Webchat Widget Fails to Load After Zendesk Migration - 403 Forbidden on EU1

Just noticed that our Genesys Cloud Webchat widget is completely failing to initialize on the production site following our migration from Zendesk. The old Zendesk widget loaded instantly with a simple script tag, but this new setup feels incredibly fragile. We are using the Genesys Cloud Webchat SDK version 2.4.0 in the EU1 environment. When the page loads, the console immediately throws a 403 Forbidden error when attempting to fetch the session configuration from the /api/v2/interactions/webchat/config endpoint.

In Zendesk, we just pointed to the embed URL and handled authentication via a simple token exchange. Here, we are trying to replicate that flow by setting the orgId and region correctly in the initialization object. The orgId is definitely correct since we pulled it directly from the Admin settings. The region is set to us-east-1 in the code, but wait, we are in EU1, so it should be eu-west-1. I tried switching it, but the 403 persists. It feels like the API key permissions are wrong, but I have granted the webchat:read and webchat:write scopes to the integration user just like the documentation suggested.

The error response body is empty, which is super unhelpful. I expected something more descriptive like a missing permission or an invalid org ID. In Zendesk, if a token was bad, it told me exactly what was wrong. Here, it just blocks everything silently. I have checked the Network tab, and the request headers look standard. Is there a specific CORS setting I need to adjust in the Genesys Admin console that doesn’t exist in Zendesk? Or is this a known issue with the 2.4.0 SDK in the EU region? The migration timeline is tight, and this basic connectivity issue is blocking all user acceptance testing. Any pointers on how to debug this 403 would be amazing.

This happens because the fundamental difference between real-time routing engine calculations and static metadata captured during bulk export processes. The routing_weight value visible in the Genesys Cloud dashboard does not reflect the actual weight used by the predictive dialer at the moment of the call attempt. See API Documentation

If I remember correctly, a 403 on EU1 often stems from missing Cross-Origin Resource Sharing headers in your web server config, not just API keys. Check that your server allows the Genesys Cloud domain explicitly.

add_header Access-Control-Allow-Origin "https://app.eu1.genesys.cloud";

Verify the allowed origins list matches your tenant URL exactly.