Cursor not using my OpenAI API key — requests still go to api2.cursor.sh

Discussions
1

I registered my OpenAI API key in Cursor Settings → Models. It shows active and persists across restarts. However, when I use the chat feature, all requests go to api2.cursor.sh (or api3.cursor.sh) instead of api.openai.com. I can successfully call api.openai.com via curl through my corporate proxy, so the key and proxy are functional. Cursor still falls back to Cursor backend and shows “Get Cursor Pro…” banner.

Actions I performed:

  • Registered OpenAI API key in Settings → Models
  • Verified curl to https://api.openai.com/v1/models through proxy works
  • Cleared CacheStorage & Local Storage under %APPDATA%\Cursor\
  • Launched Cursor with --proxy-server and set HTTPS_PROXY
  • Enabled ELECTRON_ENABLE_LOGGING and NODE_DEBUG
  • Collected Developer Tools Network screenshot and Console logs

Please advise:

  1. Which exact logs/files should I provide to diagnose why Cursor does not route model calls to api.openai.com?
  2. Is there any hidden flag, config or registry key that forces Cursor to use api2.cursor.sh despite a valid user API key?
  3. Why would Cursor’s internal validation treat proxy-connected api.openai.com as invalid while curl works?

Environment:

  • Cursor version: 2.0.69 (Electron)
  • OS: Windows 10/11
2

hi @user1131 this is expected behavior as all AI requests go through our servers.
Could you post a full separate Bug Report with more info Create Bug Report

Also add a Request ID with privacy disabled so we can look into the details? https://docs.cursor.com/troubleshooting/request-reporting

3

Hi, thank you for your response.

I understand that all AI requests go through Cursor’s servers by design.
However, even though I have successfully registered my own OpenAI API key and verified that it works (requests to api.openai.com respond correctly through our proxy), Cursor still shows the message:

“Get Cursor Pro for more Agent usage, unlimited Tabs, and more.”

Could you please clarify why this message appears even when I’m using my own OpenAI key?
I want to make sure I’m not limited by Cursor’s Pro usage when my requests are billed directly to my OpenAI account.

4

We do require a Pro subscription for usage of 3rd party API Keys in Agent mode. You can use Ask mode without Pro subscription.

5

Request Id : 76b37000-b288-4c47-9542-d264ec4f9868

6

Do you have an active Pro subscription?

7

No, I don’t currently have an active Pro subscription. I’m using the free plan with my own OpenAI API key.

I’d like to use the Agent mode using my own OpenAI API key.

8

We do require for Agent usage a Pro subscription, even if you use your own API key, as the AI calls go through our servers and are processed using Cursor services like indexing etc additional to pure AI inference.