---
title: "Reference: MastraAuthAuth0 Class | Auth"
description: "API reference for the MastraAuthAuth0 class, which authenticates Mastra applications using Auth0 authentication."
packages:
  - "@mastra/auth-auth0"
  - "@mastra/core"
---

# MastraAuthAuth0 Class

The `MastraAuthAuth0` class provides authentication for Mastra using Auth0. It verifies incoming requests using Auth0-issued JWT tokens and integrates with the Mastra server using the `auth` option.

## Usage example

```typescript title="src/mastra/index.ts"
import { Mastra } from "@mastra/core";
import { MastraAuthAuth0 } from "@mastra/auth-auth0";

export const mastra = new Mastra({
  server: {
    auth: new MastraAuthAuth0({
      domain: process.env.AUTH0_DOMAIN,
      audience: process.env.AUTH0_AUDIENCE,
    }),
  },
});
```

> **Note:** You can omit the constructor parameters if you have the appropriately named environment variables (`AUTH0_DOMAIN` and `AUTH0_AUDIENCE`) set. In that case, simply use `new MastraAuthAuth0()` without any arguments.

## Constructor parameters

<PropertiesTable
  content={[
    {
      name: "domain",
      type: "string",
      description:
        "Your Auth0 domain (e.g., your-tenant.auth0.com). This is used to verify JWT tokens issued by your Auth0 tenant.",
      isOptional: true,
      defaultValue: "process.env.AUTH0_DOMAIN",
    },
    {
      name: "audience",
      type: "string",
      description:
        "Your Auth0 API identifier/audience. This ensures tokens are intended for your specific API.",
      isOptional: true,
      defaultValue: "process.env.AUTH0_AUDIENCE",
    },
    {
      name: "name",
      type: "string",
      description: "Custom name for the auth provider instance.",
      isOptional: true,
      defaultValue: '"auth0"',
    },
    {
      name: "authorizeUser",
      type: "(user: Auth0User) => Promise<boolean> | boolean",
      description:
        "Custom authorization function to determine if a user should be granted access. Called after token verification. By default, allows all authenticated users with valid tokens.",
      isOptional: true,
    },
  ]}
/>

## Environment Variables

The following environment variables are automatically used when constructor options are not provided:

<PropertiesTable
  content={[
    {
      name: "AUTH0_DOMAIN",
      type: "string",
      description:
        "Your Auth0 domain. Can be found in your Auth0 Dashboard under Applications > Settings.",
      isOptional: true,
    },
    {
      name: "AUTH0_AUDIENCE",
      type: "string",
      description:
        "Your Auth0 API identifier. This is the identifier you set when creating an API in your Auth0 Dashboard.",
      isOptional: true,
    },
  ]}
/>

## Default Authorization Behavior

By default, `MastraAuthAuth0` validates Auth0 JWT tokens and allows access to all authenticated users:

1. **Token Verification**: The JWT token is verified using Auth0's public keys (JWKS)
2. **Signature Validation**: Ensures the token was signed by your Auth0 tenant
3. **Expiration Check**: Verifies the token has not expired
4. **Audience Validation**: Confirms the token was issued for your specific API (audience)
5. **Issuer Validation**: Ensures the token was issued by your Auth0 domain

If all validations pass, the user is considered authorized. To implement custom authorization logic (e.g., role-based access control), provide a custom `authorizeUser` function.

## Auth0 User Type

The `Auth0User` type used in the `authorizeUser` function corresponds to the decoded JWT token payload, which typically includes:

- `sub`: The user's unique identifier (subject)
- `email`: The user's email address (if included in token)
- `email_verified`: Whether the email is verified
- `name`: The user's display name (if available)
- `picture`: URL to the user's profile picture (if available)
- `iss`: Token issuer (your Auth0 domain)
- `aud`: Token audience (your API identifier)
- `iat`: Token issued at timestamp
- `exp`: Token expiration timestamp
- `scope`: Granted scopes for the token
- Custom claims and app metadata configured in your Auth0 tenant

The exact properties available depend on your Auth0 configuration, scopes requested, and any custom claims you've configured.

## Related

[MastraAuthAuth0 Class](/docs/v1/server/auth/auth0)
