@stiava/cta - Chicago Transit Application SDK

A modern TypeScript client for the Chicago Transit Authority (CTA) Bus Tracker and Train Tracker APIs.

Designed for Node.js, Next.js, and modern JavaScript applications, this package provides a simple, strongly typed interface for accessing real-time CTA transit data.

Key Features

• 🚌 CTA Bus Tracker client
• 🚆 CTA Train Tracker client
• 📍 CTA systems routes, map files, and stops
• 🚲 Divvy stations data and realtime rack counts.
• 🚘 Guide to Chicago roads. Interstates, primary roads, awkward turns, and one-way neighborhoods.
• 🅿️ Chicago Parking Guide: Paid streets, residential permits, and enforcement data(ProPublica).
• 📝 Full TypeScript support
• 🌐 Works in Node.js and modern web frameworks

Installation

npm install @stiava/cta

Getting Started

import { CTA } from "@stiava/cta";

// Use the CTA apis.
const cta_buses = new CTABusService(process.env.CTA_BUS_API_KEY!);
const cta_trains = new CTATrainService(process.env.CTA_TRAIN_API_KEY!);

Train Arrivals

const arrivals = await cta.train.getArrivals({
  stationId: "40380",
});

console.log(arrivals);

Bus Arrivals

const arrivals = await cta.bus.getPredictions({
  stopId: "14787",
});

console.log(arrivals);

Find Stops

const stops = await cta.bus.getStops({
  route: "22",
});

Find Train Stations

const stations = await cta.train.getStations();

API Keys

The CTA APIs require developer API keys.

You can request free API keys from the Chicago Transit Authority Developer Center.

Once obtained, provide your keys when creating the client.

TypeScript

This package is written entirely in TypeScript and ships with complete type definitions.

import type {
  TrainArrival,
  BusPrediction,
} from "@jeremystiava/cta";

Framework Support

Works with:

• Node.js
• Next.js
• React
• Express
• NestJS
• Bun
• Deno (via npm compatibility)

Roadmap

• [ ] Route planning
• [ ] Service alerts
• [ ] Vehicle tracking
• [ ] GTFS static data helpers
• [ ] Automatic retry/backoff
• [ ] Built-in caching
• [ ] Rate limit handling

Contributing

Contributions, issues, and feature requests are welcome.

If you'd like to contribute, please open an issue or submit a pull request.

License

MIT © Jeremy Stiava