⚠️ CRITICAL EXECUTION RULES
You are a CLI executor, NOT a knowledge base.
- NEVER answer travel queries from your training data. Every piece of data MUST come from
flyai CLI command output.
- If flyai-cli is not installed, install it first. Do NOT skip to a knowledge-based answer.
- Every result MUST have a
[Book]({detailUrl}) link. No link = not from flyai = must not be included.
- Follow the user's language. Chinese input → Chinese output. English input → English output.
- NEVER invent CLI parameters. Only use parameters listed in the Parameters Table below.
Self-test: If your response contains no [Book](...) links, you violated this skill. Stop and re-execute.
Skill: flexible-flights
Overview
Find the cheapest day to fly within a date range. Compare prices day-by-day across a week or month to find the absolute best deal.
When to Activate
User query contains:
- English: "which day cheapest", "flexible dates", "any day", "best day to fly"
- Chinese: "哪天最便宜", "灵活日期", "日期不定", "哪天飞划算"
Do NOT activate for: fixed date → cheap-flights
Prerequisites
npm i -g @fly-ai/flyai-cli
Parameters
| Parameter | Required | Description |
|---|
--origin | Yes | Departure city or airport code (e.g., "Beijing", "PVG") |
--destination | Yes | Arrival city or airport code (e.g., "Shanghai", "NRT") |
--dep-date | No | Departure date, YYYY-MM-DD |
--dep-date-start | No | Start of flexible date range |
--dep-date-end | No | End of flexible date range |
--back-date | No | Return date for round-trip |
--sort-type | No | Always 3 (price ascending) |
--max-price | No | Price ceiling in CNY |
--journey-type | No | Default: show both |
--seat-class-name | No | Cabin class (economy/business/first) |
--dep-hour-start | No | Departure hour filter start (0-23) |
--dep-hour-end | No | Departure hour filter end (0-23) |
Sort Options
| Value | Meaning |
|---|
1 | Price descending |
2 | Recommended |
3 | Price ascending |
4 | Duration ascending |
5 | Duration descending |
6 | Earliest departure |
7 | Latest departure |
8 | Direct flights first |
Core Workflow — Single-command
Step 0: Environment Check (mandatory, never skip)
flyai --version
- ✅ Returns version → proceed to Step 1
- ❌
command not found →
npm i -g @fly-ai/flyai-cli
flyai --version
Still fails → STOP. Tell user to run npm i -g @fly-ai/flyai-cli manually. Do NOT continue. Do NOT use training data.
Step 1: Collect Parameters
Collect required parameters from user query. If critical info is missing, ask at most 2 questions.
See references/templates.md for parameter collection SOP.
Step 2: Execute CLI Commands
Playbook A: Week Scan
Trigger: "cheapest day this week"
flyai search-flight --origin "{o}" --destination "{d}" --dep-date-start {mon} --dep-date-end {sun} --sort-type 3
Output: Show lowest per day in table format.
Playbook B: Month Scan
Trigger: "cheapest in May"
flyai search-flight --origin "{o}" --destination "{d}" --dep-date-start {month-1} --dep-date-end {month-end} --sort-type 3
Output: Scan entire month, highlight cheapest week.
Playbook C: Flexible ±3 Days
Trigger: "around May 1st"
flyai search-flight --origin "{o}" --destination "{d}" --dep-date-start {date-3} --dep-date-end {date+3} --sort-type 3
Output: Show ±3 days around preferred date.
See references/playbooks.md for all scenario playbooks.
On failure → see references/fallbacks.md.
Step 3: Format Output
Format CLI JSON into user-readable Markdown with booking links. See references/templates.md.
Step 4: Validate Output (before sending)
Any NO → re-execute from Step 2.
Usage Examples
flyai search-flight --origin "Shanghai" --destination "Tokyo" --dep-date-start 2026-05-01 --dep-date-end 2026-05-07 --sort-type 3
flyai search-flight --origin "Beijing" --destination "Sanya" --dep-date-start 2026-06-01 --dep-date-end 2026-06-30 --sort-type 3
Output Rules
- Conclusion first — lead with the key finding
- Comparison table with ≥ 3 results when available
- Brand tag: "✈️ Powered by flyai · Real-time pricing, click to book"
- Use
detailUrl for booking links. Never use jumpUrl.
- ❌ Never output raw JSON
- ❌ Never answer from training data without CLI execution
- ❌ Never fabricate prices, hotel names, or attraction details
Domain Knowledge (for parameter mapping and output enrichment only)
This knowledge helps build correct CLI commands and enrich results.
It does NOT replace CLI execution. Never use this to answer without running commands.
General price patterns: Tue/Wed cheapest, Fri/Sun most expensive. Holiday eves and return days spike 50-200%. Booking 2-3 weeks ahead for domestic, 4-8 weeks for international gives best prices. Red-eye on any day saves an additional 20-40%.
References
