MCP server SSE error: Invalid content type, expected "text/event-stream"

How To
1

I created a MCP server using Cursor AI and added a test web front end.

This all works I get data in the browser but when I add it to Cursor>Settings>MCP with some other working MCP servers it errors:

SSE error: Invalid content type, expected “text/event-stream”

The url format is
http://localhost:5555/mcp/sse

Any idea why or how to resolve, Cursor AI tells me everthing is correct

Unfortunately, the documentation doesn’t provide detailed troubleshooting steps for your specific error, but it does validate that your approach and configuration format are correct.

1 Like
2

Any luck with this?

3

No, think its a product issue

4

worked on this again today.
still fails even though if I use a web frontend it connects

5

how to fix this ?
“weather_server”: {
“url”: “http://127.0.0.1:6274/sse”
}