Chicago Transit Authority

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.

Chicago Transit Authority publishes 9 APIs on the APIs.io network, including Arrivals API, Bulletins API, Follow API, and 6 more. Tagged areas include Bus, Bus Tracker, Chicago, CTA, and Customer Alerts.

The Chicago Transit Authority catalog on APIs.io includes 1 JSON-LD context.

Chicago Transit Authority’s developer surface includes authentication, developer portal, and 13 more developer resources.

🌐 Visit website 📡 Source on GitHub

43.7/100 developing ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6

AccessFreemiumSelf serve⚡ Free to try

11 APIs 10 Features 9 Use Cases

BusBus TrackerChicagoCTACustomer AlertsGTFSL TrainOpen DataPublic TransitReal-TimeTrainTrain TrackerTransitTransportation

Kin Score

Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6

Composite quality — 43.7/100 · developing

Contract Quality 15.7 / 25

Developer Ergonomics 3.9 / 20

Commercial Clarity 12.1 / 20

Operational Transparency 4.1 / 13

Governance 0.0 / 12

Discoverability 7.4 / 10

Agent readiness — 31/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/chicago-transit-authority: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 11

Individual APIs this provider publishes, each with its own machine-readable definition.

Rate Limits 1

Documented rate limits and quota policies.

Chicago Transit Authority Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Chicago Transit Authority Finops

FINOPS

Features 10

Notable capabilities this provider offers.

Real-Time Train Arrivals

Real-Time Bus Arrivals

Train Run Locations

Bus Vehicle Locations

Route and Stop Directories

Customer Alerts and Service Status

Planned Outage Notifications

GTFS Static Schedule Feed

API Key Issuance

Open Chicago Transit Data

Scroll for all 10

AGENTIC

Use Cases 9

What developers build with this provider.

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

Scroll for all 9

Resources

Get Started 2

Portal, sign-up, and the first successful call

Portal

Portal

ChicagoDataPortal

ChicagoDataPortal

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

JSONLD

JSONLD

Spectral

Spectral

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

APIKeyApplication

APIKeyApplication

Operate 1

Status, limits, changes, and where to get help

ContactUs

ContactUs

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 3

The organization behind the API

LinkedIn

Website

Website

Newsroom

Newsroom

Other 2

Properties that don't map to a standard resource type

SystemMap

SystemMap

Source (apis.yml)

