How to fix a 403 Error on Actions and API Routes | Next.js Supabase Kit

One of the reasons why you're hitting a 403 error in your Server Actions is omitting a CSRF token. Let's see how to fix it

If you're encountering a 403 error on Server Actions and API Routes, it is possible that your requests lack a CSRF Token.

By default, the Makerkit middleware at src/middleware.ts will automatically try to validate a CSRF token for HTTP methods such as POST, PUT and DELETE: failing to send a valid CSRF token will result in these requests being forbidden.

To fix this error, check out these pages:

Server Actions: Add a CSRF token to your Server Actions
API Routes: Add a CSRF token to your API Routes

The CSRF Token is sent, but it's not defined

If the CSRF Token is being sent but it's null/undefined, it's likely a bug. In that case, please open a support ticket in our Discord channel.