---
id: rest-api
title: REST API
---

NextAuth.js exposes a REST API which is used by the NextAuth.js client.

#### `GET` /api/auth/signin

Displays the sign in page.

#### `POST` /api/auth/signin/:provider

Starts an OAuth signin flow for the specified provider.

The POST submission requires CSRF token from `/api/auth/csrf`.

#### `GET` /api/auth/callback/:provider

Handles returning requests from OAuth services during sign in.

For OAuth 2.0 providers that support the `state` option, the value of the `state` parameter is checked against the one that was generated when the sign in flow was started - this uses a hash of the CSRF token which MUST match for both the POST and `GET` calls during sign in.

#### `GET` /api/auth/signout

Displays the sign out page.

#### `POST` /api/auth/signout

Handles signing out - this is a `POST` submission to prevent malicious links from triggering signing a user out without their consent.

The `POST` submission requires CSRF token from `/api/auth/csrf`.

#### `GET` /api/auth/session

Returns client-safe session object - or an empty object if there is no session.

The contents of the session object that is returned are configurable with the session callback.

#### `GET` /api/auth/csrf

Returns object containing CSRF token. In NextAuth.js, CSRF protection is present on all authentication routes. It uses the "double submit cookie method", which uses a signed HttpOnly, host-only cookie.

The CSRF token returned by this endpoint must be passed as form variable named `csrfToken` in all `POST` submissions to any API endpoint.

#### `GET` /api/auth/providers

Returns a list of configured OAuth services and details (e.g. sign in and callback URLs) for each service.

It can be used to dynamically generate custom sign up pages and to check what callback URLs are configured for each OAuth provider that is configured.

---

:::note
The default base path is `/api/auth` but it is configurable by specifying a custom path in `NEXTAUTH_URL`

e.g.

`NEXTAUTH_URL=https://example.com/myapp/api/authentication`

`/api/auth/signin` -> `/myapp/api/authentication/signin`
:::
