I’m getting a CORS error when trying to fetch a JSON file from Vercel Blob Storage. I’m fetching from a Framer site using their Fetch functionality . The console error message says: Request header field content-type is not allowed by Access-Control-Allow-Headers in preflight response. The browser b…

@benfwalla A fix has now been released, you can check on this Framer preview that downloading a blob with their Fetch feature works: https://smart-needs-267772.framer.app/ Thanks a lot again!

Hey @benfwalla could you give us the code you’re using to make the fetch requests? Or even better a preview url to your framer site where we can see the issue? Thanks! PS: I just tried to fetch in my chrome console and it worked nicely so I am curious what’s going wrong here.

Yeah, it works for me in Chrome as well, which is making me think the issue lies in Framer. Maybe it’s better to go over to their forum. Here’s a could screenshots of the Network tab in Framer when I try the fetch. Looks like it makes two requests. The first request (the preflight) appears to retu…

Here’s the link to my Framer site! Still in testing. You’ll find the fetch issue happening in the text box that currently reads “Error”: https://firstmover.framer.website/

Hey @vvoyer , I think I was able to isolate the problem a bit more. To recap, when I tried fetching my Vercel blob on Framer, it returned a CORS error. I just tried fetching this json endpoint from jsonplaceholder.com on Framer, and it worked perfectly. The difference was that the jsonplaceholder…

@benfwalla We recently shipped this community post on CORS, might be helpful for your usecase? [image] Different ways to handle CORS on Vercel Discussions Cross-Origin Resource Sharing ( CORS ) issues are common when you are hosting your backend and fronten…

Do you think these lack of headers from Vercel could be the reason for the CORS error? Thanks! It could definitely be the reason! I also see you fixed your production issue by proxying to the blob instead perhaps?

Hey @benfwalla we dug deep and finally found the exact issue (thanks to your debugging), Framer does a fetch request with content-type: json, which triggers a CORS request and expects Access-Control-Allow-Headers to have “content-type” (just like jsonplaceholder.com ). We’re updating our service to …

@vvoyer legend, thank you!! So, I eventually ended up building my own API endpoint with all the required headers and OPTIONS requirements, but I’m glad that you found a native blob solution here. :pray: Having visibility in the Dashboard to see all the Headers that Vercel would send would be helpfu…

CORS Issues with Vercel Blob

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pawlean (Pauline P. Narvas) January 31, 2025, 3:30pm 6

@benfwalla We recently shipped this community post on CORS, might be helpful for your usecase?

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CORS Issues with Vercel Blob

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