How can I get session/user from api request?

[teddybee]

I write routers and handlers in my app. Other session libraries provide extension for request object. How can I get the fastify server instance from handlers without storing it in a global constant? I assume the [this] is the running FastifyInstance which is not valid with TS 5.1.3. in a handler.

const { user } = await this.getSession(req)

How can I get the user ID or sub from the session?

Next-auth callbacks are working with your plugin? I have the solution to put user id in the next-auth session with a callback, just don`t see it on the getSession() decorator.

[wobsoriano]

My example in README is incorrect and had updated it.

You can use an arrow function together with the fastify instance:

fastify.get('/api/user', async (req) => {
  const session = await fastify.getSession(req)
  return session
})

or with an anonymous function (bound to this):

fastify.get('/api/user', async function (req) {
  const session = await this.getSession(req)
  return session
})

[teddybee]

@wobsoriano I was probably misunderstood, I need "this" in the handler function. Anyway I figured the first question out:

req.server.getSesssion(req)

is working in fastify 4.x. It would be nicer to put the user object into the request itself, if valid.

The userId questions are still opened, could you help with that?

[wobsoriano]

Use callbacks.

An example would be:

await fastify.register(NextAuthPlugin, {
  providers: [
    GithubProvider({}) as Provider,
  ],
  callbacks: {
    session({ session, token }) {
      return {
        ...session,
        userId: token.sub,
      }
    },
  },
})

This thread might also be helpful.

[teddybee]

Thank you for the help, I found that tread also. The solution is to override the session callback`s return:

callbacks: {
    session: async ({ session, user }): Promise<ExtendedUser> => {
    //...
}

and the type of the next-auth`s session

declare module "@auth/core/types" {
  export interface ExtendedUser extends NextAuthUser {
    id: string;   
  }

  export interface Session extends NextAuthSession {
    user: ExtendedUser;
  }
}