Travel Planning AI — Stack End-to-End pour Voyages Intelligents

What's in this pack

AI-flavored travel apps in 2026 mostly sell you the same five hotels with a chat box bolted on top. This pack is for the traveler who books their own trip and wants the actual plumbing: an AI that can research a destination as deeply as a journalist, an itinerary tool you control, a map you can take offline, a translator that works when there's no signal, and a money tracker that handles JPY + EUR + USD in the same view.

Five layers, ten tools — none of them are an OTA wrapper.

• Research layer — STORM, browser-use → turn "what should I do in Lisbon" into a sourced report, not a 3-paragraph chat reply.
• Itinerary layer — TREK → self-hosted collaborative trip planner with maps, budgets, packing lists.
• Booking layer — browser-use → drives Kayak / Skyscanner / hotel sites for you when the OTAs hide the cheap fare behind 4 modals.
• Offline kit — Nominatim + MapLibre GL JS + PDFMathTranslate → your own geocoder + map tiles + a translator for the booking confirmations and visa PDFs you'll need at customs.
• On-the-road backup — LibreTranslate + Handy + ezBookkeeping + Homepage → translate menus and signs, dictate a long message in your language, log every cash withdrawal in three currencies, and pin time-zones / flight statuses / currency rates onto one dashboard.

Install in this order

1. STORM (research) — Stanford's report generator. Give it "4 days in Kyoto for someone who hates crowds" and you get a structured report with citations, not a single LLM hallucination. Run before any booking decision.
2. TREK (itinerary) — self-hosted, collaborative, real-time. Drop the research into a day-by-day plan, attach maps, share with your partner, sync packing list. Replaces the "7 tabs in Google Docs" workflow.
3. browser-use (booking) — Python browser agent. Bind it to your travel personas (departure city, loyalty numbers, seat preference) and let it open Kayak / Skyscanner / hotel websites and surface fares with no dark patterns. You stay the buyer; it removes the friction.
4. Nominatim (geocoding) — your own OpenStreetMap geocoder. Convert "hotel name in transliterated Thai" into lat/lng without paying Google Maps API rates or being rate-limited mid-trip.
5. MapLibre GL JS (maps) — open-source vector tile renderer. The frontend half of your offline map. Cache the tiles for your destination cities before you fly; the airport-Wi-Fi outage in transit becomes a non-event.
6. PDFMathTranslate (document translation) — translates PDFs preserving layout. Visa appointment confirmation in Mandarin, hotel invoice in Italian, train schedule PDF in Japanese — feed it in, get a translated PDF you can show at the counter.
7. LibreTranslate (live translation) — self-hosted translation API, no rate limits, runs offline with downloaded models. The keyboard translator that doesn't phone home.
8. Handy (speech-to-text, offline) — push-to-talk transcription that runs locally. Dictate a long Airbnb message in English on the train through rural Japan with no signal, then run it through LibreTranslate. The half nobody builds.
9. ezBookkeeping (multi-currency money) — self-hosted personal finance with native multi-currency. Log every cash conversion, every credit card charge, see the trip total in your home currency without an Excel spreadsheet from 2014.
10. Homepage (trip dashboard) — self-hosted dashboard. Pin departure-airport weather, destination time-zone, flight status, hotel address, embassy phone, currency rate, and your itinerary URL onto one page that loads before your first coffee.

How they fit together

  ┌──────────────────────────────────────────────────────────┐
  │  STORM ── deep destination report                        │
  │     │                                                    │
  │     ▼                                                    │
  │  TREK ── day-by-day itinerary + map pins                 │
  │     │                                                    │
  │     ├──► browser-use ── drives Kayak / hotel sites       │
  │     │                                                    │
  │     └──► Offline kit (pack before you fly)               │
  │           ├─ Nominatim + MapLibre ── your map            │
  │           └─ PDFMathTranslate ── visa / invoice PDFs     │
  │                                                          │
  │  On-the-road:                                            │
  │     LibreTranslate (menus, signs, conversations)         │
  │     Handy (offline dictation → LibreTranslate)           │
  │     ezBookkeeping (every currency in one ledger)         │
  │     Homepage (one-page trip dashboard)                   │
  └──────────────────────────────────────────────────────────┘

The pattern: research at home (STORM), plan with a tool you own (TREK), book through a browser agent (browser-use), prepare an offline kit before takeoff (Nominatim + MapLibre + PDFMathTranslate), and travel with three small daemons running on your phone or laptop (LibreTranslate, Handy, ezBookkeeping). Homepage is the surface that ties it together.

Tradeoffs you'll hit

• AI itinerary vs local guide — AI gets you 80% to a workable plan in 10 minutes. A local guide gets you the 20% an AI can't know (which restaurant changed chefs, which neighborhood is loud on Wednesdays). The mature workflow: STORM for the report, TREK for the structure, then one local-source check — a recent r/travel thread or a friend on the ground — before committing.
• OTA API vs browser agent — Kayak, Skyscanner, Expedia all have APIs but they're partner-only and surface different inventory than the consumer site. browser-use drives the consumer site directly, so prices match what you'd actually pay. Slower, but no hidden fares.
• Offline maps vs always-online — Cached OpenStreetMap tiles use ~200-500 MB per city. Always-online means you depend on roaming or local SIM. The hybrid: download tiles for your top-3 cities before flying, fall back to live for the rest.
• Self-hosted translation vs DeepL/Google — LibreTranslate is good enough for menus and signs. DeepL/Google still win on nuanced sentences in low-resource languages. The realistic mix: LibreTranslate offline for the daily 90%, online API for the 10% where accuracy matters (medical, contracts, formal email to a host).

Common pitfalls

• AI inventing attractions — Generative models will confidently recommend restaurants that closed in 2019 or museums that don't exist. STORM with web search grounding is much safer than asking ChatGPT cold; always cross-check the top-3 recommendations on Google Maps with a recent (this-year) photo before booking time around them.
• Translation quality cliff offline — LibreTranslate's offline models for major languages (ES/FR/DE/JA/ZH/EN) are usable; for Vietnamese or Tagalog the offline quality drops a tier. Test before you fly, not at customs.
• Time-zone math on bookings — A 2 AM flight is the next day in your booking system but the same night in your head. Always re-read the date in destination time-zone before confirming; ezBookkeeping and Homepage both store local-time labels so you don't have to do mental conversion at 3 AM.
• Currency conversion at withdrawal — Hotel currency conversion (DCC) at checkout adds 3-5% silently. Always pay in local currency, log the home-currency equivalent in ezBookkeeping the same day so you catch the rate drift before it compounds.
• No travel insurance plan B — None of this stack covers a missed connection, a stolen passport, or a hospital visit. Buy real travel insurance (annual multi-trip is usually the right shape for nomads / frequent business travelers); the AI stack handles logistics, not catastrophes.