GRACE Hello MCP

A very simple remote MCP server (Streamable HTTP transport) that advertises a custom icon per the MCP spec (rev 2025-11-25, SEP-973), ready to deploy on Render.

It exposes one tool, say_hello, and serves a custom PNG icon that is advertised in the initialize response's serverInfo.icons.

Project layout

File	Purpose
server.js	The MCP server (Express + @modelcontextprotocol/sdk, Streamable HTTP).
make_icon.py	Generates static/icon.png (stdlib only, no deps). Edit to change the icon.
static/icon.png	The icon that gets advertised + served.
render.yaml	Render blueprint for one-click deploy.

Run locally

npm install
npm start            # serves on http://localhost:3000

• Landing/health page (shows the icon): http://localhost:3000/
• MCP endpoint: http://localhost:3000/mcp
• Icon: http://localhost:3000/icon.png

Quick smoke test:

curl -s -X POST http://localhost:3000/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-11-25","capabilities":{},"clientInfo":{"name":"curl","version":"0"}}}'

You should see serverInfo.icons in the response.

Or use the official MCP Inspector (renders the icon):

npx @modelcontextprotocol/inspector
# then connect to http://localhost:3000/mcp  (Streamable HTTP)

Deploy on Render

1. Push this folder to a GitHub repo.
2. In Render: New ➜ Blueprint, point it at the repo. It reads render.yaml and creates a free Node web service. (Or New ➜ Web Service manually: build npm install, start npm start.)
3. Render injects RENDER_EXTERNAL_URL automatically, so server.js builds the correct absolute https://<your-service>.onrender.com/icon.png icon URL — no manual env vars needed.
4. Your MCP endpoint is https://<your-service>.onrender.com/mcp.

Note: Render's free plan sleeps on idle, so the first request after a while may take ~30s to wake.

Add it to an MCP client

Claude Code (CLI):

claude mcp add --transport http grace-hello https://<your-service>.onrender.com/mcp

Then in a session: /mcp to see it, and ask Claude to "use say_hello to greet Rajith".

Claude Desktop / other GUI clients: add a remote/HTTP MCP server pointing at https://<your-service>.onrender.com/mcp.

About the icon (read this)

This server advertises its icon correctly per the MCP spec: the icons array appears on serverInfo (and on the tool). It must be an https:// or data: URI — we use the hosted https://.../icon.png.

Whether a client shows it is up to that client. Icon rendering is a newer, inconsistently-supported feature:

• ✅ MCP Inspector and other spec-aware clients read and display it.
• ⚠️ Claude Code / Claude Desktop currently still show their default placeholder for arbitrary third-party servers — the branded icons in Claude's marketplace are first-party integrations configured on Anthropic's side. As client icon support matures, this server is already compliant and will "just work" with no changes.

Customize

• Icon: edit colors/shapes in make_icon.py, then npm run make-icon (regenerates static/icon.png). Or just drop your own 512×512 PNG at static/icon.png.
• Tools: add more setRequestHandler cases / tool definitions in server.js.