PGRST301
what this Supabase data API error means
How it shows up
Expected 3 parts in JWT; got 1
What it means
The token sent in the Authorization header could not be decoded or is not valid, so the API rejected the request with HTTP 401.
The usual cause in an AI-built app
AI-generated fetch calls often build the header as Bearer plus a token variable that is still empty or undefined, so the API receives a broken token. Mixing keys from two different Supabase projects gives the same kind of rejection.
Check this first
In the browser Network tab, open the failing request and read its Authorization header: it should be Bearer followed by one long token that contains two dots.