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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Chicago Transit Authority the way a machine reads it — 39 machine-readable artifacts across 11 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Chicago Transit Authority scores 46.7/100 (developing), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Chicago Transit Authority
Each block below is one kind of artifact we hold for Chicago Transit Authority. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 11
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
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.
Scroll within the panel for all 11 ·
Open Collections 2
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
CTA Bus Tracker API
OPEN COLLECTIONCTA Train Tracker API
OPEN COLLECTIONPricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Chicago Transit Authority Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Features 10
The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.
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 within the panel for all 10 ·
Semantic Vocabularies 1
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Security Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Use Cases 9
What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.
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 within the panel for all 9 ·
Resources
Every other property we hold for Chicago Transit Authority — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 2
Portal, sign-up, and the first successful call
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 2
Pagination, idempotency, versioning, errors, and events
Access & Security 3
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 2
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/chicago-transit-authority · machine-readable index on apis.io