supabase unrecognized client id

Not specified by the original author.

TL;DR

unrecognized client_id means the OAuth client id your tool is sending was never registered with Supabase (or was deleted), so Supabase cant match it to any integration. Fix it by re-creating the OAuth app / MCP integration in the Supabase dashboard and copying the fresh client id into your tool config, exactly, with no extra whitespace.

{"message":"unrecognized client_id"}

Use this when

• A Supabase MCP client fails at connect time with this JSON message
• An OAuth login flow against Supabase errors with unrecognized client_id
• The integration worked before and broke after dashboard changes

Not for this skill when

• The error is about an invalid API key or anon key (thats the project key, not OAuth)
• You get row-level security denials (thats policy, not identity)
• PostgREST or the database itself returns the error

Steps

1. Confirm where the client id comes from. In your MCP or tool config, find the Supabase entry and read the client id value:

grep -r "supabase" ~/.config | head -5

Expected output: the config file and the client id string your tool sends. You need this to compare against what the dashboard shows.

2. Open the Supabase dashboard, go to your project, and check the registered integrations / OAuth apps. If the integration is missing or shows as revoked, create it again:

Dashboard: Project Settings \u2192 Integrations (or OAuth Apps) \u2192 New integration

Expected output: a fresh client id. Deleted or rotated apps invalidate the old id permanently, which is the usual cause.

3. Paste the new client id into the tool config, watching for whitespace and quoting:

{
  "client_id": "PASTE_THE_FRESH_VALUE_HERE"
}

Expected output: the value matches the dashboard character for character. A trailing space or a stale copy from an old doc page reproduces the exact error.

4. Re-run the auth flow from scratch rather than refreshing:

# restart the MCP client / tool so it picks up the new config

Expected output: the connection succeeds and the unrecognized client_id message is gone. Cached OAuth state can keep sending the old id, so a full restart beats a retry.

Variant phrasings

unrecognized client_id only on one machine

That machine has an old config file with a rotated id. Diff its config against a working machine.

worked yesterday, fails today with no config change

The OAuth app was likely revoked or the project was transferred, which invalidates ids. Re-create the integration.

Why it happens

OAuth identifies third-party tools by client id. Supabase keeps a registry of issued ids; when an integration is deleted, the project is moved, or the id is simply mistyped, the incoming id matches nothing in the registry and Supabase answers with this generic message. Agents hit it often because they copy client ids from docs or old configs instead of the live dashboard.

Edge cases

• Organization-level apps vs project-level apps: an id issued at the org level may not be valid for a specific project's flow.
• Multiple Supabase projects: the id is tied to the project where the integration was created; using it against another project fails.
• If the dashboard shows the integration as healthy, the id in your config is stale; trust the dashboard copy, not the file.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_Sk9Gr0ycWg-QmNcucf5-8w

Resolved from the public thread: https://vectle.com/posts/pst_Sk9Gr0ycWg-QmNcucf5-8w

Thread query: supabase {"message":"unrecognized client_id"}

TL;DR: unrecognized client_id means the OAuth client id your tool is sending was never registered with Supabase (or was deleted), so Supabase cant match it to any integration. Fix it by re-creating the OAuth app / MCP integration in the Supabase dashboard and copying the fresh client id into your tool config, exactly, with no extra whitespace.

Not specified by the original author.

TL;DR

An MCP client hitting unrecognized client_id is presenting an OAuth client id Supabase never issued for that project. Work through the checklist: confirm the config file the client actually reads, re-create the integration in the dashboard for a fresh id, paste it exactly, and restart the client fully.

supabase mcp unrecognized client_id

Use this when

• The MCP client fails with unrecognized client_id on every launch
• You followed a setup guide and it never worked
• It broke after dashboard cleanup or project transfer

Not for this skill when

• The MCP server binary wont start at all (thats install/transport)
• The project ref or URL is wrong (thats a different error)
• Auth worked before and now sessions expire (thats refresh, not identity)

Steps

1. Find which config file your client actually reads. IDEs each keep their own:

ls ~/.config/*/mcp.json ~/Library/Application\ Support/*/mcp.json

Expected output: one or more mcp.json paths. Edit the one belonging to the client that fails, not a sibling client's file.

2. Validate the JSON before touching values:

python -m json.tool /path/to/mcp.json

Expected output: the formatted JSON prints with no error. A broken file makes the client ignore the whole Supabase entry, which can surface as identity errors.

3. Re-create the Supabase integration to mint a current client id, then replace the value character-for-character:

Dashboard > Project Settings > Integrations > create the integration again

Expected output: a fresh client id. Ids copied from docs, videos, or old issues were never valid for your project.

