AI Sales MCP Server

Exposes ERP data to Cursor / Claude via MCP.

How it works (3 files)

settings.py   →  reads .env (backend URL, API key, user id)
erp_api.py    →  get_erp_data("/sales") calls Express
server.py     →  @mcp.tool functions + mcp.run()

Cursor / Claude  →  server.py (tool)  →  erp_api.py  →  Express  →  Postgres

Start the whole system

MCP talks to the Express backend. Start backend (and DB) first, then MCP.

1. Backend + database

# From repo root — ensure Postgres is running and DATABASE_URL is set
cd backend
cp ../.env.example ../.env   # or use backend/.env
npm install
npx prisma migrate deploy
npx tsx prisma/seed.ts
npm run dev

Backend: http://localhost:4000

2. MCP server deps + env

cd mcp_server
uv sync
cp .env.example .env

Edit .env (see Environment variables below), then use one of the run modes in the sections that follow.

Environment variables

Copy from .env.example:

BACKEND_URL=http://localhost:4000
INTERNAL_API_KEY=dev-internal-key-change-me
MCP_ACTING_USER_ID=
MCP_TRANSPORT=stdio

Variable	Required	Where to get the value
`BACKEND_URL`	Yes	Express server URL. Local default: `http://localhost:4000` (see `backend/README.md`). Use your deployed API URL for remote backends.
`INTERNAL_API_KEY`	Yes	Must match the backend’s `INTERNAL_API_KEY`. Local default in `backend/.env` / root `.env.example`: `dev-internal-key-change-me`. Sent as `X-Internal-Key`.
`MCP_ACTING_USER_ID`	Yes	ERP user id (cuid) used for RBAC. Get it after seeding: login as `admin@acme.com` / `Password123!`, or query Postgres `User` table (`SELECT id, email FROM "User";`). Seed logins are in `backend/README.md`. Sent as `X-Acting-User-Id`.
`MCP_TRANSPORT`	No	Documented default is `stdio` (Cursor / Claude Desktop). For HTTP remote mode use the `fastmcp run --transport http` command below.

Example after seeding (id will differ on your machine):

MCP_ACTING_USER_ID=cmrxavwxt008quumiiag90vui   # e.g. admin@acme.com

Inspect / develop with FastMCP

Inspect tools (CLI summary)

cd mcp_server
uv run fastmcp inspect server.py

JSON report:

uv run fastmcp inspect server.py --format mcp
# or write to a file:
uv run fastmcp inspect server.py --format mcp -o inspect.json

MCP Inspector (interactive UI)

Starts the server with the MCP Inspector for trying tools in the browser:

cd mcp_server
uv run fastmcp dev inspector server.py

Optional ports:

uv run fastmcp dev inspector server.py --ui-port 6274 --server-port 6277

Ensure .env is filled and the Express backend is running before calling tools.

Run stdio locally (manual)

uv run python server.py
# or
uv run fastmcp run server.py --transport stdio

Local setup — Claude Desktop

Install this server into Claude Desktop (writes Claude’s MCP config):

cd mcp_server
uv run fastmcp install claude-desktop server.py \
  --name ai-sales-erp \
  --env-file .env

Or pass env vars explicitly:

uv run fastmcp install claude-desktop server.py \
  --name ai-sales-erp \
  --env BACKEND_URL=http://localhost:4000 \
  --env INTERNAL_API_KEY=dev-internal-key-change-me \
  --env MCP_ACTING_USER_ID=YOUR_USER_ID

Then restart Claude Desktop. Claude launches the MCP process via stdio; keep the Express backend running on BACKEND_URL.

Config file (macOS): ~/Library/Application Support/Claude/claude_desktop_config.json

Local setup — Cursor

Option A — FastMCP install

cd mcp_server
uv run fastmcp install cursor server.py \
  --name ai-sales-erp \
  --env-file .env

Option B — Manual `mcp.json`

{
  "mcpServers": {
    "ai-sales-erp": {
      "command": "/Users/pratik/Work/ai-sales/mcp_server/.venv/bin/python",
      "args": ["server.py"],
      "cwd": "/Users/pratik/Work/ai-sales/mcp_server",
      "env": {
        "BACKEND_URL": "http://localhost:4000",
        "INTERNAL_API_KEY": "dev-internal-key-change-me",
        "MCP_ACTING_USER_ID": "YOUR_USER_ID"
      }
    }
  }
}

Update paths for your machine. Restart Cursor / reload MCP after changes.

Remote setup (HTTP)

Local Claude/Cursor installs use stdio (client spawns server.py). For a remote MCP, run the server as an HTTP process and point clients at its URL.

1. Start MCP over HTTP

cd mcp_server
# Backend must be reachable from this host (set BACKEND_URL in .env)
uv run fastmcp run server.py --transport http --host 0.0.0.0 --port 8000

Default path is /mcp/, so the endpoint is:

http://<host>:8000/mcp/

Use your public hostname / reverse proxy URL in production.

2. Connect Claude Desktop to remote HTTP

Claude Desktop’s config file prefers stdio. Bridge HTTP with mcp-remote:

{
  "mcpServers": {
    "ai-sales-erp": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "http://YOUR_HOST:8000/mcp/"]
    }
  }
}

Or add a custom connector in Claude: Settings → Connectors → Add custom connector → paste https://YOUR_HOST/mcp/ (for internet-reachable servers; OAuth if required).

3. Connect Cursor to remote HTTP

In Cursor MCP settings / mcp.json, use a URL entry (Streamable HTTP):

{
  "mcpServers": {
    "ai-sales-erp": {
      "url": "http://YOUR_HOST:8000/mcp/"
    }
  }
}

If your Cursor build only supports stdio, use the same npx mcp-remote ... bridge as Claude Desktop.

4. Quick check against a remote server

uv run fastmcp list http://YOUR_HOST:8000/mcp/
uv run fastmcp inspect http://YOUR_HOST:8000/mcp/

Tools (all in `server.py`)

Tool	What it does
`search_employees`	Find employees
`list_sales`	List sales with filters
`search_customers`	Find customers
`get_dashboard`	Dashboard metrics
`top_customers`	Top customers by revenue
`top_products`	Top products by revenue

Add a new tool

Open server.py and copy this pattern:

@mcp.tool
async def my_new_tool(name: str) -> str:
    """Short description for the AI."""
    data = await get_erp_data("/some/path", {"search": name})
    return to_json(data)

Restart the MCP client (or reload MCP) so it picks up the new tool.