Add the following to your settings.json:

  "assistant": {
    "version": "2",
    "default_model": {
      "provider": "anthropic",
      "model": "claude-3-5-sonnet-20240620"
    }
  }
  

Once this is done, you should be able to use Anthropic if you have an API key. (This was available before today's announcement and still works today as of Zed 0.149.3)