Status Code

Detailed Explanation

Status Code is a three-digit number that a Server sends back with every HTTP Request response. It tells your Frontend whether the request succeeded, failed, or needs something else — and gives a specific reason why.

Status codes are grouped by their first digit:

2xx — Success:

• 200 OK: Request worked, data returned
• 201 Created: A new resource was created (e.g., a new post saved to the Database)
• 204 No Content: Request succeeded but nothing to return

4xx — Client Error (your app sent something wrong):

• 400 Bad Request: Malformed data (missing fields, wrong format)
• 401 Unauthorized: No auth token or it's expired — user needs to log in
• 403 Forbidden: User is authenticated but doesn't have permission (often RLS)
• 404 Not Found: The Endpoint or resource doesn't exist
• 409 Conflict: Duplicate entry or version conflict

5xx — Server Error (something broke on the server):

• 500 Internal Server Error: The Server crashed — check Edge Function logs or Supabase logs

You'll see status codes in the Network Tab of your DevTools. When Debugging, the status code is your first clue: a 401 means fix Authentication, a 403 means fix RLS policies, a 500 means check server logs. Claude Code can help you interpret any status code and suggest the right fix.

Status codes appear in every HTTP Response and are visible in the Network Tab. A 403 often means a Permission issue from an RLS Policy, while an empty 200 response suggests RLS is silently blocking data.