---
title: JWT
description: Authenticate users with JWT tokens in services that can't use the session
---

The JWT plugin provides endpoints to retrieve a JWT token and a JWKS endpoint to verify the token.

<Callout type="info">
  This plugin is not meant as a replacement for the session. 
  It's meant to be used for services that can't use the session.
</Callout>

## Installation

<Steps>
<Step>
### Add the plugin to your **auth** config
```ts title="auth.ts"
import { betterAuth } from "better-auth"
import { jwt, bearer } from "better-auth/plugins"

export const auth = betterAuth({
    plugins: [ // [!code highlight]
        jwt(), // [!code highlight]
    ] // [!code highlight]
})
```
</Step>

<Step>
    ### Migrate the database

    Run the migration or generate the schema to add the necessary fields and tables to the database.

    <Tabs items={["migrate", "generate"]}>
        <Tab value="migrate">
        ```bash
        npx @better-auth/cli migrate
        ```
        </Tab>
        <Tab value="generate">
        ```bash
        npx @better-auth/cli generate
        ```
        </Tab>
    </Tabs>
    See the [Schema](#schema) section to add the fields manually.
</Step>
</Steps>    


## Usage

Once you've installed the plugin, you can start using the JWT & JWKS plugin to get the token and the JWKS through their respective endpoints.

## JWT

### Retrieve the token

To get the token, call the `/token`, this will return the following:
  
```json
  { 
    "token": "ey..."
  }
```

Make sure to include the token in the Authorization header of your requests.

```ts
await fetch("/api/auth/token", {
  headers: {
    "Authorization": `Bearer ${token}`
  },
})
```

### Verifying the token
The token can be verified in your own service, without the need for an additional verify call or database check.
For this JWKS is used, the public key can be fetched from the `/api/auth/jwks` endpoint.

Since this key is not subject to a frequent change, it can be cached indefinitely.
The Key ID (kid) that was used to sign a JWT is included in the header of the token.
In the case a JWT with a different kid is received it is recommended to fetch the JWKS again.

```json
  {
    "keys": [
        {
            "crv": "Ed25519",
            "x": "bDHiLTt7u-VIU7rfmcltcFhaHKLVvWFy-_csKZARUEU",
            "kty": "OKP",
            "kid": "c5c7995d-0037-4553-8aee-b5b620b89b23"
        }
    ]
  }
```


## Schema

The JWT plugin adds the following tables to the database:

### JWKS

Table Name: `jwks`

<DatabaseTable
  fields={[
    { 
      name: "id", 
      type: "string", 
      description: "Unique identifier for each web key",
      isPrimaryKey: true
    },
    { 
      name: "publicKey", 
      type: "string", 
      description: "The public part of the web key" 
    },
    { 
      name: "privateKey", 
      type: "string", 
      description: "The private part of the web key" 
    },
    { 
      name: "createdAt", 
      type: "Date", 
      description: "Timestamp of when the web key was created" 
    },
  ]}
  />

## Options

### Algorithm of the Key Pair

The algorithm used for the generation of the keypair. The default is **EdDSA** with the **Ed25519** curve. Below are the available options:

```ts title="auth.ts"
jwt({
  jwks: {
    keyPairConfig: {
      alg: "EdDSA",
      crv: "Ed25519"
    }
  }
})
```

#### EdDSA
- **Default Curve**: `Ed25519`
- **Optional Property**: `crv`
  - Available options: `Ed25519`, `Ed448`
  - Default: `Ed25519`

#### ES256
- No additional properties

#### RSA256
- **Optional Property**: `modulusLength`
  - Expects a number
  - Default: `2048`

#### PS256
- **Optional Property**: `modulusLength`
  - Expects a number
  - Default: `2048`

#### ECDH-ES
- **Optional Property**: `crv`
  - Available options: `P-256`, `P-384`, `P-521`
  - Default: `P-256`

#### ES512
- No additional properties


### Disable private key encryption

By default, the private key is encrypted using AES256 GCM. You can disable this by setting the `disablePrivateKeyEncryption` option to `true`.

For security reasons, it's recommended to keep the private key encrypted.

```ts title="auth.ts"
jwt({
  jwks: {
    disablePrivateKeyEncryption: true
  }
})
```

### Modify JWT payload

By default the entire user object is added to the JWT payload. You can modify the payload by providing a function to the `definePayload` option.

```ts title="auth.ts"
jwt({
  jwt: {
    definePayload: (user) => {
      return {
        id: user.id,
        email: user.email,
        role: user.role
      }
    }
  }
})
```

### Modify Issuer, Audience or Expiration time
If none is given, the BASE_URL is used as the issuer and the audience is set to the BASE_URL. The expiration time is set to 15 minutes.

```ts title="auth.ts"
jwt({
  jwt: {
    issuer: "https://example.com",
    audience: "https://example.com",
    expirationTime: "1h"
  }
})
```