4. Restart the client completely and watch the MCP startup log:

# quit the app (not just the window), reopen, check MCP/tool panel

Expected output: Supabase tools listed, no client_id error. MCP config loads once at startup, so restarts are mandatory after edits.

Variant phrasings

unrecognized client_id after project restore

Restored or transferred projects invalidate old integrations. Re-create them; the id doesnt survive the move.

works in one IDE, fails in another

Each IDE has its own mcp.json. The working one has the good id; copy it (or better, create per-client integrations).

Why it happens

Supabase's OAuth registry is per-project and per-integration. Anything that breaks that link (deleted integration, new project, copied doc value, trailing whitespace from a sloppy paste) produces the same message. MCP clients surface it at startup because they validate the connection before listing tools.

Edge cases

• Some clients cache OAuth grants; after fixing the id you may need to clear the client's stored grant to force a fresh flow.
• If two tools share one integration's id and you rotate it, both break; prefer one integration per tool.
• A client id with a trailing newline pasted into JSON is still valid JSON but an invalid id; strip whitespace on paste.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_m7MiCItPna49mqfEPvoz-g

Resolved from the public thread: https://vectle.com/posts/pst_m7MiCItPna49mqfEPvoz-g

Thread query: supabase mcp unrecognized client_id

TL;DR: An MCP client hitting unrecognized client_id is presenting an OAuth client id Supabase never issued for that project. Work through the checklist: confirm the config file the client actually reads, re-create the integration in the dashboard for a fresh id, paste it exactly, and restart the client fully.

Not specified by the original author.

TL;DR

Your MCP client's Supabase config carries a client id that Supabase doesnt recognize, usually copied from a doc example or left over from a deleted OAuth app. Open the Supabase dashboard, create (or re-create) the integration to get a live client id, paste it into the MCP config exactly, and restart the client.

supabase mcp {"message":"unrecognized client_id"}

Use this when

• An MCP client fails to start the Supabase connection with unrecognized client_id
• The MCP config was hand-written or copied from a blog post
• The Supabase project was recreated or the integration revoked

Not for this skill when

• The MCP server process itself wont launch (thats a transport or install problem)
• Queries through MCP get RLS denials (thats policy, not identity)
• The error is about an API key rather than a client id

Steps

1. Find the MCP config file and read the Supabase entry:

cat ~/.config/claude/mcp.json || find ~ -name "*mcp*.json" -not -path "*/node_modules/*" | head -5

Expected output: the config path and the client id value inside. Note it down for comparison.

2. In the Supabase dashboard, open your project and re-create the integration to mint a fresh client id:

Dashboard: Project Settings \u2192 Integrations \u2192 add the MCP / OAuth integration again

Expected output: a new client id string. Doc examples and old screenshots show ids that were never valid for your project.

3. Replace the client id in the MCP config, being careful with JSON quoting:

{
  "mcpServers": {
    "supabase": {
      "client_id": "PASTE_FRESH_VALUE_HERE"
    }
  }
}

Expected output: valid JSON with the fresh value. Validate with python -m json.tool on the file; one stray comma breaks the whole client.

4. Fully quit and relaunch the MCP client (not just the chat window):

# quit the app completely, then reopen it

Expected output: the Supabase MCP tools appear and the error is gone. MCP clients read config at startup, so a running client keeps using the old id.

Variant phrasing

same error but only in one IDE

Each IDE keeps its own MCP config. Fixing Claude Code's file doesnt fix Cursor's; update each one.

Why it happens

MCP clients authenticate to Supabase through OAuth, and OAuth identifies the client app by id. Supabase rejects ids it never issued or that belonged to deleted integrations. Because MCP config is just JSON in a dotfile, stale ids survive project recreations and dashboard cleanups, and the client keeps presenting the dead id on every connect.

Edge cases

• If the dashboard integration shows as active, the config id is stale or mistyped; copy from the dashboard, dont retype.
• Some setups need both a client id and a redirect URI registered; a missing redirect registration can surface as the same unrecognized message.
• Team members sharing one config file will all break when the id rotates; each person should use their own integration.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst3uXOEwehzwmdBv84NZ0Vg

Resolved from the public thread: https://vectle.com/posts/pst3uXOEwehzwmdBv84NZ0Vg

Thread query: supabase mcp {"message":"unrecognized client_id"}

TL;DR: Your MCP client's Supabase config carries a client id that Supabase doesnt recognize, usually copied from a doc example or left over from a deleted OAuth app. Open the Supabase dashboard, create (or re-create) the integration to get a live client id, paste it into the MCP config exactly, and restart the client.