LetsFG MCP工具

Try it right now — no install needed

Human users: Use letsfg.co and search flights instantly in your browser:

Things worth knowing before you build

- A card on file is required for every hotel call, including search. That is unusual and it is deliberate: a hotel search opens a real session at the supplier, and booking blocks a real rate. We would rather refuse up front than let you reach the point of commitment and discover you cannot pay. The same card that authorises flight booking authorises hotels — there is no separate hotel signup. - Only free-cancellation, pay-later rates are sold. Those are the rates where the balance can safely be settled with the supplier after booking, which is what makes 5%-now/rest-later work at all. You will see fewer results than a metasearch shows you. Every one of them can actually be booked. - Booking is asynchronous. book_hotel returns a booking_job_id, not a booking — the real thing takes minutes. Poll hotel_booking(job_id) until status is succeeded or failed, or call book_hotel_and_wait and let the SDK do it. This is not ceremony: it is what makes it impossible to charge a card and then lose the confirmation to a timeout. - The fee is charged before the room is committed. A declined card therefore costs nothing to unwind — no reservation exists and nothing is charged. - Do not retry a booking blindly. Calling book_hotel twice for the same rate books the room twice and charges two reservation fees. - price is what the guest pays. There is no wholesale figure in the response to quote by mistake.

Install

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Reads LETSFG_BEARER_TOKEN env var or ~/.letsfg/config.json (the token from the connect flow)

result = await search_local("GDN", "BCN", "2026-06-15")

for offer in result.offers[:5]: print(f"{offer.airlines[0]}: {offer.currency} {offer.price}") ```

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🖥️ CLI / SDK — same token, ranking runs locally

pip install letsfg
export LETSFG_BEARER_TOKEN=<token from the connect flow>
letsfg search LHR BCN 2026-06-15
letsfg search LHR JFK 2026-06-15 --cabin C   # cabin class: M economy, W premium, C business, F first

The SDKs read the token from LETSFG_BEARER_TOKEN or ~/.letsfg/config.json. letsfg auth performs that connect flow itself: it registers as an OAuth client, opens https://letsfg.co/connect for a person to approve, and writes the token to ~/.letsfg/config.json. Add --no-browser to print the URL instead of opening one.

⚡ Developer API — paid, server-side, direct booking URLs

A separate paid product for high-volume commercial integrations; most agents should not use it. Prepaid credits, results in seconds, direct airline booking URLs — plus /discover (20 destinations in one call, 1 credit), async polling, NL query parsing, and a free sandbox.

```bash

Register, then search with your API key

curl -X POST https://letsfg.co/developers/api/v1/agents/register \ -H "Content-Type: application/json" \ -d '{"agent_name":"my-agent","email":"you@example.com"}'

curl -X POST https://letsfg.co/developers/api/v1/flights/search \ -H "X-API-Key: letsfg_..." \ -H "Content-Type: application/json" \ -d '{"origin":"LHR","destination":"BCN","date_from":"2026-06-15"}'

Pricing: $0.50/search for the first 10 each month, $0.20 for 11–1,000, $0.10 beyond. Minimum top-up $5. Test for free in the sandbox first. Full docs: [letsfg.co/developers/api/docs](https://letsfg.co/developers/api/docs).

<details>
<summary><strong>Full search → book flow (MCP / PFS agent path, no unlock step)</strong></summary>

Over raw HTTP the same four steps are POST /api/search, GET /api/results/<id>, POST /api/agent-book, POST /api/agent-book/status.

letsfg unlock is a Developer API–only command for the paid, prepaid-credit product above — it isn't part of this flow. See CLI Commands.

</details>

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Python SDK

from letsfg import LetsFG

bt = LetsFG()  # reads LETSFG_API_KEY from env
flights = bt.search("LHR", "JFK", "2026-04-15")
print(f"{flights.total_results} offers, cheapest: {flights.cheapest.summary()}")

JavaScript SDK

import { LetsFG } from 'letsfg';

const bt = new LetsFG({ apiKey: 'letsfg_...' });
const flights = await bt.search('LHR', 'JFK', '2026-04-15');
console.log(`${flights.totalResults} offers`);

Python SDK (cloud search)

```python from letsfg.local import search_local

CLI Commands

All commands accept --json for structured output and --api-key to override the env variable.

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CLI / SDK / MCP (free, cloud-backed)

Connect the MCP (once, card added at letsfg.co/connect) → card-backed token → Search (free) → Book (hold → agent → PNR)

1. Auth — add https://letsfg.co/developers/api/mcp as an MCP server and approve it. The OAuth consent step opens letsfg.co/connect, where a card is added in a 0.00 Revolut setup. Nothing is charged. The SDKs read that token from LETSFG_BEARER_TOKEN or ~/.letsfg/config.json.
2. Search — letsfg search LHR BCN 2026-06-15 calls POST https://letsfg.co/api/search, polls until done (8–10 s to first results), and applies the open-source ranking algorithm locally.
3. Book — POST /api/agent-book holds the fare plus markup on the card and starts a LetsFG booking agent; POST /api/agent-book/status reports completed with the PNR (4–11 minutes), or failed with the hold released. Nothing extra is added at booking.

