Agent skill

Duffel

by borski in borski/travel-hacking-toolkit

Real-time GDS flight search via Duffel API. An agent skill from borski/travel-hacking-toolkit.

MITAuto-check passed

Install Duffel

skills CLI

$ npx skills add borski/travel-hacking-toolkit --skill duffel -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install borski/travel-hacking-toolkit duffel --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/borski/travel-hacking-toolkit.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/travel-hacking-toolkit/skills/duffel .claude/skills/duffel && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "duffel" agent skill from https://github.com/borski/travel-hacking-toolkit/tree/main/plugins/travel-hacking-toolkit/skills/duffel into .claude/skills/duffel/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "duffel", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/borski/travel-hacking-toolkit/tree/main/plugins/travel-hacking-toolkit/skills/duffel

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add borski/travel-hacking-toolkit --skill duffel -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install borski/travel-hacking-toolkit duffel --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/borski/travel-hacking-toolkit.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/travel-hacking-toolkit/skills/duffel .agents/skills/duffel && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "duffel" agent skill from https://github.com/borski/travel-hacking-toolkit/tree/main/plugins/travel-hacking-toolkit/skills/duffel into .agents/skills/duffel/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "duffel", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add borski/travel-hacking-toolkit --skill duffel -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install borski/travel-hacking-toolkit duffel --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/borski/travel-hacking-toolkit.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/travel-hacking-toolkit/skills/duffel .cursor/skills/duffel && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "duffel" agent skill from https://github.com/borski/travel-hacking-toolkit/tree/main/plugins/travel-hacking-toolkit/skills/duffel into .cursor/skills/duffel/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "duffel", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/borski/travel-hacking-toolkit.git --path plugins/travel-hacking-toolkit/skills/duffel

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add borski/travel-hacking-toolkit --skill duffel -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install borski/travel-hacking-toolkit duffel --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/borski/travel-hacking-toolkit.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/travel-hacking-toolkit/skills/duffel .gemini/skills/duffel && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "duffel" agent skill from https://github.com/borski/travel-hacking-toolkit/tree/main/plugins/travel-hacking-toolkit/skills/duffel into .gemini/skills/duffel/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "duffel", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install borski/travel-hacking-toolkit duffel

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add borski/travel-hacking-toolkit --skill duffel -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/borski/travel-hacking-toolkit.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/travel-hacking-toolkit/skills/duffel .github/skills/duffel && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "duffel" agent skill from https://github.com/borski/travel-hacking-toolkit/tree/main/plugins/travel-hacking-toolkit/skills/duffel into .github/skills/duffel/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "duffel", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add borski/travel-hacking-toolkit --skill duffel -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install borski/travel-hacking-toolkit duffel --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/borski/travel-hacking-toolkit.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/travel-hacking-toolkit/skills/duffel .opencode/skills/duffel && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "duffel" agent skill from https://github.com/borski/travel-hacking-toolkit/tree/main/plugins/travel-hacking-toolkit/skills/duffel into .opencode/skills/duffel/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "duffel", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: duffel
GitHub stars: 688
Token cost: ~1.9k tokens
SKILL.md length: 264 words
Files: 1
Skills in repo: 46
Repo updated: Oct 5, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Real-time GDS flight search via Duffel API. An agent skill from borski/travel-hacking-toolkit.

SKILL.md covers Prerequisites, API Basics, Search Flights (One-Way) and Search Flights (Round-Trip), plus 10 more sections
Calls curl and jq; reaches api.duffel.com

What it does

Duffel is an agent skill from borski/travel-hacking-toolkit. Real-time GDS flight search via Duffel API. Accurate per-fare-class pricing, cabin selection, multi-city, time preferences. Primary cash price source. Does not include Southwest.

Its SKILL.md is about 1.9k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

The repository describes itself as: AI-powered travel hacking and search with cash, points, miles, and award flights. Drop-in skills and MCP servers for Claude, Codex, and OpenCode. The licence is MIT.

Example prompts

“/duffel”

Requirements

Pre-approved tools (allowed-tools): Bash(curl *)

What it can do on your machine

Read from SKILL.md and the folder at commit db82131. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
- Bash(curl *)
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- curl
- jq
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
- api.duffel.com
Also links to:
- duffel.com
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Duffel loads about 1.9k tokens when it runs. Until then it costs about 46 tokens; SKILL.md has 264 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~46
When it runs · the whole SKILL.md, loaded when a task matches: ~1.9k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from borski/travel-hacking-toolkit at commit db82131, republished under its MIT licence (© borski). 264 words, ~1,865 tokens.

