Ethereum: Safe-Global/Auth Kit CORS Policy Issues on localhost

As an Ethereum developer, you’re likely familiar with the importance of cross-origin resource sharing (CORS) policies in modern web applications. However, Safe-Global/Auth Kit, a popular library for authenticating users on Ethereum, has been known to introduce CORS issues on localhost due to its use of CORS-enabled libraries like CORS.js.

The Issue:

When using Safe-Global/Auth Kit on localhost, you may encounter CORS policy issues that prevent your application from accessing the Ethereum blockchain. This is because Safe-Global/Auth Kit relies on CORS-enabled libraries like CORS.js to detect and handle cross-origin requests.

Workaround Options:

To resolve this issue, we’ll explore two potential workarounds:

  • Disable CORS for Safe-Global/Auth Kit: One solution is to disable the CORS policy for Safe-Global/Auth Kit on localhost by setting the mode option in your configuration file.

  • Use a different authentication library: Another workaround is to switch to a different authentication library that doesn’t rely on CORS-enabled libraries like CORS.js.

Option 1: Disable CORS for Safe-Global/Auth Kit

Ethereum: safe-global/auth-kit CORS policy issues on localhost

You can disable the CORS policy for Safe-Global/Auth Kit by setting the mode option in your configuration file:

import { SafeGlobal } from 'safe-global';




const safeGlobal = new SafeGlobal({


  mode: 'disable',


});




safeGlobal.authenticate({


  // Your authentication credentials...


});

By setting mode to 'disable', you’ll disable CORS for Safe-Global/Auth Kit on localhost. However, keep in mind that this may break some of your application’s functionality.

Option 2: Use a different authentication library

If you’re not ready to disable CORS for Safe-Global/Auth Kit, you can explore alternative authentication libraries that don’t rely on CORS-enabled libraries like CORS.js. One option is to use the ethers.js library, which provides an authentication API that doesn’t require CORS.

Here’s an example of how you can integrate ethers.js with Safe-Global/Auth Kit:

import { SafeAuthPack } from 'safe-auth-pack';


import { SafeGlobal } from 'safe-global';




const safeAuthPack = new SafeAuthPack({


  // Your authentication credentials...


});




const safeGlobal = new SafeGlobal();




safeAuthPack.authenticate(safeGlobal);

By using ethers.js with Safe-Global/Auth Kit, you can avoid CORS policy issues on localhost.

Conclusion:

While disabling the CORS policy for Safe-Global/Auth Kit may seem like a viable workaround, it’s essential to weigh the potential benefits against the drawbacks. By exploring alternative authentication libraries or adjusting your configuration settings, you can ensure a smooth user experience on localhost without relying on CORS-enabled libraries.

Tips and Recommendations:

  • When switching to a different authentication library, make sure to update any dependencies in your project.

  • Consider using ethers.js with Safe-Global/Auth Kit for more reliable and cross-origin-aware authentication.

  • Keep in mind that some features or functionality might be affected by the CORS policy changes.

By implementing these workarounds or alternatives, you can ensure a seamless user experience on localhost while maintaining optimal performance.