Anthropic

{ "publicModel": "claude", "adapterKey": "anthropic", "upstreamModel": "claude-sonnet-5", "credentials": { "apiKey": "sk-ant-..." } }

Credentials: apiKey. version (the anthropic-version header) defaults to 2023-06-01 and rarely needs overriding.
Default transport: Messages API for text.
Reasoning: either anthropic_adaptive (the model picks its own depth; the request only carries an output_config.effort label) or anthropic_budget (thinking: { budget_tokens }, with a provider-side default budget per canonical level if the catalog doesn't override it) — see Reasoning. Models that expose both xhigh and max preserve them as distinct tiers; models such as Opus/Sonnet 4.6 declare max without inventing xhigh support.
Claude Opus 5 enables adaptive thinking upstream when thinking is omitted. The adapter sends thinking: { "type": "disabled" } when canonical reasoning resolves to none, preserving the gateway's provider-independent off semantics.
claude-opus-5-fast and claude-opus-4-8-fast are gateway aliases for Anthropic's research-preview fast mode. The adapter selects the base model, sends speed: "fast", and adds the required beta header. Anthropic account access is still required.
Native /v1/messages requests pass through with minimal translation; /v1/chat/completions and /v1/responses requests are rendered onto the same canonical reasoning/tool/format machinery as every other provider.
Catalog: src/adapters/anthropic/catalog.json.

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