# Anthropic

URL: https://docs.hanzo.ai/docs/guides/migrate/anthropic

> The Anthropic Messages API is served at POST /v1/messages: point the SDK or Claude Code at api.hanzo.ai with a Hanzo key as the bearer, and name a model as anthropic/claude-* or any other model in the catalogue.

Anthropic's API is `POST /v1/messages`, and Hanzo serves the same route at
`https://api.hanzo.ai/v1/messages`. The body you send today works unchanged. Two
things move: the host, and the key, which goes as a bearer token. Every Claude
model is in the catalogue as `anthropic/claude-*`, beside the other providers'
models and Hanzo's own, so one key reaches all of them through the same route.

## Start here

```bash
# the call you already make, at a different host, with a Hanzo key as the bearer
curl -sS https://api.hanzo.ai/v1/messages \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H 'anthropic-version: 2023-06-01' \
  -H 'Content-Type: application/json' \
  -d '{"model":"anthropic/claude-haiku-4.5","max_tokens":256,
       "messages":[{"role":"user","content":"summarise Q3"}]}'

# the names it accepts
curl -sS https://api.hanzo.ai/v1/models | jq -r '.data[].id' | grep '^anthropic/'
```

In the SDKs, set the base URL and pass the key as the auth token, the form that
sends a bearer:

```python
from anthropic import Anthropic
client = Anthropic(base_url="https://api.hanzo.ai", auth_token=os.environ["HANZO_API_KEY"])
```

```ts
import Anthropic from "@anthropic-ai/sdk";
const client = new Anthropic({ baseURL: "https://api.hanzo.ai", authToken: process.env.HANZO_API_KEY });
```

## Claude Code

Keep Claude Code. `hanzo --claude` starts it on your Claude plan with the Hanzo
toolset attached, so it can hand work to Enso and Kai. `hanzo --claude --cloud`
moves its own model calls onto Hanzo as well, sets `ANTHROPIC_BASE_URL` and the
bearer for that run, and names `enso-auto` unless you pass `--model`. Your
`~/.claude` is not edited. [Claude Code with Hanzo →](https://docs.hanzo.ai/docs/guides/coding/claude-code)

## Nouns

| Anthropic             | Hanzo                                                                                              |
| --------------------- | -------------------------------------------------------------------------------------------------- |
| `x-api-key: sk-ant-…` | `Authorization: Bearer <Hanzo key>`                                                                |
| `claude-sonnet-…`     | `anthropic/claude-…`, or any model in `GET /v1/models`                                             |
| Workspace             | Org: the key carries it                                                                            |
| Console usage         | `hanzo usage summary`, `hanzo console` (press `6`), [platform.hanzo.ai](https://platform.hanzo.ai) |

## What does not carry

**The model name gains a prefix.** A bare `claude-…` id is Anthropic's own
naming. Here the catalogue names the provider, `anthropic/claude-haiku-4.5`, so
the same key can also name `openai/…`, `google/…` or `enso-auto`.

**The key goes as a bearer.** Send it in `Authorization: Bearer`. That is what the
SDKs' `auth_token` option sends, and what `hanzo --claude --cloud` sets.