Response ChatGPT App Guide

Step-by-step setup for ChatGPT Developer Mode.

Response ChatGPT App

Runs the StateSet Response workspace inside ChatGPT — a React widget rendered by ChatGPT Apps, backed by a Node MCP server that exposes the stateset-response-chat tool.

Piece	Role
React widget	The workspace UI, rendered in ChatGPT
MCP server	Exposes stateset-response-chat over SSE
Connector	Registered in ChatGPT Developer Mode

This guide builds the widget, runs the server, and connects it.

ChatGPT reaches the MCP server over SSE, so the endpoint has to be publicly resolvable — a localhost URL won’t work. Step 3 covers exposing it.

1) Build the widget assets

git clone https://github.com/stateset/stateset-response-chatgpt-app.git
cd stateset-response-chatgpt-app
pnpm install
pnpm run build

The build emits stateset-response.html/js/css inside assets/.

2) Run the MCP server

cd server
pnpm install
STATESET_API_BASE_URL=https://api.stateset.com \
STATESET_API_KEY=sk-... \
pnpm start

Without credentials, the server uses sample data for local testing.

3) Expose the MCP server

Use a tunnel to expose the SSE endpoint:

ngrok http 3030

The endpoint becomes <public-url>/mcp.

Confirm the server is actually serving MCP before wiring ChatGPT to it — a connector that fails here gives no useful error:

# Must return an SSE stream, not JSON
curl -sS -N -H 'Accept: text/event-stream' "$MCP_URL/mcp" | head -c 200

An event: line means the server is ready. JSON or a 404 means the MCP route is not mounted — usually the server is running but on a different path or port than the one you exposed.

4) Add the connector in ChatGPT

1. Open ChatGPT → Settings → Developer Mode → Connectors.
2. Click Add connector, choose MCP via SSE.
3. Name it Stateset Response.
4. Paste <public-url>/mcp as the endpoint.
5. Save and confirm the connector is online.

5) Test the app

@Stateset Response open the customer support workspace for org 1234.

Troubleshooting

• Re-run pnpm run build if assets are missing.
• Verify the tunnel is reachable and SSE is stable.
• Confirm API credentials when using live data.

Related Documentation

• App README

Next steps

Deploy the ChatGPT app

Hosting this on managed Kubernetes instead of locally.

MCP servers

The wider set of servers StateSet publishes.

Agent Gate

Requiring a proof before a tool call runs.

ResponseCX platform

The platform the widget talks to.