How to Use Your Own API Key in Cursor IDE

Check the Base URL, key, account balance and model access. Use https://runapi.ai/v1 with your RunAPI key. An authentication error needs investigation; changing the URL alone does not guarantee a fix.

Cursor support states that BYOK with a custom Base URL in Agent or Composer requires a paid plan. A free account can save the settings but may be blocked when sending. Confirm your plan before subscribing to an API service.

Check Settings > Models and Cursor's API Keys documentation for supported models. The picker may display a name rather than its API ID; for example, GPT-5.6 Sol corresponds to gpt-5.6-sol. Availability depends on your Cursor plan and integration support.

Cursor subscription fees and RunAPI API usage are billed separately. BYOK does not replace the required Cursor subscription. Check current pricing and limits for both services; no fixed saving or unlimited usage is guaranteed.

Yes. One key works in Cursor, Claude Code, OpenClaw, and any OpenAI-compatible client, all drawing from the same balance.

Use https://runapi.ai/v1 for supported OpenAI API requests with your RunAPI key. Auto and Cursor's proprietary features do not route through this key.

Use only models and features supported by Cursor's API key integration. OpenAI-compatible syntax alone does not guarantee compatibility. Auto does not use your personal API key; Cursor's proprietary features use its own services.

Send a short test message, then check the matching model and usage record in your RunAPI dashboard. If Cursor shows "Free plans can only use Auto", check your Cursor plan's access to custom API keys.