ethers.js: CORS stopped working on cdn-cors.ether.io.

This is for the front-end <script> embed. I just checked my site and this is no longer working:

<script type='text/javascript' integrity='sha384-lx/bREQsHxBzGKC8y4tUIt1LZ/FkCnr/zRfrgW7H+1kJsJmMIFUtxi3FuTwDSQOf' crossorigin='anonymous' src='https://cdn-cors.ethers.io/lib/ethers-5.0.26.umd.min.js'></script>

Throwing:

Access to script at 'https://cdn-cors.ethers.io/lib/ethers-5.0.26.umd.min.js' from origin 'https://MYSITE.COM' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Is there something else we should be doing now?

About this issue

Original URL
State: closed
Created 3 years ago
Comments: 16 (8 by maintainers)

Most upvoted comments

I changed from this:

import { ethers } from "https://cdn.ethers.io/lib/ethers-5.5.4.esm.min.js";

to this:

import { ethers } from "https://cdn-cors.ethers.io/lib/ethers-5.5.4.esm.min.js";

And resolved my problem.

+11

NabiKAZ on Mar 17, 2022

I don’t know what went wrong. I was able to verify CORS worked using cURL, but in browsers it was indeed failing. I wonder if the pre-flight started including a new field and the OPTIONS was cached without a field browsers require.

I flushed the edge caches and it seems to be working now, but if this happens again, I may disable caching of OPTIONS requests.

Thanks for letting me know!

ricmoo on May 10, 2021