/api/auth/session returning 404 in getSession

Describe the bug I have been using next-auth without issue for months and it suddenly stopped working today. I haven’t changed any configs.

I am able to log in, but getSession throws an error. I added some logs within the node module and found that the error is a 404 when trying to fetch /api/auth/session. However, that endpoint works without issue when I fetch from the browser.

Here are my logs with the error. I added some console logs to the internal _fetchData2 function in the NextAuth client.

BASEURL http://localhost:3000/api/auth OPTIONS { headers: { cookie: ‘next-auth.csrf-token={csrf-token}; next-auth.callback-url=http%3A%2F%2Flocalhost%3A3000; next-auth.session-token={session-token}’ } } RES Response { size: 0, timeout: 0, [Symbol(Body internals)]: { body: PassThrough { _readableState: [ReadableState], readable: true, _events: [Object: null prototype], _eventsCount: 6, _maxListeners: undefined, _writableState: [WritableState], writable: true, allowHalfOpen: true, _transformState: [Object], [Symbol(kCapture)]: false }, disturbed: false, error: null }, [Symbol(Response internals)]: { url: ‘http://localhost:3000/api/auth/session’, status: 404, statusText: ‘Not Found’, headers: Headers { [Symbol(map)]: [Object: null prototype] }, counter: 0 } } [next-auth][error][client_fetch_error] https://next-auth.js.org/errors#client_fetch_error session FetchError: invalid json response body at http://localhost:3000/api/auth/session reason: Unexpected token < in JSON at position 0 at runMicrotasks (<anonymous>) at processTicksAndRejections (internal/process/task_queues.js:97:5) { message: ‘invalid json response body at http://localhost:3000/api/auth/session reason: Unexpected token < in JSON at position 0’, type: ‘invalid-json’ }

Here is what the response looks like when I fetch from the browser:

{"user":{"name":"{my-name}","email":"{my-email}","image":"{my-profile-image}"},"accessToken":"{access-token}","expires":"2021-05-24T00:26:33.450Z"}

Steps to reproduce

// pages/api/auth/[...nextauth].js
const handler = (req, res) => NextAuth(req, res, {
  debug: true,
  providers: [
    Providers.Google({
      clientId: process.env.GOOGLE_OAUTH_CLIENT_ID,
      clientSecret: process.env.GOOGLE_OAUTH_CLIENT_SECRET
    }),
  ],
  adapter: Adapters.Prisma.Adapter({ prisma }),
  // SQL or MongoDB database (or leave empty)
  database: process.env.DATABASE_URL,
  site: process.env.NEXTAUTH_URL
})

export default handler;

// pages/index.js
export async function getServerSideProps(context) {
  // THIS CAUSES THE ERROR
  const session = await getSession(context);

  if (!session) {
    return {
      redirect: {
        destination: '/api/auth/signin',
        permanent: false,
      },
    }
  }
  console.log('SESSION', session);

  return {
    props: {}
  }
}

Expected behavior I expect to be able to get the session.

Additional context This has been working correctly up until now.

[jeremygottfried]

Nevermind. It worked after restarting my computer, so must have been a stray process.

[sheptang]

I’ve found the solution myself.