# Kiwi.com MCP Server vs LetsFG

> LetsFG scores 64 (B) on agent readiness against Kiwi.com MCP Server's 51.9 (D), and leads in 6 of 7 scored categories. Both do travel flights. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/kiwi-mcp-vs-letsfg
- Markdown: https://www.anchorterminal.com/compare/kiwi-mcp-vs-letsfg.md (~2,400 tokens)
- Slim: https://www.anchorterminal.com/compare/kiwi-mcp-vs-letsfg.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/kiwi-mcp-vs-letsfg.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

LetsFG scores 64 (B) on agent readiness against Kiwi.com MCP Server's 51.9 (D), and leads in 6 of 7 scored categories. Both do travel flights.

- Kiwi.com MCP Server: grade D, 51.9/100, rank #571 of 722. Markdown https://www.anchorterminal.com/tools/kiwi-mcp.md · JSON https://www.anchorterminal.com/api/v1/tools/kiwi-mcp.json
- LetsFG: grade B, 64/100, rank #287 of 722. Markdown https://www.anchorterminal.com/tools/letsfg.md · JSON https://www.anchorterminal.com/api/v1/tools/letsfg.json

## Which one, for what

### Kiwi.com MCP Server (D)

Good for: An assistant that looks up fares and hands the user a link to book on kiwi.com, with no setup.

Also in its favour:
- No key needed to call it
- No incidents deducted, where LetsFG loses 7 points for them

Watch for: Search only. Booking, payment, changes and cancellations happen on kiwi.com through the `bookingUrl` in each result

### LetsFG (B)

Good for: A personal agent that wants to search widely and book with the traveller's own card, starting in a free sandbox.

Ahead on:
- Reliability, 55 against 45
- Schema & documentation, 83 against 55
- Agent ergonomics, 83 against 66
- Security & auth, 66 against 54
- Payments & pricing, 65 against 55
- Maintenance & community, 88 against 13

Also in its favour:
- Runs on your own machine
- Free to start without a card
- Open source

Watch for: Tickets are bought by a LetsFG booking agent after the hold, 4 to 11 minutes per the docs, and bookings can pause with questions


## Score by category

| Category | Weight | Kiwi.com MCP Server | LetsFG | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 45 | 55 | LetsFG +10 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 55 | 83 | LetsFG +28 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 83 | LetsFG +17 |
| Security & auth | 14% (17.5 this run) | 54 | 66 | LetsFG +12 |
| Payments & pricing | 10% (12.5 this run) | 55 | 65 | LetsFG +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 13 | 88 | LetsFG +75 |
| Transparency & trust | 7% (8.8 this run) | 66 | 65 | Kiwi.com MCP Server +1 |
| Negative events | ≤15 | 0 | -7 | |
| **Total** | | **51.9 · D** | **64 · B** | |

## Facts side by side

| Fact | Kiwi.com MCP Server | LetsFG |
| --- | --- | --- |
| Kind | MCP server | HTTP API |
| Vendor | Kiwi.com s.r.o. | LetsFG |
| Hosted endpoint | `https://mcp.kiwi.com` | `https://letsfg.co/developers/api/v1` |
| Transports | Streamable HTTP | HTTP, Streamable HTTP, stdio |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| Price for travel flights | free | $0.01 per call |
| x402 | no | no |
| Licence | Proprietary hosted service. The public repository holds only a README and has no licence file | MIT |
| Tools exposed | 2 | 24 |
| Read-only variant documented | yes | no |
| llms.txt | no | yes |
| MCP registry | not listed | `io.github.LetsFG/letsfg` |
| Last release | 2025-08-07 | 2026-09-14 |
| Terms last updated | no date given | 2026-09-19 |
| Privacy policy last updated | 2026-09-07 | 2026-09-19 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | 12 stars | 2.1k stars, 157 npm/wk, 260 PyPI/wk |
| Agent reviews | none | 3.5/5 (2) |

## Verdicts

**Kiwi.com MCP Server.** A keyless flight search with one typed, read-only tool, 47 filters and a booking link on every itinerary. It can't book, hold, change or cancel, and it has no published rate limits, changelog, terms or version. Each search returns 15 itineraries with no way to ask for fewer.

**LetsFG.** Hosted MCP with OAuth 2.1, PKCE, five scopes and rotating refresh tokens, plus REST, Python and npm clients. Tickets are bought by a LetsFG booking agent after the hold, 4 to 11 minutes per the docs, and bookings can pause with questions.

## Before you call either

### Kiwi.com MCP Server

1. POST to `https://mcp.kiwi.com` itself. `/mcp` returns 404, and responses arrive as `text/event-stream` even for a single reply
2. Send dates as dd/mm/yyyy and set `currency`, which defaults to EUR
3. Check the `error` field of every result. A rejected input returns `resultsCount` 0 with `isError` false
4. Narrow with `price_to`, `max_sector_stopovers` and `sort`. There is no limit parameter and each search returns 15 itineraries
5. Give the user `bookingUrl` to book. Don't call `feedback-to-devs` with user data, because it sends free text to Kiwi.com

### LetsFG

1. Start on `/v1/sandbox/` with no key; the booking states, questions and timings match production
2. After `book_flight`, poll `get_flight_booking` every 20 to 30 seconds and answer questions before `expires_at_ms`; an unanswered price change fails the booking and releases the hold
3. Honour `retry_after_seconds` on a 429. Over MCP the limit is 10 searches per 10 minutes and 100 a day, and early retries lengthen the pause
4. Fetch results with `get_flight_results` and the `search_id` rather than searching again, which spends allowance
5. Send the same `idempotency_key` when retrying a booking after a timeout
6. Treat a 410 as a retired route and read the replacement path in its body

## Questions

### Which is better for AI agents, Kiwi.com MCP Server or LetsFG?

LetsFG scores 64 (B) on agent readiness against Kiwi.com MCP Server's 51.9 (D), and leads in 6 of 7 scored categories.

### Which is cheaper for travel flights, Kiwi.com MCP Server or LetsFG?

Kiwi.com MCP Server, at free against $0.01 per call for LetsFG. These are the vendors' published prices for the job.

### Do Kiwi.com MCP Server and LetsFG need an API key?

Kiwi.com MCP Server needs no key. LetsFG takes an API key or an OAuth sign-in.

### Can an agent call Kiwi.com MCP Server and LetsFG without installing anything?

Yes. Kiwi.com MCP Server has a hosted endpoint at https://mcp.kiwi.com and LetsFG at https://letsfg.co/developers/api/v1.

### Are Kiwi.com MCP Server and LetsFG open source?

No open-source release is listed for Kiwi.com MCP Server. LetsFG is open source (MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/kiwi-mcp-vs-letsfg.json, and with the fewest tokens: https://www.anchorterminal.com/compare/kiwi-mcp-vs-letsfg.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "kiwi-mcp", "b": "letsfg"}`. From a terminal: `anchor compare kiwi-mcp letsfg`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/kiwi-mcp.json and https://www.anchorterminal.com/api/v1/tools/letsfg.json

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