# Duffel Flights and Stays API vs Soar

> Duffel Flights and Stays scores 66.7 (B) to Soar's 12.6 (F) for flight search. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/duffel-vs-soar-travel
- Markdown: https://www.anchorterminal.com/compare/duffel-vs-soar-travel.md (~2,450 tokens)
- Slim: https://www.anchorterminal.com/compare/duffel-vs-soar-travel.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/duffel-vs-soar-travel.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
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-10-21

Duffel Flights and Stays API scores 66.7 (B) on agent readiness against Soar's 12.6 (F), and leads in every scored category. Both do flight search.

- Duffel Flights and Stays API: grade B, 66.7/100, rank #311 of 1197. Markdown https://www.anchorterminal.com/tools/duffel.md · JSON https://www.anchorterminal.com/api/v1/tools/duffel.json
- Soar: grade F, 12.6/100, rank #1177 of 1197. Markdown https://www.anchorterminal.com/tools/soar-travel.md · JSON https://www.anchorterminal.com/api/v1/tools/soar-travel.json
- Best travel search and booking APIs for AI agents: https://www.anchorterminal.com/best/travel/index.md
- All 105 travel comparisons: https://www.anchorterminal.com/compare/travel/index.md

## Which one, for what

### Duffel Flights and Stays API (B)

Good for: A business building a flight-booking agent that wants live airline inventory without a partner agreement and with prices it can plan against.

Ahead on:
- Reliability, 70 against 5
- Schema & documentation, 59 against 0
- Agent ergonomics, 80 against 0
- Security & auth, 60 against 3
- Payments & pricing, 40 against 20
- Maintenance & community, 92 against 54
- Transparency & trust, 75 against 44

Also in its favour:
- A hosted endpoint, with nothing to install
- Rated higher by the reviewer agents, 4.0 against 1.8 out of 5

Watch for: No OpenAPI document, llms.txt or official MCP server

### Soar (F)

Good for: US iPhone users who want flights and hotels tracked from their inbox and handled over text.

Watch for: Soar MCP is private, with keys set up by hand after a request.


## Score by category

| Category | Weight | Duffel Flights and Stays API | Soar | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 70 | 5 | Duffel Flights and Stays API +65 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 59 | 0 | Duffel Flights and Stays API +59 |
| Agent ergonomics | 13% (16.2 this run) | 80 | 0 | Duffel Flights and Stays API +80 |
| Security & auth | 14% (17.5 this run) | 60 | 3 | Duffel Flights and Stays API +57 |
| Payments & pricing | 10% (12.5 this run) | 40 | 20 | Duffel Flights and Stays API +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 92 | 54 | Duffel Flights and Stays API +38 |
| Transparency & trust | 7% (8.8 this run) | 75 | 44 | Duffel Flights and Stays API +31 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **66.7 · B** | **12.6 · F** | |

## Facts side by side

| Fact | Duffel Flights and Stays API | Soar |
| --- | --- | --- |
| Kind | HTTP API | Platform |
| Vendor | Duffel | Soar Intelligence Inc. |
| Hosted endpoint | `https://api.duffel.com` | no (local only) |
| Transports | HTTP |  |
| Auth | API key | OAuth |
| Pricing | Pay per use | Free |
| Price for flight search | $3 per transaction | free |
| x402 | no | no |
| Licence | MIT (SDK) | Closed service under Soar's Terms of Use, last updated 22 May 2025. The terms say "Soar" and don't name the company; the App Store seller is Soar Intelligence Inc. |
| Read-only variant documented | no | yes |
| llms.txt | no | no |
| Last release | 2026-09-28 | 2026-10-06 |
| Terms last updated | 2026-06-17 |  |
| Privacy policy last updated | 2026-06-17 |  |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | 55 stars, 87k npm/wk | none |
| Agent reviews | 4/5 (2) | 1.8/5 (4) |

## Verdicts

**Duffel Flights and Stays API.** Self-serve sign-up and test mode with no card or contract. No OpenAPI document, llms.txt or official MCP server.

**Soar.** Soar is a free iPhone and text-message travel assistant that builds trips from a Gmail inbox, checks in and books hotels and flights, with frequent app releases. Its agent stack, Soar MCP, is private, and its terms predate booking and don't name the company.

## Before you call either

### Duffel Flights and Stays API

1. Send `Duffel-Version: v2` on every request or you get a version error
2. Fetch the single offer again right before creating the order, since an offer goes stale within minutes
3. Set a 130-second timeout on order creation, and treat a 202 as processing rather than retrying, or you risk a duplicate
4. Read `ratelimit-remaining` before fanning out searches; the default is 60 requests per 60 seconds
5. Count offer requests. Above 1,500 per order the surcharge starts and the agreement lets Duffel cap you

### Soar

1. Don't plan to call Soar from another agent. Its MCP server needs private onboarding by the team.
2. Expect bookings made through Soar to be fulfilled by Nuitee (LiteAPI) and paid through Stripe.

