Defining `$fetch` within `useFetch()` doesnt pass cookies on SSR

[MickL]

Defining `$fetch` within `useFetch()` doesnt pass cookies on SSR

[manniL]

@danekslama this is probably #27660

[danielroe]

When using a custom fetch, Nuxt does not perform 'internal' fetches or pass on headers automatically - you will need to do this manually if that's the behaviour you want.

[danekslama]

@danielroe we have a similar issue. It seems that cookies are not somehow reactive in the newest version. It was working before the update to 3.12.2.

Tested on 3.11.2 and working correctly.

[MickL]

@danielroe

How can I have a custom fetch but with all the behavior as before? The docs didnt say anything about the downsides of missing functionality when using custom fetch. Is there any example that has custom fetch but with everything as before?

I just want to have an interceptor that redirects if any response is 401 but this seems to be the most complicated thing ever :(

[Aareksio]

@MickL The docs are not very clear, but you need to recreate the functionality you need:
https://nuxt.com/docs/getting-started/data-fetching#passing-headers-and-cookies

In practice, for cookies, you need something akin to:

export const myFetch = $fetch.create({
  async onRequest(ctx) {
    if (import.meta.server) {
      // Forward cookies to the target
      ctx.options.headers = useRequestHeaders(['cookie'])

      // Save event for later, we need it to forward response cookies
      ;(ctx as any).event = useRequestEvent()
    }
  },
  async onResponse(ctx) {
    if (import.meta.server && ctx.response.headers.get('set-cookie')) {
      // Forward response cookies to the client
      const cookieHeader = ctx.response.headers.get('set-cookie')!
      appendResponseHeader((ctx as any).event, 'set-cookie', cookieHeader)
    }
  },
})

---

After investigating your reproduction, it does not forward any cookie on SSR. You must have been setting it via client-side request in your tests:

Reload page 1: Cookie is not set
Navigate to page 2, back to page 1: Cookie is set