unable_to_create_user
The user could not be created during authentication.
What is it?
This error occurs when Better Auth fails to create a new user during the authentication process. It typically happens during OAuth or SSO-based signup flows when a new user record is expected to be created but the operation fails.
Common Causes
- Database write failure due to connection issues, timeouts, or transaction errors.
- Missing or invalid required fields in the user schema.
- Unique constraint violations (e.g., email already exists).
- Mismatch between your database schema and the expected Better Auth schema.
- Errors thrown inside custom database hooks (e.g.,
user.create). - Misconfigured adapters or database clients.
How to resolve
Verify database connectivity
- Ensure your database is reachable and properly configured.
- Check for connection pool issues, timeouts, or failed queries.
Validate schema and constraints
- Make sure all required user fields are present and correctly typed.
- Check for unique constraints (e.g., email conflicts).
Run migrations
- Ensure your database schema is up to date with the current Better Auth version.
Review custom hooks
- If you are using
databaseHooks.user.create, ensure it is not throwing errors or returning invalid data.
Inspect logs
- Check server logs for detailed error messages during user creation.