Cursor

Cursor is a closed-source IDE that supports a custom OpenAI base URL for its chat/composer surface. Cursor calls that URL from its own servers, so rapid-mlx has to be reachable over public HTTPS, behind an API key.

Quick start

Needs: Cursor, a public HTTPS tunnel to your Mac's port 8000, and an API key. Cursor sends custom-model requests from its own servers, so it cannot reach localhost.

$ export RAPID_MLX_API_KEY="$(openssl rand -hex 24)"
$ rapid-mlx serve qwen3.6-35b-4bit             # uses RAPID_MLX_API_KEY
# expose port 8000 over HTTPS with a tunnel, then:
$ rapid-mlx launch cursor --server-url https://<your-tunnel-host>

Then pick the model in Cursor's model dropdown and send a chat message. A reply means it works.

Install

Download from cursor.com (closed-source vendor binary).

Config

Cursor routes custom-model (BYOK) requests through its own backend, so the URL you give it must be reachable from the internet over HTTPS. A tunnel that forwards to port 8000 on your Mac works. Never expose a server without a key: start it with one, and rapid-mlx launch cursor refuses to run without RAPID_MLX_API_KEY.

$ export RAPID_MLX_API_KEY="$(openssl rand -hex 24)"
$ rapid-mlx serve qwen3.6-35b-4bit          # serve reads RAPID_MLX_API_KEY
$ rapid-mlx launch cursor --server-url https://<your-tunnel-host> --dry-run
$ rapid-mlx launch cursor --server-url https://<your-tunnel-host>

launch cursor writes Cursor's user settings.json (~/Library/Application Support/Cursor/User/), appending /v1 to the URL and keeping your other settings. It rejects localhost, private addresses and plain HTTP before writing anything.

Run

With the server and tunnel up, open Cursor and pick the model from the model dropdown. Chat and composer requests then go through the tunnel to your Mac.

Gotchas

• Cursor CLI's agent path routes exclusively through Cursor's backend. Per Cursor's community forum + docs, the CLI/agent path is not integrable at a custom endpoint (the IDE chat/composer is), so the integration matrix (test_agents_matrix.py) has no Cursor cell. Source: tests/integrations/README.md.
• Model dropdown may hide unknown aliases. Cursor validates model names against its internal catalog; if a rapid-mlx alias doesn't show, pick default which always resolves to whatever the server booted.

See also