---
title: "Anthropic-compatible servers"
description: "Expose a server that speaks the Anthropic Messages API."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.noket.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Anthropic-compatible servers

Noket forwards both OpenAI- and Anthropic-shaped requests. Choose the protocol per upstream; a server
that speaks the Anthropic Messages API uses the `anthropic` protocol.

```bash
noket upstream add \
  --name local-anthropic \
  --protocol anthropic \
  --url http://127.0.0.1:8080 \
  --model my-model
```

## What changes with the `anthropic` protocol

| | `openai` | `anthropic` |
| --- | --- | --- |
| Path | `/v1/chat/completions` and related | `/v1/messages` |
| Key header | `Authorization: Bearer …` | `x-api-key: …` |
| Model discovery | `GET {base}/v1/models` | `GET {base}/v1/models` |

Probing for models uses `GET {base}/v1/models` regardless of protocol, because that is the endpoint
servers commonly expose. A server that does not implement it will fail the probe; save the upstream
anyway and enter model ids by hand.

## Custom headers

Some gateways need extra headers, for example a routing or organization header. There is no
command-line flag for them; add them in `config.toml`:

```toml
[[upstreams]]
name = "gateway"
protocol = "anthropic"
base_url = "https://gateway.internal"
headers = { "X-Route" = "team-a" }
models = ["claude-model"]
```

See the [configuration reference](https://docs.noket.dev/reference/config/) for every key.

## When to use which protocol

Match the server, not the client. If the server implements `/v1/messages`, use `anthropic`; if it
implements `/v1/chat/completions`, use `openai`. A proxy that translates between the two should be
configured with the protocol it exposes, and Noket will not translate anything on its own.

## Next

- [Create a model in the console](https://docs.noket.dev/console/models/add-model/)
- [Configuration file](https://docs.noket.dev/reference/config/)

Source: https://docs.noket.dev/connector/local-models/anthropic-compatible/index.mdx