# Chicago Transit Authority

**Canonical:** https://apis.io/providers/chicago-transit-authority/  
**Website:** https://www.transitchicago.com/  
**APIs profiled:** 11

The Chicago Transit Authority (CTA) is the public transit operator for the City of Chicago and 35 surrounding suburbs, operating the second largest public transit system in the United States with bus and rapid-transit (L) train services. The CTA Developer Center publishes open transit data feeds and APIs for developers building rider-facing applications, including the Train Tracker API for real-time L-train arrivals, the Bus Tracker API for real-time bus arrivals and vehicle locations, the Customer Alerts API for service status and disruptions, and GTFS schedule data feeds for the entire CTA bus and rail network.

## Kin Score — 38.1 / 100 (thin)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 38.1).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 57.3 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 7.9 |
| Developer Ergonomics | 21.4 |
| Commercial Clarity | 36.8 |
| Access Clarity | 36.8 |

Regulatory layer — **Government & Public Sector**: 46.3 (matched via tags).

## Agent readiness — 34.7 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | na |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | na |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | na |

## Access

Freemium · Self-serve signup — onboarding: self-serve, pricing: freemium, trial: no (confidence: high).

## APIs (11)

- **CTA Customer Alerts API** — The Customer Alerts API delivers real-time service status, planned outages, and disruption information for CTA bus and rail services. It provides both a route-level status feed ...
- **CTA GTFS Schedule Feed** — CTA publishes a GTFS (General Transit Feed Specification) schedule feed covering the physical layout, stop locations, and static schedules for the entire CTA bus and L train sys...
- **Chicago Transit Authority Arrivals API** — Train arrival prediction operations
- **Chicago Transit Authority Bulletins API** — The Bulletins API from Chicago Transit Authority — 1 operation(s) for bulletins.
- **Chicago Transit Authority Follow API** — Follow an individual train run
- **Chicago Transit Authority Locations API** — Train geolocation operations
- **Chicago Transit Authority Predictions API** — The Predictions API from Chicago Transit Authority — 1 operation(s) for predictions.
- **Chicago Transit Authority Routes API** — The Routes API from Chicago Transit Authority — 3 operation(s) for routes.
- **Chicago Transit Authority Stops API** — The Stops API from Chicago Transit Authority — 1 operation(s) for stops.
- **Chicago Transit Authority System API** — The System API from Chicago Transit Authority — 1 operation(s) for system.
- **Chicago Transit Authority Vehicles API** — The Vehicles API from Chicago Transit Authority — 1 operation(s) for vehicles.

## Agentic access (1)

- **Chicago Transit Authority Agentic Access** — 11 operations

## Security (2)

- **Chicago Transit Authority Authentication** — apiKey · 1 scheme
- **Chicago Transit Authority Domain Security** — TLSv1.3 · HSTS

## Plans (1)

- **Chicago Transit Authority Plans Pricing**

## Use cases (9)

- **Rider-Facing Mobile Apps**
- **Trip Planners and Routing**
- **Real-Time Arrival Displays**
- **Service Disruption Notifications**
- **Schedule Visualizations**
- **Accessibility Tooling**
- **Smart City Dashboards**
- **Multimodal Transit Apps**
- **Research and Open Data Analysis**

## Tags

Bus, Bus Tracker, Chicago, CTA, Customer Alerts, GTFS, L Train, Open Data, Public Transit, Real-Time, Train, Train Tracker, Transit, Transportation

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/chicago-transit-authority/). Scores are computed from the provider's own public artifacts under a published rubric.