Claude Desktop is Anthropic's desktop client. It has a built-in "third-party inference" option, so once you point its gateway at CrossModel you can use the whole catalog right from the desktop app.

Quickstart

Claude Desktop is configured entirely through its UI — no config files or environment variables.

1. Create an API key

Sign in to the Console and create a key that starts with cm- on the API Keys page. The key is shown only once, so copy it somewhere safe.

2. Enable Developer Mode

Open Claude Desktop and go to Help → Troubleshooting in the menu bar, then choose Enable Developer Mode to unlock the developer menu.

3. Configure third-party inference

From the menu bar, go to Developer → Configure Third-Party Inference… and fill in:

Click Apply locally to save.

4. Restart and pick the gateway

Quit Claude Desktop completely, reopen it, and choose Continue with Gateway on launch.

5. Choose a model

Pick a CrossModel model from the model selector and start chatting.

How it works

By default Claude Desktop connects to Anthropic's service. Once third-party inference is configured, every request from the desktop app goes to CrossModel's /v1/messages endpoint, authenticated with your cm- key via the bearer scheme.

Set the gateway base URL to https://api.crossmodel.ai — without a trailing /v1. The client appends /v1/messages for you.

Choosing models

Once connected, the model selector lists the models currently available on CrossModel. See the full list in the model catalog.

Troubleshooting