Claude Desktop ui.domain mismatch: hash computed with pathname instead of origin

[kkkpeckkk]

Bug

When using a Skybridge MCP server with Claude Desktop, the widget fails to load with a ui.domain mismatch error.

Claude computes the expected domain hash from the connector URL (e.g. https://my-app.alpic.live), but Skybridge computes it from the URL with
the pathname appended (e.g. https://my-app.alpic.live/mcp), resulting in different hashes.

Root cause

In dist/server/server.js around line 252:

const pathname = extra?.requestInfo?.url?.pathname ?? "";
const url = `${serverUrl}${pathname}`;
                                                                                                                                                   
pathname resolves to /mcp, so the hash is computed on https://my-app.alpic.live/mcp instead of https://my-app.alpic.live.                          
                                                                                                                                                   
Expected fix                                                                                                                                       
                
const url = serverUrl;

Error message                                                                                                                                      

ui.domain mismatch: expected "2cb1365d...claudemcpcontent.com" for connector                                                                       
"https://my-app.alpic.live", but got "7a38f52b...claudemcpcontent.com"                                                                             

Steps to reproduce                                                                                                                                 
                
1. Deploy a Skybridge MCP server on Alpic
2. Connect it to Claude Desktop using the Alpic URL
3. Call a widget tool → ui.domain mismatch                                                                                                         
                                                                                                                                                   
Works fine on ChatGPT since it doesn't use this domain check.          

[qchuchu]

Hey @kkkpeckkk !

Thanks for reaching out. Do you still have the issue on Claude when specifically adding your url with /mcp in the end ?

[kkkpeckkk]

Yes. It works fine on claude web app. Does not work from the desktop