n8n - 💡(How to fix) Fix Official Supabase Node Fails with "Authorization failed" - HTTP Request and Community Node Work (n8n 2.20.9)

Bug Description

The official n8n Supabase node fails during credential testing with error: "Authorization failed - please check your credentials". The same credentials work correctly with the HTTP Request node (using only apikey header), the community node (n8n-nodes-supabase-advanced), and direct curl from the server.

To Reproduce

1. In n8n, go to Credentials → New Credential
2. Select "Supabase API" (official node)
3. Enter Host: https://your-project.supabase.co
4. Enter Service Role Secret: service_role key
5. Click "Test Connection" or "Save"
6. Error appears immediately: "Authorization failed - please check your credentials"

Expected behavior

The credential test should pass with a valid service_role key and show "Connection tested successfully".

Debug Info

From n8n logs during credential testing:

Authorization failed - please check your credentials Authorization failed - please check your credentials The connection cannot be established, this usually occurs due to an incorrect host (domain) value Authorization failed - please check your credentials

The credentials work correctly with:

HTTP Request node (using only apikey header) Community node (n8n-nodes-supabase-advanced) Direct curl from server

Operating System

Ubuntu (running on VPS via Docker)

n8n Version

2.20.9

Node.js Version

v24.14.1

Database

SQLite (default)

Execution mode

main (default)

Hosting

Self-Hosted n8n