marks thought text the upstream did not sign; it replays as nothing.
• gemini-next:<signature> is the signature of the Gemini part that the carrier precedes in the client’s history (a functionCall, or a generated image), which has no field of its own for it. The carrier has no text.
• claude:<signature> is a Claude thinking block’s signature, shown to a client whose reasoning field is not a Claude one.

A Claude client’s own Claude signature carries no prefix: it is native there, and a Claude request routed to Anthropic as it is must not change. Chat clients carry signatures in reasoning_details, whose format names the source instead (see reasoning_details).

Enums

Carried

A carried signature, with its source prefix removed.

Constants

CLAUDE

A Claude thinking block’s signature.

GEMINI

A Gemini thought part’s signature.

GEMINI_NEXT

A Gemini signature for the part after the carrier.

Functions

claude

The carried form of a Claude thinking signature.

gemini_next

The carried form of the signature of the Gemini part after the carrier.

gemini_thought

The carried form of a Gemini thought part’s signature; None marks an unsigned thought.

is_carried

True for a value with any source prefix gproxy adds.

is_gemini

True for a value that carries a Gemini signature in any form.

without_carried_reasoning

A Responses request (or input token count) body without the reasoning items whose encrypted_content carries another upstream’s signature; None when it holds none. This is for a request that reaches a Responses upstream as it is, without conversion: that upstream decrypts its own ciphertext only, and refuses a Claude or Gemini signature it finds there.