OptionaldataEncrypted payload of a redacted_thinking block.
OptionaloriginWhere the signature validates, when the provider scopes it (Gemini: endpoint plus model). A driver drops a block whose origin differs from the request it is building.
The driver family that produced the block, e.g. 'anthropic' or 'gemini'.
OptionalsignatureThe provider signature that must be replayed with the block.
OptionaltextThe reasoning text (thinking, thought), or the visible part's text (signed_text).
Provider-opaque reasoning from one assistant turn, kept so the turn can be replayed exactly.
Anthropic asks for a tool-use turn's thinking blocks to come back unchanged, signatures intact, or the model loses its reasoning between tool calls; Gemini signs thought and text parts the same way. Only the driver that produced a block reads it — every other driver ignores blocks whose
provideris not its own, so a conversation that fails over to another provider stays valid. Never shown to the model as text and never read by the agent loop.