ElevenAir Customer Service — MCP Server (example)

A small, self-contained Model Context Protocol (MCP) server that gives a conversational AI voice agent a set of airline customer-service tools. It powers a demo in which a caller reaches "ElevenAir", authenticates, and rebooks a canceled flight — ending with a real HTML confirmation e-mail.

This is a demo/example project. Bookings and flights are mock data, and the rebooking is simulated (not persisted). The only real side effect is sending the confirmation e-mail over SMTP.

Features

• Five MCP tools exposed over the streamable-HTTP transport.

• Mock data for 10 bookings and a set of alternative flights (JSON files).

• Real confirmation e-mail rendered from a clean HTML template and sent via your own SMTP server (with a plain-text fallback).

• Readable terminal logs (via rich) so you can follow every tool call live.

• Simulated e-mail mode when no SMTP credentials are configured, so the server runs out of the box.

Related MCP server: Airline Flight Delays MCP Server

Tools

Project layout

server.py            FastMCP server and the five tools
data.py              Loads mock data and provides lookup helpers
logs.py              Rich-based terminal logging helpers
email_template.html  HTML e-mail template (tokenized with {{...}})
bookings.json        Mock bookings
flights.json         Mock alternative flights
smoke_test.py        Manual end-to-end check of all tools
requirements.txt     Pinned dependencies
.env.example         Template for SMTP configuration

Requirements

• Python 3.10+ (developed on 3.14)

• An SMTP account if you want real e-mails (optional; otherwise sends are simulated)

Setup

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Configuration

Copy the example environment file and fill in your SMTP details:

cp .env.example .env

SMTP_HOST=smtp.example.com
SMTP_PORT=587          # 587 (STARTTLS) or 465 (SSL)
SMTP_USER=you@example.com
SMTP_PASSWORD=your-app-password
SMTP_FROM=you@example.com

If SMTP_HOST, SMTP_USER, or SMTP_PASSWORD are empty, the server logs a simulated send instead of contacting a mail server.

To receive the confirmation e-mail during a demo, set the passenger email in bookings.json to an inbox you control.

Run

python server.py

The MCP endpoint is served at http://127.0.0.1:8000/mcp, with a health check at http://127.0.0.1:8000/health.

Expose it publicly

A cloud-hosted MCP client needs a public URL to reach the server. For local development, tunnel with ngrok:

ngrok http 8000

Use the resulting HTTPS URL plus /mcp as the server URL, e.g. https://<subdomain>.ngrok-free.app/mcp.

Connect it to a voice agent

Any MCP client that supports the streamable-HTTP transport can use this server:

1. Server URL: your public URL ending in /mcp.

2. Transport: Streamable HTTP.

3. If you tunnel through ngrok, send the HTTP header ngrok-skip-browser-warning: true to skip ngrok's interstitial page.

4. Drive the flow from the agent's instructions: authenticate first, then look up the booking, offer the next flight, rebook, and send the confirmation.

Smoke test

Exercise all five tools in one shot (this sends a real e-mail if SMTP is set):

python smoke_test.py

Security

• Secrets live only in .env, which is git-ignored and must never be committed.

• The server reads all credentials from environment variables.

• Treat any tunnel URL as sensitive while it is live.

Notes

• The network covers five cities: London (LHR), New York (JFK), San Francisco (SFO), Warsaw (WAW), and Berlin (BER).

• Rebooking is a mock: it confirms and e-mails, but does not change stored data.