Cursor: SSE error: TypeError: terminated: Body Timeout Error

[iduanyingjie]

Describe the bug
Curosr connect to server setting:

{
    "mcpServers": {
        "redshift": {
            "url": "http://localhost:55600/sse"
        }
    }
}

After waiting for a few minutes:

Normal after Refresh:

To Reproduce
Steps to reproduce the behavior:

1. use dependency
   rmcp = { git = "https://github.com/modelcontextprotocol/rust-sdk", branch = "main", features = [ "client", "server","transport-sse","transport-sse-server", "transport-io", "transport-child-process", "tower"] }

2. dev server

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    tracing_subscriber::registry()
        .with(
            tracing_subscriber::EnvFilter::try_from_default_env()
                .unwrap_or_else(|_| "info".to_string().into()),
        )
        .with(tracing_subscriber::fmt::layer())
        .init();
    let ct = SseServer::serve(BIND_ADDRESS.parse()?).await?.with_service(RedshiftMcpRouter::new);

    tokio::signal::ctrl_c().await?;
    ct.cancel();
    Ok(())
}

Logs

[4t145]

I will have a look on this.

[4t145]

It's a bug literally need time to debug.

And I found some issues reporting the same error.

• TypeError: terminated: Body Timeout Error Calling MCP tool GLips/Figma-Context-MCP#41
• MCP SSE Error: Body Timeout Error AltimateAI/vscode-dbt-power-user#1626

So I guess it's a bug of cursor since these mcp server is developed upon typescript sdk but encounter the same error?

[4t145]

Ohhh I found the reason, I need to send ping message in sse stream to make cursor happy.

[easonhuang123]

hi, i have the same problem. more details: GLips/Figma-Context-MCP#68 (comment)

[4t145]

@easonhuang123 SSE server should periodically send ping message (SSE comment) to make cursor happy.