Download SKILL.mdSave it as .claude/skills/duffel/SKILL.md (or your agent's skills folder).

name: duffel
description: Real-time GDS flight search via Duffel API. Accurate per-fare-class pricing, cabin selection, multi-city, time preferences. Primary cash price source. Does not include Southwest.
allowed-tools: Bash(curl *)
category: flights
summary: Primary cash prices. Real GDS per-fare-class data.
api_key: Duffel

Duffel Flights

Search for real-time flight offers across airlines via the Duffel API. Returns live pricing, cabin details, baggage info, and booking links. Supports one-way, round-trip, and multi-city searches.

Source: duffel.com

Prerequisites

DUFFEL_API_KEY_LIVE environment variable set with a live API token
Token needs air.offer_requests.create permission

API Basics

Base URL: https://api.duffel.com
Version header: Duffel-Version: v2 (REQUIRED, v1 is deprecated)
Auth: Authorization: Bearer $DUFFEL_API_KEY_LIVE
Content-Type: application/json
Rate limit: 60 requests per 60 seconds

Search Flights (One-Way)

bash

curl -s -X POST "https://api.duffel.com/air/offer_requests?return_offers=true&supplier_timeout=15000" \
  -H "Accept: application/json" \
  -H "Duffel-Version: v2" \
  -H "Authorization: Bearer $DUFFEL_API_KEY_LIVE" \
  -H "Content-Type: application/json" \
  -d '{
    "data": {
      "slices": [{
        "origin": "SFO",
        "destination": "NRT",
        "departure_date": "2026-08-15"
      }],
      "passengers": [{"type": "adult"}],
      "cabin_class": "economy"
    }
  }'

Search Flights (Round-Trip)

Add a second slice with origin/destination reversed:

bash

curl -s -X POST "https://api.duffel.com/air/offer_requests?return_offers=true&supplier_timeout=15000" \
  -H "Accept: application/json" \
  -H "Duffel-Version: v2" \
  -H "Authorization: Bearer $DUFFEL_API_KEY_LIVE" \
  -H "Content-Type: application/json" \
  -d '{
    "data": {
      "slices": [
        {
          "origin": "SFO",
          "destination": "NRT",
          "departure_date": "2026-08-15"
        },
        {
          "origin": "NRT",
          "destination": "SFO",
          "departure_date": "2026-08-22"
        }
      ],
      "passengers": [{"type": "adult"}],
      "cabin_class": "business"
    }
  }'

Search Flights (Multi-City)

Add as many slices as needed:

bash

curl -s -X POST "https://api.duffel.com/air/offer_requests?return_offers=true&supplier_timeout=15000" \
  -H "Accept: application/json" \
  -H "Duffel-Version: v2" \
  -H "Authorization: Bearer $DUFFEL_API_KEY_LIVE" \
  -H "Content-Type: application/json" \
  -d '{
    "data": {
      "slices": [
        {"origin": "SFO", "destination": "NRT", "departure_date": "2026-08-15"},
        {"origin": "NRT", "destination": "ICN", "departure_date": "2026-08-20"},
        {"origin": "ICN", "destination": "SFO", "departure_date": "2026-08-25"}
      ],
      "passengers": [{"type": "adult"}],
      "cabin_class": "economy"
    }
  }'

Nonstop Only

Set max_connections to 0:

bash

curl -s -X POST "https://api.duffel.com/air/offer_requests?return_offers=true&supplier_timeout=15000" \
  -H "Accept: application/json" \
  -H "Duffel-Version: v2" \
  -H "Authorization: Bearer $DUFFEL_API_KEY_LIVE" \
  -H "Content-Type: application/json" \
  -d '{
    "data": {
      "slices": [{
        "origin": "SFO",
        "destination": "NRT",
        "departure_date": "2026-08-15"
      }],
      "passengers": [{"type": "adult"}],
      "cabin_class": "business",
      "max_connections": 0
    }
  }'

Multiple Passengers

json

"passengers": [
  {"type": "adult"},
  {"type": "adult"},
  {"age": 10},
  {"type": "infant_without_seat"}
]

Use age instead of type for children to avoid passenger type mismatches between search and booking.

