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API reference@auth/coreerrors

errors

AccessDenied

Thrown when the execution of the signIn callback fails or if it returns false.

Extends

AccountNotLinked

Thrown when an Email address is already associated with an account but the user is trying an account that is not linked to it.

For security reasons, Auth.js does not automatically link accounts to existing accounts if the user is not signed in.

Extends

AdapterError

One of the database Adapter methods failed during execution.

💡

If debug: true is set, you can check out [auth][debug] in the logs to learn more about the failed adapter method execution.

Example

[auth][debug]: adapter_getUserByEmail
{ "args": [undefined] }

Extends

AuthError

Base error class for all Auth.js errors. It’s optimized to be printed in the server logs in a nicely formatted way via the logger.error option.

Extends

Extended by

CallbackRouteError

This error occurs when the user cannot finish login. Depending on the provider type, this could have happened for multiple reasons.

💡

Check out [auth][details] in the logs to know which provider failed.

Example

[auth][details]: { "provider": "github" }

For an OAuth provider, possible causes are:

  • The user denied access to the application
  • There was an error parsing the OAuth Profile: Check out the provider’s profile or userinfo.request method to make sure it correctly fetches the user’s profile.
  • The signIn or jwt callback methods threw an uncaught error: Check the callback method implementations.

For an Email provider, possible causes are:

  • The provided email/token combination was invalid/missing: Check if the provider’s sendVerificationRequest method correctly sends the email.
  • The provided email/token combination has expired: Ask the user to log in again.
  • There was an error with the database: Check the database logs.

For a Credentials provider, possible causes are:

  • The authorize method threw an uncaught error: Check the provider’s authorize method.
  • The signIn or jwt callback methods threw an uncaught error: Check the callback method implementations.
💡

Check out [auth][cause] in the error message for more details. It will show the original stack trace.

Extends

CredentialsSignin

Can be thrown from the authorize callback of the Credentials provider. When an error occurs during the authorize callback, two things can happen:

  1. The user is redirected to the signin page, with error=CredentialsSignin&code=credentials in the URL. code is configurable.
  2. If you throw this error in a framework that handles form actions server-side, this error is thrown, instead of redirecting the user, so you’ll need to handle.

Extends

Properties

code

code: string = "credentials";

The error code that is set in the code query parameter of the redirect URL.

⚠ NOTE: This property is going to be included in the URL, so make sure it does not hint at sensitive errors.

The full error is always logged on the server, if you need to debug.

Generally, we don’t recommend hinting specifically if the user had either a wrong username or password specifically, try rather something like “Invalid credentials”.

DuplicateConditionalUI

Thrown when multiple providers have enableConditionalUI set to true. Only one provider can have this option enabled at a time.

Extends

EmailSignInError

Happens when the login by an Email provider could not be started.

Possible causes are:

  • The email sent from the client is invalid, could not be normalized by EmailConfig.normalizeIdentifier
  • The provided email/token combination has expired: Ask the user to log in again.
  • There was an error with the database: Check the database logs.

Extends

ErrorPageLoop

Thrown when Auth.js is misconfigured and accidentally tried to require authentication on a custom error page. To prevent an infinite loop, Auth.js will instead render its default error page.

To fix this, make sure that the error page does not require authentication.

Learn more at Guide: Error pages

Extends

EventError

One of the events methods failed during execution.

Make sure that the events methods are implemented correctly and uncaught errors are handled.

Learn more at events

Extends

ExperimentalFeatureNotEnabled

Thrown when an experimental feature is used but not enabled.

Extends

InvalidCallbackUrl

Thrown when Auth.js is unable to verify a callbackUrl value. The browser either disabled cookies or the callbackUrl is not a valid URL.

Somebody might have tried to manipulate the callback URL that Auth.js uses to redirect the user back to the configured callbackUrl/page. This could be a malicious hacker trying to redirect the user to a phishing site. To prevent this, Auth.js checks if the callback URL is valid and throws this error if it is not.

There is no action required, but it might be an indicator that somebody is trying to attack your application.

Extends

InvalidCheck

Thrown when a PKCE, state or nonce OAuth check could not be performed. This could happen if the OAuth provider is configured incorrectly or if the browser is blocking cookies.

Learn more at checks

Extends

InvalidEndpoints

One of the configured OAuth or OIDC providers is missing the authorization, token or userinfo, or issuer configuration. To perform OAuth or OIDC sign in, at least one of these endpoints is required.

Learn more at OAuth2Config or Guide: OAuth Provider

Extends

InvalidProvider

Thrown when an endpoint was incorrectly called without a provider, or with an unsupported provider.

Extends

JWTSessionError

Logged on the server when Auth.js could not decode or encode a JWT-based (strategy: "jwt") session.

Possible causes are either a misconfigured secret or a malformed JWT or encode/decode methods.

When this error is logged, the session cookie is destroyed.

Learn more at secret, jwt.encode or jwt.decode for more information.

Extends

MissingAdapter

Thrown if Auth.js is misconfigured. This could happen if you configured an Email provider but did not set up a database adapter, or tried using a strategy: "database" session without a database adapter. In both cases, make sure you either remove the configuration or add the missing adapter.

Learn more at Database Adapters, Email provider or Concept: Database session strategy

Extends

MissingAdapterMethods

Thrown similarily to MissingAdapter, but only some required methods were missing.

Make sure you either remove the configuration or add the missing methods to the adapter.

