Better-Auth Hono / Tanstack-Start

import { createServerFn } from '@tanstack/react-start'
import { getRequest } from '@tanstack/react-start/server'

export const getSessionFn = createServerFn({ method: 'GET' }).handler(
  async () => {
    const request = getRequest()
    const cookieHeader = request.headers.get('Cookie')

    const response = await fetch('http://localhost:3000/api/auth/get-session', {
      headers: { Cookie: cookieHeader || '' },
    })

    return await response.json()
  },
)