Time Preferences

Constrain departure or arrival times:

json

"slices": [{
  "origin": "SFO",
  "destination": "NRT",
  "departure_date": "2026-08-15",
  "departure_time": {"from": "08:00", "to": "14:00"},
  "arrival_time": {"from": "06:00", "to": "18:00"}
}]

Query Parameters

Parameter	Default	Description
`return_offers`	`true`	Set to `false` to get just the request ID, then fetch offers separately
`supplier_timeout`	`20000`	Max ms to wait for airline responses (2000 to 60000)

Reading the Response

The response is nested under data. Key fields:

data.id                              -> offer request ID
data.offers[]                        -> array of flight offers
  .id                                -> offer ID (use to get details or book)
  .total_amount / .total_currency    -> total price
  .base_amount / .base_currency      -> base fare (before tax)
  .tax_amount / .tax_currency        -> taxes
  .owner.name                        -> airline selling this
  .expires_at                        -> when offer expires
  .slices[]                          -> journey legs
    .origin.iata_code                -> departure airport
    .destination.iata_code           -> arrival airport
    .duration                        -> e.g. "PT11H30M"
    .segments[]                      -> individual flights
      .marketing_carrier.name        -> airline name
      .marketing_carrier_flight_number
      .operating_carrier.name        -> actual operating airline
      .departing_at / .arriving_at   -> datetime
      .duration                      -> segment duration
      .origin.iata_code / .destination.iata_code
      .passengers[].cabin_class      -> economy/business/first
      .passengers[].cabin.amenities  -> wifi, power, seat info
      .passengers[].baggages[]       -> checked/carry_on allowances
  .conditions                        -> refund/change policies
    .refund_before_departure.allowed
    .change_before_departure.allowed
    .change_before_departure.penalty_amount

Get Offer Details

Retrieve full details for a specific offer:

bash

curl -s "https://api.duffel.com/air/offers/$OFFER_ID" \
  -H "Accept: application/json" \
  -H "Duffel-Version: v2" \
  -H "Authorization: Bearer $DUFFEL_API_KEY_LIVE"

Parsing Tips

Extract the 5 cheapest offers with jq:

bash

| jq '[.data.offers | sort_by(.total_amount | tonumber) | .[:5][] | {
  price: (.total_amount + " " + .total_currency),
  airline: .owner.name,
  route: [.slices[] | (.origin.iata_code + " -> " + .destination.iata_code)],
  segments: [.slices[].segments[] | {
    flight: (.marketing_carrier.iata_code + .marketing_carrier_flight_number),
    carrier: .operating_carrier.name,
    depart: .departing_at,
    arrive: .arriving_at,
    cabin: .passengers[0].cabin_class,
    duration: .duration
  }],
  stops: ([.slices[].segments | length] | map(. - 1)),
  expires: .expires_at
}]'

Cabin Classes

Value	Description
`economy`	Standard economy
`premium_economy`	Premium economy
`business`	Business class
`first`	First class

Important Notes

Offers expire quickly (usually 15 to 30 minutes). Check expires_at.
Always show the operating carrier name (US DOT regulation).
Set supplier_timeout lower than your HTTP client timeout.
Use age for child passengers instead of type to avoid airline mismatch errors.
The API returns real GDS prices. These are bookable, not estimates.
Duffel aggregates across multiple airlines in a single search.

Files

Just SKILL.md in plugins/travel-hacking-toolkit/skills/duffel of borski/travel-hacking-toolkit.

Open the folder on GitHubat commit db82131

Compare with similar skills

Duffel next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Duffel compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Duffel this skillborski/travel-hacking-toolkit	688	—	~1.9k	Automated safety check: Pass	MIT	3 days ago
Flightsasgeirtj/system_prompts_leaks	69k	—	~2.1k	Automated safety check: Pass	CC0-1.0	yesterday
Flightscodewhale-hq/Codewhale	41k	—	~258	Automated safety check: Pass	MIT	today
Duffel Flight Bookingwin4r/MuseAI-Skills	332	1 repos	~7k	Automated safety check: Pass	None	11 days ago
Flight Booking AItourmind-com/Tourmind-Booking-Skills	1.7k	—	~11k	Automated safety check: Pass	MIT	14 days ago
Navifare Flight ValidatorLeoYeAI/openclaw-master-skills	2.2k	—	~4.7k	Automated safety check: Pass	MIT	2 mo ago

