To address your requirements, I'll create a POST route that acts as a proxy to download and stream a zip file without exposing the original URL or storing it on the local file system. I'll use Next.js API Routes with the App Router, which is the latest recommended approach 1.

Here's an implementation that should work for your use case:

I understand that you're encountering an error when trying to download the file. Let's revise the code to address this issue.

Let's revise both the API route and the client-side code to better handle and log errors:

These changes will provide more detailed error information, which should help in diagnosing the issue. Here's a summary of the modifications:

1. In the API route, we're now including the error message in the response when an error occurs.

2. In the client-side code, we've added more robust error handling:

   • We check if the response is JSON (which likely indicates an error) even when the status is OK.
   • We parse and throw any error messages returned by the server.
   • We display the error message to the user via an alert.

With these changes, you should get more information about why the download is failing. Some possible reasons could be:

1. CORS issues: Ensure that the server hosting the file allows cross-origin requests.
2. Network problems: Check if the file URL is accessible from the server.
3. File size limits: Ensure the file size doesn't exceed Vercel's limits.
4. URL validity: Make sure the file URL is correct and accessible.

If you're still encountering issues, the additional error logging should provide more context about what's going wrong. You might want to check the server logs as well for any errors that occur during the file fetch process.