Flight price APIs for developers: what actually exists
I’m building a flight booking agent to improve the booking experience. This is a growing reference list of what I’ve found so far. Everything here is accessible to individual developers and AI agents. Organised by setup speed. Last verified: July 2026.
What doesn’t exist (or isn’t accessible)
Before the list — save yourself the time.
- Google Flights API — doesn’t exist as a public API. You can get the data via SerpAPI or the google-flights-mcp-server, but there’s no official API.
- Skyscanner API — partner-only, closed to new developers. All open-source scrapers are low-star and mostly broken.
- Kiwi.com Tequila — removed their free tier. $49/month minimum now. (Though the Kiwi MCP server on Smithery still works.)
- Open-source flight pricing data — doesn’t exist. All pricing data lives inside GDS systems (Amadeus, Sabre, Travelport) or behind airline websites.
Quick comparison
Open-source / agent-native (MCP built in):
| Tool | Free tier | Speed | Coverage |
|---|---|---|---|
| LetsFG | Unlimited searches | 60–90s (full), 2–5s (discover) | 400+ airlines incl. LCCs |
| travel-hacking-toolkit | Free (open source) | Varies | Cash + points + miles + awards |
| flights-mcp | Free (open source) | Varies | Multi-source |
| mcp-flight-search | 100 searches/mo | ~5s | Google Flights |
Traditional APIs (MCP via wrapper):
| Tool | Free tier | Speed | Coverage |
|---|---|---|---|
| Amadeus | 500 calls/mo | 2–5s | ~300 airlines (no LCCs) |
| SerpAPI | 100 searches/mo | ~5s | Google Flights |
| Duffel | Test only | 2–5s | 150+ airlines (NDC) |
| Travelpayouts | Free (affiliate) | Cached | 729 airlines |
Open-source and agent-native
LetsFG
Meta-search engine that hits Skyscanner, Kiwi, Kayak, Momondo, and direct airline websites (Ryanair, United, Southwest, EasyJet, Spirit, AirAsia, and hundreds more). Built specifically for AI agents — MCP server included.
- GitHub: LetsFG/LetsFG (1.5k+ stars, MIT)
- Install:
pip install letsfg && letsfg auth(one-time Twitter/X challenge gives you a 90-day Bearer token) - MCP server: letsfg-mcp on npm — drop into Hermes, Claude, or any MCP-compatible agent
- Free tier: Unlimited searches via CLI/SDK or their PFS (Programmatic Flight Search) API
- Paid tier: Developer API with direct airline booking URLs, $0.10–$0.50 per search
- Speed: 60–90s for full search (server-side async), 2–5s for their
/discoverendpoint (indicative prices for 20 destinations in one call) - Agent docs: letsfg.co/for-agents
- What to watch for: Twitter/X is the only free auth path. Search takes 60–90 seconds. Connector reliability varies — scrapers break when airline sites change. The 1% unlock fee (min $3) applies even on cheap flights.
travel-hacking-toolkit
AI-powered travel hacking toolkit with MCP servers. Covers cash, points, miles, and award flight availability across airlines. Drop-in skills for Claude, Codex, and Hermes.
- GitHub: borski/travel-hacking-toolkit (576 stars, MIT)
- Install: Clone the repo and follow the setup instructions — MCP servers are included for each travel domain (flights, hotels, points)
- Best for: Finding award flight availability, comparing cash vs. points pricing, and optimising redemptions. If you’re building a travel agent that needs to reason about loyalty programmes, this is the toolkit.
- What to watch for: Focused on the US travel hacking ecosystem (credit card points, airline miles). Less useful if you’re only looking for cash prices.
flights-mcp
Standalone MCP server for flight search. Python-based, lighter weight than LetsFG.
- GitHub: ravinahp/flights-mcp (209 stars)
- Install: Clone the repo and follow the README — runs as a stdio MCP server
- Best for: Quick integration into any MCP-compatible agent when you don’t need LetsFG’s full meta-search engine
- What to watch for: Less coverage than LetsFG — check the repo’s connector list to see which sources it pulls from.
mcp-flight-search
MCP server that wraps SerpAPI for real-time Google Flights data.
- GitHub: arjunprabhulal/mcp-flight-search (42 stars)
- Install: Clone the repo, set your
SERPAPI_API_KEYenv var, run as MCP server - Requires: SerpAPI key (free tier: 100 searches/month)
- Best for: If you already have a SerpAPI subscription, this gives you Google Flights data in MCP format with zero extra work.
MCP servers ready to use
These are install-and-go. No custom code needed. Install counts are from Smithery.
| Server | Source (installs) | What it does |
|---|---|---|
| Kiwi | Smithery (15k+) | Search flights, compare prices, manage bookings |
| CHEAP_FLIGHTS_MCP | Smithery (1.3k) | RyanAir, WizzAir, Google Flights simultaneously |
| trvl-mcp | npm | Flights, hotels, trains, cars, ferries. No API keys |
| google-flights-mcp-server | npm | Google Flights with date grid pricing |
| Jinko Travel | npm | Flight search, booking, trip management |
| Amadeus MCP | npm | Wraps Amadeus Self-Service APIs |
Install any Smithery server with: npx -y smithery mcp add <server-name>
Traditional APIs with free tiers
Amadeus Self-Service
The biggest GDS in the world. Stable, reliable, structured data. Coverage gap: most low-cost carriers (Ryanair, EasyJet, etc.) don’t participate in GDS systems.
- Site: developers.amadeus.com
- Free tier: 500 calls/month in test environment with real data
- Paid: $0.001–$0.035 per call in production
- Speed: 2–5 seconds
- Python SDK: amadeus on PyPI (MIT, v12)
- Node SDK: amadeus on npm (v11)
- Best for: Reliable structured data, full booking flow (search → price → book → manage PNR)
SerpAPI (Google Flights)
Scraping middleman — you pay them to handle Google Flights’ anti-bot protections. Clean JSON output, no parsing needed.
- Site: serpapi.com
- Free tier: 100 searches/month
- Paid: $50/month for 5,000 searches
- Python SDK: serpapi on PyPI
- Best for: Quick prototyping, Google Flights data without the scraping headache
Duffel
NDC-native flight booking API. 150+ airlines. Pay-per-booking model.
- Site: duffel.com
- Free tier: Test environment only
- JS SDK: @duffel/api on npm (v4.28, actively maintained)
- Python SDK: duffel-api on PyPI (v0.6, last updated 2023)
- Best for: Building a booking product with direct airline integrations. Requires commercial agreement for production.
Travelpayouts
Free affiliate-based model. Cached prices, not real-time.
- Site: travelpayouts.com
- Cost: Free (you earn commissions on bookings)
- 729 airlines, but prices are cached
- MCP server: @theyahia/travelpayouts-mcp on npm (community-maintained)
- Best for: Price alert features, deal monitoring, “find cheap flights” tools where freshness isn’t critical
A note on discovery
When you’re looking for developer tools, search the package registries and GitHub, not just API marketplaces. The most useful options here (LetsFG, flights-mcp, travel-hacking-toolkit, the MCP servers on Smithery) don’t show up in traditional “flight API” roundups — they’re built by the agent community, for the agent community.