# Anthropic

> Configure anthropic deployments and understand provider-specific behavior.

URL: https://boelabs.com/en/docs/ai-gateway/providers-anthropic
Language: English

## Configure a deployment

Send this body to `POST /admin/deployments` with an operator credential. Replace the example
credentials and choose a model available to your provider account. See
[Creating deployments](https://boelabs.com/docs/ai-gateway/creating-deployments) for the shared configuration fields.

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

## Behavior and limitations

- **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](https://boelabs.com/docs/ai-gateway/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.
- **Signed thinking round-trips on `/v1/responses`.** When the request includes
  `reasoning.encrypted_content`, each turn's content (thinking, text and tool calls, in order) is
  sealed into a `reasoning` item that standard clients replay, and the next request sends the turn
  back exactly as Claude returned it. On `/v1/messages` the blocks stay native, in Claude's order.
  See
  [Provider-specific fields](https://boelabs.com/docs/ai-gateway/provider-specific-fields#anthropic-thinking-blocks-message-bound).
- 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.
- **Prompt caching is automatic on `/v1/chat/completions` and `/v1/responses`.** The adapter sends
  Anthropic's top-level `cache_control: { "type": "ephemeral" }` (5-minute TTL), so repeated prefixes
  are cached as they are on OpenAI and Gemini and reported in `cached_tokens`. To control caching
  yourself, use `/v1/messages`: those requests are sent with exactly the `cache_control` you write,
  or none.
- Models that declare `capabilities.strictTools: true` preserve Anthropic's native top-level
  `strict: true` tool flag. Native `output_config.format` is schema-adherent and is treated as strict
  structured output by the gateway.
- Anthropic compiles strict tool schemas and `json_schema` response formats from a subset of JSON
  Schema and rejects constraints outside it (`maxItems`, `minLength`, `minimum`, …) that OpenAI's
  strict mode accepts. For `/v1/chat/completions` and `/v1/responses` requests the adapter keeps
  the supported keywords and moves the rest into the field's `description`, as Anthropic's SDKs do;
  clients keep validating against their original schema. Native `/v1/messages` tools are sent as
  written.
- Catalog: `src/adapters/anthropic/catalog.json`.

## Next steps

- [Messages](https://boelabs.com/docs/ai-gateway/messages) — the native Anthropic-compatible contract.
- [Reasoning](https://boelabs.com/docs/ai-gateway/reasoning) — `anthropic_adaptive` / `anthropic_budget` in detail.