google-flights-mcp

MCP server for Google Flights search via SerpApi. Optimized for Business/First class, Star Alliance, multi-city itineraries with EUR pricing.

Features

search_flights — One-way or round-trip search
search_multi_city — Multi-leg itineraries (2-5 legs)
get_booking_options — Direct airline booking links
get_usage — Monthly API usage tracker

Defaults

All defaults are configurable via environment variables in your MCP config:

Env var	Default	Description
`SERPAPI_KEY`	(required)	Your SerpApi API key
`DEFAULT_TRAVEL_CLASS`	`3`	1=Economy, 2=Premium Economy, 3=Business, 4=First
`DEFAULT_AIRLINES`	`STAR_ALLIANCE`	Airline/alliance filter
`DEFAULT_CURRENCY`	`EUR`	Price currency
`DEFAULT_GL`	`at`	Google locale (affects pricing region)
`DEFAULT_HL`	`en`	Language
`DEFAULT_ADULTS`	`1`	Number of passengers
`DEFAULT_HUBS`	`FRA,ZRH,BRU`	Preferred connection airports
`DEFAULT_HOME_AIRPORTS`	`MBA,FRA,ZRH,BRU`	Home airports
`MAX_RESULTS`	`8`	Max flight results per search
`MONTHLY_LIMIT`	`100`	Monthly search budget
`CACHE_TTL_MS`	`3600000`	Cache duration in ms (1hr)
`CACHE_DIR`	`.cache`	Cache directory path

Example with custom settings:

{
  "mcpServers": {
    "google-flights": {
      "command": "node",
      "args": ["/path/to/google-flights-mcp/dist/index.js"],
      "env": {
        "SERPAPI_KEY": "your-key",
        "DEFAULT_TRAVEL_CLASS": "1",
        "DEFAULT_AIRLINES": "",
        "DEFAULT_CURRENCY": "USD",
        "DEFAULT_GL": "us"
      }
    }
  }
}

Setup

1. Get a SerpApi key

2. Build

npm install
npm run build

3. Configure Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or equivalent:

{
  "mcpServers": {
    "google-flights": {
      "command": "node",
      "args": ["/absolute/path/to/google-flights-mcp/dist/index.js"],
      "env": {
        "SERPAPI_KEY": "your-key-here"
      }
    }
  }
}

4. Configure Claude Code

Add to ~/.claude/mcp.json:

{
  "mcpServers": {
    "google-flights": {
      "command": "node",
      "args": ["/absolute/path/to/google-flights-mcp/dist/index.js"],
      "env": {
        "SERPAPI_KEY": "your-key-here"
      }
    }
  }
}

Usage Examples

Simple round-trip

"Find Business class flights from VIE to NRT, departing March 15 returning March 25"

Multi-city

"Search multi-city: VIE→NRT March 15, NRT→BKK March 20, BKK→VIE March 25"

Booking

"Get booking options for this flight" (uses booking_token from search results)

Caching

Responses are cached locally for 1 hour (matching SerpApi's server-side cache). Cached searches don't count against the 100/month limit. Cache files stored in .cache/ directory.

API Budget

Every tool response includes a usage footer showing current consumption:

📊 API Usage: 43/100 searches used (57 remaining) · Resets March 1, 2026

Multi-city searches cost 1 API call per leg (a 3-leg trip = 3 searches).

Development

npm run dev          # Watch mode
npm run build        # Build once
npm start            # Run server

Testing

One real API call per endpoint to capture fixtures, then mock everything:

# Capture fixtures (one-time, needs SERPAPI_KEY)
SERPAPI_KEY=xxx npx ts-node test/capture-fixtures.ts

# Run tests (no API key needed)
npm test