# JSON Web Token (/docs/authentication/jwt)

To enable JWT authentication, you can use the `jwtAuthMiddleware` middleware on your app.

```typescript title="src/middleware.ts"
import { jwtAuthMiddleware, type Middleware } from "xmcp";

const middleware: Middleware = [
  jwtAuthMiddleware({
    secret: process.env.JWT_SECRET!,
    algorithms: ["HS256"],
  }),
  // ... other middlewares
];

export default middleware;
```

You can customize the middleware using the configuration object containing the JWT secret and verify options.

```typescript
const middleware = jwtAuthMiddleware({
  secret: process.env.JWT_SECRET!,
  algorithms: ["HS256"],
  issuer: "https://example.com",
  audience: "https://example.com",
  subject: "user-id",
  expiresIn: "1h",
  notBefore: "1h",
  clockTolerance: 30,
});
```

Check out the [jsonwebtoken](https://www.npmjs.com/package/jsonwebtoken) library for more details on the configuration options.