---
id: 'auth-error-codes'
title: 'Error Codes'
description: 'Supabase Auth Error Codes'
subtitle: 'Learn about the Auth error codes and how to resolve them'
---

## Auth error codes

Supabase Auth can return various errors when using its API. This guide explains how to handle these errors effectively across different programming languages.

## Error types

Supabase Auth errors are generally categorized into two main types:

- API Errors: Originate from the Supabase Auth API.
- Client Errors: Originate from the client library's state.

Client errors differ by language so do refer to the appropriate section below:

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<TabPanel id="javascript" label="JavaScript">
All errors originating from the `supabase.auth` namespace of the client library will be wrapped by the `AuthError` class.

Error objects are split in a few classes:

- `AuthApiError` -- errors which originate from the Supabase Auth API.
  - Use `isAuthApiError` instead of `instanceof` checks to see if an error you caught is of this type.
- `CustomAuthError` -- errors which generally originate from state in the client library.
  - Use the `name` property on the error to identify the class of error received.

Errors originating from the server API classed as `AuthApiError` always have a `code` property that can be used to identify the error returned by the server. The `status` property is also present, encoding the HTTP status code received in the response.

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<$Show if="sdk:dart">
<TabPanel id="dart" label="Dart">
All errors originating from the `supabase.auth` namespace of the client library will be wrapped by the `AuthException` class.

Error objects are split in a few classes. `AuthApiException` is an exception which originates from the Supabase Auth API.

Errors originating from the server API classed as `AuthApiException` always have a `code` property that can be used to identify the error returned by the server. The `statusCode` property is also present, encoding the HTTP status code received in the response.

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All errors originating from the `supabase.auth` namespace of the client library will be a case of the `AuthError` enum.

The `api(message:errorCode:underlyingData:underlyingResponse:)` case is a special case for errors which originates from the Supabase Auth API, this error always have an `errorCode` property that can be used to identify the error returned by the server.

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<$Show if="sdk:python">
<TabPanel id="python" label="Python">
All errors originating from the `supabase.auth` namespace of the client library will be wrapped by the `AuthError` class.

Error objects are split in a few classes. `AuthApiError` is an error which originate from the Supabase Auth API.

Errors originating from the server API classed as `AuthApiError` always have a `code` property that can be used to identify the error returned by the server. The `status` property is also present, encoding the HTTP status code received in the response.

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All exceptions originating from the `supabase.auth` namespace of the Kotlin client library will be a subclass of `RestException`.

Rest exceptions are split into a few classes:

- `AuthRestException` -- exceptions which originate from the Supabase Auth API and have a `errorCode` property that can be used to identify the error returned by the server.
- `AuthWeakPasswordException` -- an `AuthRestException` which indicates that the password is too weak.
- `AuthSessionMissingException` -- an `AuthRestException` which indicates that the session is missing, if the user was logged out or deleted.

All instances and subclasses of a `AuthRestException` have a `errorCode` property that can be used to identify the error returned by the server.

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## HTTP status codes

Below are the most common HTTP status codes you might encounter, along with their meanings in the context of Supabase Auth:

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### [403 Forbidden](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/403)

Sent out in rare situations where a certain Auth feature is not available for the user, and you as the developer are not checking a precondition whether that API is available for the user.

### [422 Unprocessable Entity](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/422)

Sent out when the API request is accepted, but cannot be processed because the user or Auth server is in a state where it cannot satisfy the request.

### [429 Too Many Requests](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/429)

Sent out when rate-limits are breached for an API. You should handle this status code often, especially in functions that authenticate a user.

### [500 Internal Server Error](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/500)

Indicate that the Auth server's service is degraded. Most often it points to issues in your database setup such as a misbehaving trigger on a schema, function, view or other database object.

### [501 Not Implemented](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/501)

Sent out when a feature is not enabled on the Auth server, and you are trying to use an API which requires it.

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## Auth error codes table

The following table provides a comprehensive list of error codes you may encounter when working with Supabase Auth. Each error code is associated with a specific issue and includes a description to help you understand and resolve the problem efficiently.

<ErrorCodes service="auth" />

## Best practices for error handling

- Always use `error.code` and `error.name` to identify errors, not string matching on error messages.
- Avoid relying solely on HTTP status codes, as they may change unexpectedly.