PFS — raw API (same as CLI, without the wrapper)

Card connected at letsfg.co/connect -> Bearer token -> POST /api/search -> poll GET /api/results/<id> -> POST /api/agent-book -> poll POST /api/agent-book/status

1. Get a Bearer token — connect through the MCP OAuth flow; the consent step is letsfg.co/connect (card or Revolut Pay, 0.00, nothing charged). POST /api/agent-access/request answers 402 with add_card_url and the steps. The MPP wallet lane ($0.01 once) verifies at POST /api/agent-access/verify with Authorization: Payment.
2. Search — POST https://letsfg.co/api/search with Authorization: Bearer <token>. Returns { search_id }. Poll GET /api/results/<search_id> immediately, then every 2 s, until status leaves searching. Then keep polling while split_ticket_pending or gf_enrich_pending is true — the split-ticket offer merges in after the status turns terminal.
3. Book — POST /api/agent-book → booking_ref; poll POST /api/agent-book/status until completed (PNR) or failed (hold released, nothing charged).

Developer API — paid, direct booking URLs

Register → Fund balance → Discover or Search (credits) → Direct booking URL (no checkout)

1. Discover — POST /flights/discover with up to 20 destinations, get indicative prices sorted cheapest-first. 1 credit, 2–5 s. Use to rank options before committing to a full search.
2. Full search — POST /flights/search (blocking) or /flights/search/async (non-blocking + poll). 1 credit, 8–10 s to first results.
3. Book — each offer includes a direct airline booking_url. No LetsFG fee, no checkout step.

<details> <summary><strong>Virtual interlining</strong></summary>

The server-side engine builds cross-airline round-trips by combining one-way fares from different carriers. A Ryanair outbound + Wizz Air return can save 30-50% vs booking a round-trip on either airline alone.

</details>

<details> <summary><strong>City-wide airport expansion</strong></summary>

Search a city code and LetsFG automatically searches all airports in that city. LON expands to LHR, LGW, STN, LTN, SEN, LCY. NYC expands to JFK, EWR, LGA. Works for 25+ major cities worldwide.

</details>

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🖥️ Omarchy desktop plugin

Search hundreds of airlines from the Omarchy bar. Type two airport codes and a date, press Search, click an offer to open it. The panel lives in this repo — manifest.json, BarWidget.qml, Panel.qml and Model.js at the root — and runs on the same engine as the CLI and the MCP server, ordered by the same open-source ranking algorithm in sdk/js/src/ranking.ts.

<p align="center"><img src="preview.png" alt="LetsFG Flights panel in the Omarchy bar" width="820"></p>

Install

omarchy plugin add https://github.com/LetsFG/LetsFG.git --enable

Then add LetsFG Flights to a bar section in the Omarchy bar settings. The panel reads your LetsFG token from ~/.letsfg/config.json (what letsfg auth writes) and renews it itself, or connects a card from the panel via letsfg.co/connect — nothing is charged. See OMARCHY-PLUGIN.md.

Remove

omarchy plugin remove io.github.letsfg.flights

That removes the plugin only. Your token is yours — delete ~/.letsfg/config.json yourself if you want it gone.

The plugin bundles no API keys. It authenticates with a token you create and can revoke, it never asks for card details, and it never starts a search on its own — no background poll, no price watch, no refresh timer. Every host it can contact, every file it reads or writes, and the anonymous installation id it sends so we can tell whether anyone is using it, are documented in full in OMARCHY-PLUGIN.md.

Requires the Omarchy Quattro shell. MIT, like the rest of this repo. Not affiliated with, sponsored by, or endorsed by Omarchy or 37signals.

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Real prices: LetsFG vs Google Flights

We searched 5 routes on Google Flights and LetsFG on the same day (2026-08-05), for flights departing 2026-09-16. Same airline, same number of stops — LetsFG was cheaper every time:

$133 cheaper across 5 routes in a verified comparison (2026-08-05). Google Flights inflates on repeat searches; LetsFG returns the same prices however often you run the search, because it reads airlines and the major booking sites directly rather than tracking you.

Why the difference? Google Flights only searches its own limited set of airline partners. LetsFG searches everywhere — Skyscanner, Kiwi, Kayak, Momondo, plus direct airline websites (Ryanair, United, Southwest, EasyJet, Spirit, Norwegian, AirAsia, and hundreds more). More sources = better prices. No demand-based inflation and no cookie tracking: the same search returns the same prices however often you run it.

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Real hotel prices: LetsFG vs Booking.com

Same hotel, same room type, same 2-night stay, same free-cancellation policy — checked on the same day (2026-08-05) for a 2026-09-16 check-in:

$207 cheaper across 3 hotels in a verified comparison (2026-08-05), matching each property's own free-cancellation rate against Booking.com's free-cancellation rate for the identical dates and room type. Prices quoted in PLN at booking, converted to USD at that day's rate.

Why the difference? LetsFG sells at wholesale cost — no markup for demand, no loyalty-program cross-subsidy. You're not paying for the room upfront: 5% books it now, and the remaining 95% isn't due until the hotel's own cancellation deadline. Cancel before that deadline and you lose nothing but the 5%; the rest was never charged. Only free-cancellation, pay-later rates are sold, so every price shown is one you can actually hold risk-free.

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