Function getServerSession

packages/next-auth/src/next/index.ts:177–230

(...args: GetServerSessionParams<O>)

  | []

export async function getServerSession<
  O extends GetServerSessionOptions,
  R = O["callbacks"] extends { session: (...args: any[]) => infer U }
    ? U
    : Session
>(...args: GetServerSessionParams<O>): Promise<R | null> {
  const isRSC = args.length === 0 || args.length === 1

  let req, res, options: AuthOptions
  if (isRSC) {
    options = Object.assign({}, args[0], { providers: [] })

    // eslint-disable-next-line @typescript-eslint/no-var-requires
    const { headers, cookies } = require("next/headers")
    req = {
      headers: Object.fromEntries((await headers()) as Headers),
      cookies: Object.fromEntries(
        (await cookies()).getAll().map((c) => [c.name, c.value])
      ),
    }
    res = { getHeader() {}, setCookie() {}, setHeader() {} }
  } else {
    req = args[0]
    res = args[1]
    options = Object.assign({}, args[2], { providers: [] })
  }

  options.secret ??= process.env.NEXTAUTH_SECRET ?? process.env.AUTH_SECRET

  const session = await AuthHandler<Session | {} | string>({
    options,
    req: {
      action: "session",
      method: "GET",
      cookies: req.cookies,
      headers: req.headers,
    },
  })

  const { body, cookies, status = 200 } = session

  cookies?.forEach((cookie) => setCookie(res, cookie))

  if (body && typeof body !== "string" && Object.keys(body).length) {
    if (status === 200) {
      // @ts-expect-error
      if (isRSC) delete body.expires
      return body as R
    }
    throw new Error((body as any).message)
  }

  return null
}

let deprecatedWarningShown = false