Similar skills

Flights
asgeirtj/system_prompts_leaks
Research, book, or manage flights, including check-in. An agent skill from asgeirtj/system_prompts_leaks.
69k GitHub stars~2.1k tokensUpdated yesterday
Auto-check passed
Flights
codewhale-hq/Codewhale
Track flights and look up status and schedules. An agent skill from codewhale-hq/Codewhale.
41k GitHub stars~258 tokensUpdated today
Auto-check passed
Duffel Flight Booking
win4r/MuseAI-Skills
Defines how an agent searches, books and manages flights through the Duffel CLI, and watches a booked fare when you ask for ongoing price monitoring.
332 GitHub starsUsed in 1 repo~7k tokens
Productivity & AutomationAuto-check passed
Flight Booking AI
tourmind-com/Tourmind-Booking-Skills
A skill your agent uses when a user wants to resolve airports, search live flight offers, verify a selected airfare, create a flight booking, query a flight order, or safely create or query a…
1.7k GitHub stars~11k tokensUpdated 14 days ago
Auto-check passed
Navifare Flight Validator
LeoYeAI/openclaw-master-skills
Verify and compare flight prices across multiple booking sites using Navifare.
2.2k GitHub stars~4.7k tokensUpdated 2 mo ago
Auto-check passed
Flight Plan Parser
benchflow-ai/skillsbench
A skill your agent uses when converting natural language flight commands into waypoints and timing for a drone simulator.
1.8k GitHub stars~770 tokensUpdated 2 mo ago
Auto-check passed

Questions about Duffel

What does Duffel do?

Real-time GDS flight search via Duffel API. An agent skill from borski/travel-hacking-toolkit. Duffel is an agent skill from borski/travel-hacking-toolkit. Real-time GDS flight search via Duffel API.

How do I install Duffel in Claude Code?

Run `npx skills add borski/travel-hacking-toolkit --skill duffel -a claude-code`. Or copy the skill folder (plugins/travel-hacking-toolkit/skills/duffel in borski/travel-hacking-toolkit) into .claude/skills/duffel in your project. Claude Code loads it when a task matches its description.

How do I install Duffel in Codex?

Run `npx skills add borski/travel-hacking-toolkit --skill duffel -a codex`. Or copy the skill folder (plugins/travel-hacking-toolkit/skills/duffel in borski/travel-hacking-toolkit) into .agents/skills/duffel in your project. Codex loads it when a task matches its description.

Can I use Duffel in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add borski/travel-hacking-toolkit --skill duffel -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/duffel, .gemini/skills/duffel, .github/skills/duffel and .opencode/skills/duffel in your project.

What does Duffel need to run?

Going by SKILL.md and its folder, Duffel needs the command-line tools its instructions call (curl and jq). Its frontmatter pre-approves these tools: Bash(curl *).

Does Duffel access the network?

SKILL.md names 2 domains. In commands or code: api.duffel.com; the agent is likely to contact it when it follows the instructions. As links in the text: duffel.com. This is read from the text; nothing was executed.

Is Duffel safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Duffel use?

Duffel is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Duffel use?

About 1.9k tokens (SKILL.md is roughly 7.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Duffel?

Skills that share tags, products or a category with Duffel: Flights (asgeirtj/system_prompts_leaks, 69k stars), Flights (codewhale-hq/Codewhale, 41k stars), Duffel Flight Booking (win4r/MuseAI-Skills, 332 stars) and Flight Booking AI (tourmind-com/Tourmind-Booking-Skills, 1.7k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Duffel?

borski (a GitHub user) maintains it in borski/travel-hacking-toolkit, which has 688 GitHub stars. The repository holds 46 skills in this directory. The repository was last updated on October 5, 2026.

Source: borski/travel-hacking-toolkit on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Duffel

Facts

At a glance

What it does

Example prompts

Requirements

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Duffel Flights

Prerequisites

API Basics

Search Flights (One-Way)

Search Flights (Round-Trip)

Search Flights (Multi-City)

Nonstop Only

Multiple Passengers

Time Preferences

Query Parameters

Reading the Response

Get Offer Details

Parsing Tips

Cabin Classes

Important Notes

Files

Compare with similar skills

Similar skills

More from borski/travel-hacking-toolkit

Questions about Duffel