rer-web

Rewrite of the departures board for Ile-de-France Mobilites train data app from original author: https://x0r.fr.

App Preview

Live app

Stack

• Python 3.12+
• FastAPI
• Jinja templates
• Vanilla JavaScript
• Docker for deployment

What Changed

The old Perl/Dancer + PostgreSQL + GTFS import pipeline has been replaced with a smaller FastAPI app that is easier to run and maintain.

Preserved behavior:

• station selection with /?s=CODE
• live departures board
• station autocomplete
• line filtering
• saved station cookie
• compatibility endpoints: /json and /autocomp

Improvements:

• typed configuration from environment variables
• explicit handling for invalid token, rate limits, upstream failures, and empty results
• health endpoint at /health
• simpler deployment with Docker
• cleaner responsive UI
• structured Python service layer and tests

Important Migration Assumptions

• The rewrite intentionally removes the legacy PostgreSQL + GTFS schedule database to avoid the largest operational burden in the original project.
• The app still shows planned and expected departure times from the live IDFM payload when available.
• Downstream stopping patterns from the old GTFS enrichment are not rebuilt in this version, so dessertes currently falls back to Desserte indisponible.
• A compact station dataset is bundled from the legacy repository data. A small number of stations in that snapshot do not have a usable real-time stop-area reference and will return a clear message instead of departures.
• Line reference mapping is bundled from the SNCF GTFS routes dataset so line badges and filters still work without keeping a live GTFS database.

Environment Variables

Required:

• IDFM_API_TOKEN: API token for prim.iledefrance-mobilites.fr

Optional:

• APP_ENV: application environment, default development
• HOST: bind host, default 0.0.0.0
• PORT: bind port, default 8000
• LOG_LEVEL: logging level, default INFO
• DEFAULT_STATION: default station code, default GDS
• CACHE_TTL_SECONDS: upstream cache TTL, default 20
• REQUEST_TIMEOUT_SECONDS: upstream request timeout, default 8
• MAX_DEPARTURES: number of departures to display, default 6

See .env.example.

Local Run

1. Copy .env.example to .env.
2. Set IDFM_API_TOKEN in .env.
3. Install dependencies:

python -m pip install -e .[dev]

4. Start the app:

python -m app

Open http://127.0.0.1:8000.

For auto-reload during development:

python -m uvicorn app.main:app --reload --host 127.0.0.1 --port 8000

Docker

Build and run with Docker Compose:

docker compose up --build -d

Or plain Docker:

docker build -t rer-web .
docker run --env-file .env -p 8000:8000 --restart unless-stopped rer-web

The container binds to HOST and PORT from the environment. For a standard reverse proxy setup, keep HOST=0.0.0.0 and proxy to the configured PORT.

Endpoints

• /: HTML app
• /json: legacy-compatible departures JSON
• /api/departures: canonical departures JSON
• /autocomp: legacy-compatible station autocomplete JSON
• /api/stations/autocomplete: canonical station autocomplete JSON
• /health: health check

Tests

python -m pytest

Footer Credits

The footer now shows:

• ketah.info
• Original author: https://x0r.fr