aid: chicago-transit-authority
name: Chicago Transit Authority
kind: government
description: 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.
type: Index
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
position: Consumer
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/chicago-transit-authority.png
url: https://raw.githubusercontent.com/api-evangelist/chicago-transit-authority/refs/heads/main/apis.yml
tags:
- Bus
- Bus Tracker
- Chicago
- CTA
- Customer Alerts
- GTFS
- L Train
- Open Data
- Public Transit
- Real-Time
- Train
- Train Tracker
- Transit
- Transportation
created: '2025-05-02'
modified: '2026-05-19'
specificationVersion: '0.20'
apis:
- aid: chicago-transit-authority:customer-alerts-api
  name: CTA Customer Alerts API
  description: 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 and per-route or per-station detail. Authentication
    is not required for the public Customer Alerts feeds.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.transitchicago.com/developers/alerts/
  baseURL: http://www.transitchicago.com/api/1.0
  tags:
  - Customer Alerts
  - Real-Time
  - Service Status
  - Transit
  properties:
  - type: Documentation
    url: https://www.transitchicago.com/developers/alerts/
- aid: chicago-transit-authority:gtfs-feed
  name: CTA GTFS Schedule Feed
  description: 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 system. The feed is a downloadable ZIP archive that
    conforms to the GTFS reference and is updated when CTA service changes.
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.transitchicago.com/developers/gtfs/
  baseURL: https://www.transitchicago.com/downloads/sch_data/google_transit.zip
  tags:
  - GTFS
  - Schedule
  - Static
  - Transit
  properties:
  - type: Documentation
    url: https://www.transitchicago.com/developers/gtfs/
  - type: Feed
    url: https://www.transitchicago.com/downloads/sch_data/google_transit.zip
  - type: DataGov
    url: https://catalog.data.gov/dataset/cta-system-information-developer-tool-gtfs-data
  - type: Transitland
    url: https://www.transit.land/feeds/f-dp3-cta
  - type: ChicagoDataPortal
    url: https://data.cityofchicago.org/Transportation/CTA-System-Information-Developer-Tool-GTFS-Data/sp6w-yusg
- aid: chicago-transit-authority:chicago-transit-authority-arrivals-api
  name: Chicago Transit Authority Arrivals API
  description: Train arrival prediction operations
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Arrivals
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-arrivals-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-bulletins-api
  name: Chicago Transit Authority Bulletins API
  description: The Bulletins API from Chicago Transit Authority — 1 operation(s) for bulletins.
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Bulletins
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-bulletins-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-follow-api
  name: Chicago Transit Authority Follow API
  description: Follow an individual train run
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Follow
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-follow-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-locations-api
  name: Chicago Transit Authority Locations API
  description: Train geolocation operations
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Locations
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-locations-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-predictions-api
  name: Chicago Transit Authority Predictions API
  description: The Predictions API from Chicago Transit Authority — 1 operation(s) for predictions.
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Predictions
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-predictions-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-routes-api
  name: Chicago Transit Authority Routes API
  description: The Routes API from Chicago Transit Authority — 3 operation(s) for routes.
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Routes
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-routes-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-stops-api
  name: Chicago Transit Authority Stops API
  description: The Stops API from Chicago Transit Authority — 1 operation(s) for stops.
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Stops
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-stops-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-system-api
  name: Chicago Transit Authority System API
  description: The System API from Chicago Transit Authority — 1 operation(s) for system.
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - System
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-system-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
- aid: chicago-transit-authority:chicago-transit-authority-vehicles-api
  name: Chicago Transit Authority Vehicles API
  description: The Vehicles API from Chicago Transit Authority — 1 operation(s) for vehicles.
  humanURL: https://www.transitchicago.com/developers/traintracker/
  baseURL: http://lapi.transitchicago.com/api/1.0
  tags:
  - Vehicles
  properties:
  - type: OpenAPI
    url: openapi/chicago-transit-authority-vehicles-api-openapi.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/traintracker/
  - type: APIDocs
    url: https://www.transitchicago.com/developers/ttdocs/
  - type: APIKeyApplication
    url: https://www.transitchicago.com/developers/traintrackerapply/
  - type: TermsOfService
    url: https://www.transitchicago.com/developers/terms/
  - type: Spectral
    url: spectral/chicago-transit-authority-spectral.yml
  - type: Documentation
    url: https://www.transitchicago.com/developers/bustracker/
common:
- type: AgenticAccess
  url: agentic-access/chicago-transit-authority-agentic-access.yml
- type: DomainSecurity
  url: security/chicago-transit-authority-domain-security.yml
- type: Authentication
  url: authentication/chicago-transit-authority-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/chicago-transit-authority
- type: Website
  url: https://www.transitchicago.com/
- type: Portal
  name: CTA Developer Center
  url: https://www.transitchicago.com/developers/
- type: TermsOfService
  url: https://www.transitchicago.com/developers/terms/
- type: PrivacyPolicy
  url: https://www.transitchicago.com/privacy/
- type: APIKeyApplication
  url: https://www.transitchicago.com/developers/traintrackerapply/
- type: ChicagoDataPortal
  url: https://data.cityofchicago.org
- type: SystemMap
  url: https://www.transitchicago.com/maps/
- type: Newsroom
  url: https://www.transitchicago.com/news/
- type: ContactUs
  url: https://www.transitchicago.com/contactus/
- type: JSONLD
  url: json-ld/chicago-transit-authority-context.jsonld
- type: Spectral
  url: spectral/chicago-transit-authority-spectral.yml
- name: Features
  type: Features
  data:
  - name: Real-Time Train Arrivals
  - name: Real-Time Bus Arrivals
  - name: Train Run Locations
  - name: Bus Vehicle Locations
  - name: Route and Stop Directories
  - name: Customer Alerts and Service Status
  - name: Planned Outage Notifications
  - name: GTFS Static Schedule Feed
  - name: API Key Issuance
  - name: Open Chicago Transit Data
- name: UseCases
  type: UseCases
  data:
  - name: Rider-Facing Mobile Apps
  - name: Trip Planners and Routing
  - name: Real-Time Arrival Displays
  - name: Service Disruption Notifications
  - name: Schedule Visualizations
  - name: Accessibility Tooling
  - name: Smart City Dashboards
  - name: Multimodal Transit Apps
  - name: Research and Open Data Analysis
- name: Standards
  type: Standards
  data:
  - name: GTFS
  - name: GTFS-Realtime (consumed via partners)
  - name: REST
  - name: JSON
  - name: XML
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com