N
Nuxt•2w ago
Leander

useFetch will return "401 Unauthorized" on inital load

Hi, I am currently developing a frontend application using nuxt. The backend is made using ASP.NET and currently running in a docker container. When I login to my account in the backend, the login is saved in a cookie and this works fine. However when i use useFetch, I get 401 Unauthorized at first but when i go back and forth between the pages without reloading, I get the result I want. Just not on the initial load. The error goes away when I set server to false but I still only get the proper response when going back and forth between the pages.
3 Replies
kapa.ai
kapa.ai•2w ago
Hi @Leander. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave: ---------------------- This issue you're experiencing with useFetch returning a "401 Unauthorized" error on initial load, but working correctly when navigating between pages, is a common problem in Nuxt applications. It's related to how cookies are handled during server-side rendering (SSR) and client-side navigation. Let's break down the problem and potential solutions based on the provided knowledge sources. The root cause of this issue is likely that during the initial server-side render, the cookies (including your authentication cookie) are not being properly passed to the API request made by useFetch. However, once on the client-side, the cookies are available and sent with subsequent requests. Here are a few approaches to solve this issue: 1. Use useRequestHeaders to pass cookies: As mentioned in the Nuxt documentation on passing headers and cookies, you can use useRequestHeaders to proxy cookies to the API call. Here's an example: 
   const headers = useRequestHeaders(['cookie'])
   
   const { data } = await useFetch('/api/your-endpoint', { 
     headers: headers.value
   })
   
   const headers = useRequestHeaders(['cookie'])
   
   const { data } = await useFetch('/api/your-endpoint', { 
     headers: headers.value
   })
This approach ensures that the cookie header is passed along with the request, both on the server and client side. 2. Use a custom fetch wrapper: You can create a custom fetch wrapper that automatically includes the necessary headers. The Stack Overflow answer provides an example of using useAsyncData with $fetch: 
   if (authToken.value) {
     await useAsyncData(async () => {
       try {
         const response = await $fetch(
           // ... your fetch options here
         )
       } catch {
         // ... error handling
       }
     });
   }
   
   if (authToken.value) {
     await useAsyncData(async () => {
       try {
         const response = await $fetch(
           // ... your fetch options here
         )
       } catch {
         // ... error handling
       }
     });
   }
3. Adjust the server option: While you mentioned setting server: false solves the issue but doesn't give the proper response immediately, you might want to consider using lazy: true instead. This is mentioned in the Nuxt documentation on lazy fetching: 
   const { data: posts } = useLazyFetch('/api/posts')
   
   const { data: posts } = useLazyFetch('/api/posts')
This approach will start the fetch on the client-side after hydration, which might solve your issue while still allowing for server-side rendering of the rest of your page. 4. Use a custom useFetch wrapper: As shown in the Stack Overflow answer about custom fetch, you can create a custom useFetch wrapper that handles token refresh and retries: 
   export function useCustomFetch<T>(url: string, options: UseFetchOptions<T> = {}) {
     // ... implementation details
     return useFetch(url, params)
   }
   
   export function useCustomFetch<T>(url: string, options: UseFetchOptions<T> = {}) {
     // ... implementation details
     return useFetch(url, params)
   }
This approach allows you to handle authentication errors and token refreshing in a centralized manner. 5. Check your auth middleware: Ensure that your auth middleware is not interfering with the initial request. As mentioned in the Stack Overflow post about middleware, you might need to adjust your middleware to skip certain checks on the server-side or during initial hydration. Remember to be cautious when passing headers, as noted in the Nuxt documentation:
Be very careful before proxying headers to an external API and just include headers that you need. Not all headers are safe to be bypassed and might introduce unwanted behavior.
In conclusion, the most straightforward solution would be to use useRequestHeaders to pass the cookie header to your useFetch calls. If that doesn't solve the issue, you might need to implement a custom fetch wrapper or adjust your authentication strategy to handle both server-side and client-side scenarios properly. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------
kapa.ai
kapa.ai•2w ago
<@382225756526346240> Kapa.ai is still learning and improving, please let me know how I did by reacting below.
Leander
LeanderOP•2w ago
the first one solved the issue thanks 👍

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