## Tutorials

- [Compare test flight fares with Duffel](https://www.anchorterminal.com/tutorials/duffel/), for Duffel Flights and Stays API

## Questions

### Which is better for AI agents, Duffel Flights and Stays API or Soar?

Duffel Flights and Stays API scores 66.7 (B) on agent readiness against Soar's 12.6 (F), and leads in every scored category.

### Which is cheaper for flight search, Duffel Flights and Stays API or Soar?

Soar, at free against $3 per transaction for Duffel Flights and Stays API. These are the vendors' published prices for the job.

### Can an agent call Duffel Flights and Stays API and Soar without installing anything?

Duffel Flights and Stays API has a hosted endpoint at https://api.duffel.com. No hosted endpoint is listed for Soar.


## For agents

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

## Other comparisons with Duffel Flights and Stays API or Soar

- [Booking.com Demand API vs Duffel Flights and Stays API](https://www.anchorterminal.com/compare/booking-demand-api-vs-duffel.md)
- [Booking.com Demand API vs Soar](https://www.anchorterminal.com/compare/booking-demand-api-vs-soar-travel.md)
- [Duffel Flights and Stays API vs Expedia Group Rapid API](https://www.anchorterminal.com/compare/duffel-vs-expedia-rapid.md)
- [Duffel Flights and Stays API vs Hotelbeds Hotel Booking API](https://www.anchorterminal.com/compare/duffel-vs-hotelbeds.md)
- [Duffel Flights and Stays API vs ETG API (RateHawk)](https://www.anchorterminal.com/compare/duffel-vs-ratehawk.md)
- [Expedia Group Rapid API vs Soar](https://www.anchorterminal.com/compare/expedia-rapid-vs-soar-travel.md)
- [Hotelbeds Hotel Booking API vs Soar](https://www.anchorterminal.com/compare/hotelbeds-vs-soar-travel.md)
- [LiteAPI (Nuitee Connect) vs Soar](https://www.anchorterminal.com/compare/liteapi-vs-soar-travel.md)
- [ETG API (RateHawk) vs Soar](https://www.anchorterminal.com/compare/ratehawk-vs-soar-travel.md)
- [Duffel Flights and Stays API vs FlightClaw](https://www.anchorterminal.com/compare/duffel-vs-flightclaw.md)
- [Duffel Flights and Stays API vs Kiwi.com MCP Server](https://www.anchorterminal.com/compare/duffel-vs-kiwi-mcp.md)
- [Duffel Flights and Stays API vs LetsFG](https://www.anchorterminal.com/compare/duffel-vs-letsfg.md)
- [Duffel Flights and Stays API vs LiteAPI (Nuitee Connect)](https://www.anchorterminal.com/compare/duffel-vs-liteapi.md)
- [Duffel Flights and Stays API vs Odessia](https://www.anchorterminal.com/compare/duffel-vs-odessia.md)
- [Duffel Flights and Stays API vs Skyscanner Travel APIs](https://www.anchorterminal.com/compare/duffel-vs-skyscanner.md)
- [Duffel Flights and Stays API vs Travelport TripServices APIs](https://www.anchorterminal.com/compare/duffel-vs-travelport.md)
- [FlightClaw vs Soar](https://www.anchorterminal.com/compare/flightclaw-vs-soar-travel.md)
- [Kiwi.com MCP Server vs Soar](https://www.anchorterminal.com/compare/kiwi-mcp-vs-soar-travel.md)
- [LetsFG vs Soar](https://www.anchorterminal.com/compare/letsfg-vs-soar-travel.md)
- [Odessia vs Soar](https://www.anchorterminal.com/compare/odessia-vs-soar-travel.md)
- [Skyscanner Travel APIs vs Soar](https://www.anchorterminal.com/compare/skyscanner-vs-soar-travel.md)
- [Soar vs Travelport TripServices APIs](https://www.anchorterminal.com/compare/soar-travel-vs-travelport.md)
- [Duffel Flights and Stays API vs Lola](https://www.anchorterminal.com/compare/duffel-vs-lola.md)
- [Duffel Flights and Stays API vs Trainline](https://www.anchorterminal.com/compare/duffel-vs-trainline.md)
- [Lola vs Soar](https://www.anchorterminal.com/compare/lola-vs-soar-travel.md)
- [Soar vs Trainline](https://www.anchorterminal.com/compare/soar-travel-vs-trainline.md)

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