GTFS Fares Assistant

A frontend-only React + TypeScript + Tailwind CSS app to build GTFS Fares V2 files — fare_media.txt, rider_categories.txt and fare_products.txt — entirely in the browser. No backend, no data leaves your machine.

One optional exception: the Fill data with AI feature (below) sends the documents you attach directly from your browser to the Anthropic (Claude) API, using your own API key. It is opt-in and clearly flagged; everything else runs fully offline.

Available in English and French — it defaults to the browser language and your choice is remembered.

Workflow

1. Network name — used to name the downloaded zip (e.g. my_city_transit_gtfs_fares.zip).
2. Import (optional) — load an existing GTFS zip to edit; it is unzipped in the browser and reconstructed into the editor.
3. Supports (fare media) — pick the fare_media_type first (this drives the name/id placeholders), then name it. The id auto-fills from the name but stays fully editable.
4. Rider categories & conditions — optional rider groups (Adult, Youth, Senior…) that a product can target → rider_categories.txt (rider_category_id, rider_category_name, is_default_fare_category, eligibility_url). At most one category can be the default. Age eligibility is not part of the adopted spec, so it is expressed via eligibility_url.
5. Products — define fare products (fare_product_id, name, amount, currency), pick which supports each is usable on, and optionally target a rider category. Each product may also carry optional leg & transfer rules (see below).
6. Preview & download — live preview of each .txt file; download them individually or all together as a zip (built in-browser with JSZip).

Fill data with AI (optional)

Instead of typing everything by hand, you can let Claude read your fare schedule and pre-fill the supports, rider categories and products for you:

1. Click Ask AI to fill in data from my fare schedule.
2. Paste your own Anthropic API key (create one at console.anthropic.com). It is stored only in this browser's localStorage.
3. Attach one or more PDF, image (PNG/JPG…) or Excel/CSV files describing the fares. PDFs and images are sent to Claude natively; Excel files are converted to CSV in your browser first (via SheetJS).
4. Pick a model — Claude Sonnet 5 (default, faster & cheaper) or Claude Opus 4.8 (highest accuracy for hard documents).
5. Click Extract. The result replaces the current data (with the usual confirm-before-replace guard) and lands in the normal editor, where you review and correct everything before downloading.

The extraction runs directly from your browser against the Anthropic API with your key — no server of ours is involved — and the heavy SDK is only downloaded the first time you run an extraction. The AI can make mistakes: ids, prices and currencies are always yours to verify, and any that look off are flagged in a review list.

Leg & transfer rules (optional)

A product can optionally emit fare_leg_rules.txt and fare_transfer_rules.txt to express how many transfers are allowed and how long the ticket is valid. Kept deliberately simple — no network / area / timeframe support:

• one leg group per product (transfers apply within the same product);
• transfers are always free (fare_transfer_type = 0, no transfer product);
• transfers: none, a fixed count, or unlimited (transfer_count = -1);
• validity: an optional duration entered in minutes (written to the file in seconds), with a selectable duration_limit_type (0–3).

Example — a 3-hour ticket with unlimited transfers: transfers unlimited, duration 180 min → transfer_count = -1, duration_limit = 10800. These two files are only emitted when at least one product defines them.

Everything you enter is saved to localStorage, so you can leave and come back to keep editing.

Validation

• Currency must be an active ISO 4217 code.
• Amount must be a non-negative number whose decimal places fit the currency's minor unit (e.g. JPY → 0, BHD → 3).
• Ids must be unique and CSV-safe (no spaces, commas or quotes).
• At most one rider category may be marked as the default (is_default_fare_category).

How multi-support products are encoded

A product usable on several supports produces one row per support in fare_products.txt (same fare_product_id, different fare_media_id) — the standard GTFS Fares V2 way to express multi-media validity. A product with no support selected produces a single row with an empty fare_media_id. A targeted rider category is written to the rider_category_id column on every row of that product. References to a deleted support or category are dropped from the output.

Develop

npm install
npm run dev      # start Vite dev server
npm run build    # type-check + production build to dist/
npm run preview  # preview the production build

The Vite base is set to ./ (relative assets) so the build works from any sub-path, including a GitHub Pages project site.

Deploy (GitHub Pages)

Pushing to main triggers .github/workflows/deploy.yml, which builds the app and publishes dist/ to GitHub Pages. Enable it once under Settings → Pages → Build and deployment → Source: GitHub Actions.