Learn more at Database Adapters

Extends

MissingAuthorize

Thrown when a Credentials provider is missing the authorize configuration. To perform credentials sign in, the authorize method is required.

Learn more at Credentials provider

Extends

MissingCSRF

Error for missing CSRF tokens in client-side actions (signIn, signOut, useSession#update). Thrown when actions lack the double submit cookie, essential for CSRF protection.

CSRF (Cross-Site Request Forgery) is an attack leveraging authenticated user credentials for unauthorized actions.

Double submit cookie pattern, a CSRF defense, requires matching values in a cookie and request parameter. More on this at MDN Web Docs.

Extends

MissingSecret

Auth.js requires a secret or multiple secrets to be set, but none was not found. This is used to encrypt cookies, JWTs and other sensitive data.

If you are using a framework like Next.js, we try to automatically infer the secret from the AUTH_SECRET, AUTH_SECRET_1, etc. environment variables. Alternatively, you can also explicitly set the AuthConfig.secret option.

💡

To generate a random string, you can use the Auth.js CLI: npx auth secret

Extends

MissingWebAuthnAutocomplete

Thrown when a WebAuthn provider has enableConditionalUI set to true but no formField has webauthn in its autocomplete param.

The webauthn autocomplete param is required for conditional UI to work.

Extends

OAuthAccountNotLinked

Thrown when an Email address is already associated with an account but the user is trying an OAuth account that is not linked to it.

For security reasons, Auth.js does not automatically link OAuth accounts to existing accounts if the user is not signed in.

💡

If you trust the OAuth provider to have verified the user’s email address, you can enable automatic account linking by setting allowDangerousEmailAccountLinking: true in the provider configuration.

Extends

OAuthCallbackError

Thrown when an OAuth provider returns an error during the sign in process. This could happen for example if the user denied access to the application or there was a configuration error.

For a full list of possible reasons, check out the specification Authorization Code Grant: Error Response

Extends

OAuthProfileParseError

This error occurs during an OAuth sign in attempt when the provider’s response could not be parsed. This could for example happen if the provider’s API changed, or the OAuth2Config.profile method is not implemented correctly.

Extends

OAuthSignInError

Happens when login by OAuth could not be started.

Possible causes are:

  • The Authorization Server is not compliant with the OAuth 2.0 or the OIDC specification. Check the details in the error message.
💡

Check out [auth][details] in the logs to know which provider failed.

Example

[auth][details]: { "provider": "github" }

Extends

SessionTokenError

Logged on the server when Auth.js could not retrieve a session from the database (strategy: "database").

The database adapter might be misconfigured or the database is not reachable.

Learn more at Concept: Database session strategy

Extends

SignInError

Thrown when the user’s sign-in attempt failed.

Extends

Extended by

SignOutError

Represents an error that occurs during the sign-out process. This error is logged when there are issues in terminating a user’s session, either by failing to delete the session from the database (in database session strategies) or encountering issues during other parts of the sign-out process, such as emitting sign-out events or clearing session cookies.

The session cookie(s) are emptied even if this error is logged.

Extends

UnknownAction

Auth.js was requested to handle an operation that it does not support.

See AuthAction for the supported actions.

Extends

UnsupportedStrategy

Thrown when a Credentials provider is present but the JWT strategy (strategy: "jwt") is not enabled.

Learn more at strategy or Credentials provider

Extends

UntrustedHost

Thrown when the trustHost option was not set to true.

Auth.js requires the trustHost option to be set to true since it’s relying on the request headers’ host value.

Official Auth.js libraries might attempt to automatically set the trustHost option to true if the request is coming from a trusted host on a trusted platform.

Learn more at trustHost or Guide: Deployment

Extends

Verification

The user’s email/token combination was invalid. This could be because the email/token combination was not found in the database, or because the token has expired. Ask the user to log in again.

Extends

WebAuthnVerificationError

Thrown when a WebAuthn provider fails to verify a client response.

Extends

WarningCode

type WarningCode = 
  | "debug-enabled"
  | "csrf-disabled"
  | "env-url-basepath-redundant"
  | "env-url-basepath-mismatch"
  | "experimental-webauthn";
  • debug-enabled: The debug option was evaluated to true. It adds extra logs in the terminal which is useful in development, but since it can print sensitive information about users, make sure to set this to false in production. In Node.js environments, you can for example set debug: process.env.NODE_ENV !== "production". Consult with your runtime/framework on how to set this value correctly.
  • csrf-disabled: You were trying to get a CSRF response from Auth.js (eg.: by calling a /csrf endpoint), but in this setup, CSRF protection via Auth.js was turned off. This is likely if you are not directly using @auth/core but a framework library (like @auth/sveltekit) that already has CSRF protection built-in. You likely won’t need the CSRF response.
  • env-url-basepath-redundant: AUTH_URL (or NEXTAUTH_URL) and authConfig.basePath are both declared. This is a configuration mistake - you should either remove the authConfig.basePath configuration, or remove the pathname of AUTH_URL (or NEXTAUTH_URL). Only one of them is needed.
  • env-url-basepath-mismatch: AUTH_URL (or NEXTAUTH_URL) and authConfig.basePath are both declared, but they don’t match. This is a configuration mistake. @auth/core will use basePath to construct the full URL to the corresponding action (/signin, /signout, etc.) in this case.
  • experimental-webauthn: Experimental WebAuthn feature is enabled.
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Auth.js © Balázs Orbán and Team - 2025