Set up Anthropic

Configure an Anthropic provider in Aperture so your team can access Claude models through your tailnet. Anthropic uses the x-api-key authorization type and the anthropic_messages compatibility flag, which differ from the defaults.

Prerequisites

Before you begin, you need:

• An Aperture instance accessible from your device. Refer to get started with Aperture if you have not set this up.
• An Anthropic API key.

Configure the provider

Add Anthropic as a provider in your Aperture configuration:

{
  "providers": {
    "anthropic": {
      "baseurl": "https://api.anthropic.com",
      "apikey": "<your-anthropic-key>",
      "authorization": "x-api-key",
      "models": ["claude-sonnet-4-6", "claude-opus-4-7", "claude-haiku-4-5"],
      "compatibility": {
        "anthropic_messages": true
      }
    }
  }
}

The authorization field is set to x-api-key because Anthropic uses the x-api-key header instead of a bearer token. The anthropic_messages flag tells Aperture to use the Anthropic message format instead of the default OpenAI chat completions format. Refer to the provider compatibility reference for the full list of flags.

After configuring the provider:

1. Grant model access to the users or groups that need these models.
2. Set up LLM clients to connect coding tools through Aperture.

Verify the provider

The best way to verify a connection to a specific model is to send a test request through the Models tab of the Aperture dashboard.

1. Open the Aperture dashboard and select the Models tab.
2. Find the model you want to test in the list of configured models. If the model is not listed, check your provider configuration and ensure the model name is correct.
3. Select the Play icon to the left of the model name to send a test request. If the request succeeds, the icon changes to a green check mark. If it fails, the icon changes to a red "X".

This sends a request from your web browser to the tailnet to verify that Aperture can successfully route requests to the model through the configured provider and that your user account has the necessary permissions to access the model.