mcp-sse

# MCP SSE demo reproducible demo that shows an MCP SSE server fails using the bun runtime but succeeds using nodejs. # steps 1. install dependencies ```bash # or npm | yarn | pnpm install, same effect bun install ``` 2. run the MCP inspector ```bash npm run inspect ``` 3. open the inspector [http://localhost:5173](http://localhost:5173) 4. select SSE as the transport and enter `http://localhost:3500/sse` as the url 5. open dev tools network tab to inspect traffic 6. in another terminal tab / session run the server using bun ```bash npm run start:bun ``` 7. try to connect to the server using the inspector, observe the network (pending SSE connection), server and inspector logs 8. kill the bun server then run the server using nodejs ```bash npm run start:node ``` 9. try to connect to the server using the inspector, observe the network (successful SSE connection and message posting), server and inspector logs