ADR-0004 — Anthropic's temperature rides extra_body

Context

AnthropicProvider.generate() originally passed temperature directly to client.messages.create(temperature=...), mirroring the OpenAI provider. Manually exercising the CLI's ask command against the installed anthropic package (1.7.0) raised TypeError: Messages.create() got an unexpected keyword argument 'temperature' — confirmed by inspecting the installed SDK's actual signature, which no longer exposes temperature as a typed parameter (its generation controls have moved toward an output_config object with an effort field instead). This was caught by manually running the CLI end to end, not by the mocked provider unit tests — mocking the SDK client verifies groundedrag builds the call it intends to make correctly, not that the real SDK still accepts that call.

Decision

Pass temperature via extra_body={"temperature": temperature}, the SDK's documented escape hatch for body fields not in its typed surface. Verified against the real API (with an invalid key, to confirm the request reaches the server and fails on auth rather than on request shape): the call now returns AuthenticationError, not TypeError.

Consequences

• If the Anthropic API stops accepting temperature in the request body at all (not just in the typed SDK signature), this call will need to change again — there is no way to detect that ahead of time other than the API's own error message.
• This is a reminder that mocked SDK tests (tests/test_providers.py) verify groundedrag's request-building logic, not the vendor SDK's current contract. A lightweight, opt-in "real API" smoke test (skipped unless an API key is present in the environment) would catch this class of drift automatically instead of relying on someone noticing during manual use — worth adding in a follow-up rather than deferred indefinitely.