Supabase plugin/mcp not working

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

I cant connect Supabase MCP/Plugin. It won’t authenticate. I have had them previously set up before but now they aren’t working.

Steps to Reproduce

Try to authenticate the supabase plugin

Expected Behavior

Login to authenticate and it should connect

Screenshots / Screen Recordings

Screenshot 2026-04-27 at 8.57.29 AM.png
Screenshot 2026-04-27 at 8.57.29 AM.png2816×1740 96.7 KB

Operating System

MacOS

Version Information

Version: 3.2.11 (Universal)
VSCode Version: 1.105.1
Commit: e9ee1339915a927dfb2df4a836dd9c8337e17cc0
Date: 2026-04-24T14:36:47.933Z
Layout: glass
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 25.3.0

For AI issues: which model did you use?

Any

Does this stop you from using Cursor

No - Cursor works, but with this issue

5

Hey, thanks for the report. The Unrecognized client_id error from api.supabase.com means Cursor is using a cached OAuth client registration from an old setup, and Supabase no longer recognizes that registration. It likely expired or was reset. So new auth requests get rejected right away.

You need to force Cursor to create a fresh registration. Try this:

  1. In MCP/Plugins settings, click Disconnect/Logout for Supabase. This should clear the stored OAuth client info.
  2. Completely remove the Supabase plugin.
  3. Close all Cursor windows and reopen Cursor.
  4. Install the plugin again and go through OAuth. This time it should do a new Dynamic Client Registration.

If step 1 isn’t available in the UI, or if you still get the same error after reinstalling, please send logs: go to View → Output, pick Cursor MCP in the dropdown (or the Supabase channel), then copy the output from when you click Authenticate until the error shows up. In the logs there should be a line Saving client information. If it’s missing, DCR isn’t starting, and that’s a bug on our side.

6

I still get the same error after doing those steps. . I cant see output under view tab?? Can you help me locate that please

7

I have the same problem

8

Hey, let’s go step by step.

@Andy_Wilkinson, to open Output on macOS:

  • Top menu View → Output, or use Shift+Cmd+U
  • If it won’t open from the menu, press Cmd+Shift+P, then type Output: Focus on Output View
  • Once the panel is open, there’s a dropdown in the top right for the log source. Select Cursor MCP and if there’s a separate channel like Supabase or plugin-supabase, copy logs from there too.

Then click Authenticate again and paste everything that shows up in the logs from the moment you click until the error. It’s especially important to see the line Saving client information. If it’s missing, Dynamic Client Registration isn’t starting, and that would be on our side.

A couple extra questions:

  • Are you behind a corporate proxy, VPN, or Zscaler right now? The OAuth callback cursor://... can get intercepted.
  • When you reinstalled, did you touch the ~/.cursor folder, or did you only remove the plugin via the UI?

@drippingfist, do you have the exact same Unrecognized client_id error, or different text? Also what Cursor version and OS? If you can, please share the MCP logs too: View → Output → Cursor MCP. That’ll help us confirm if it’s one bug or multiple.