openapi: 3.1.0 info: title: CTA Bus Tracker Arrivals Vehicles API description: The Chicago Transit Authority Bus Tracker API provides real-time bus arrival predictions, vehicle locations, route patterns, route lists, and stop directories for the CTA bus network. Access requires an API key issued by the CTA Developer Center. version: 2.0.0 contact: name: CTA Developer Center url: https://www.transitchicago.com/developers/ license: name: CTA Developer License Agreement url: https://www.transitchicago.com/developers/terms/ servers: - url: http://www.ctabustracker.com/bustime/api/v2 description: CTA Bus Tracker v2 production security: - apiKey: [] tags: - name: Vehicles paths: /getvehicles: get: operationId: getVehicles summary: Get Vehicles description: Returns vehicle positions for routes or specific vehicles. tags: - Vehicles parameters: - $ref: '#/components/parameters/key' - name: vid in: query description: Comma-separated vehicle IDs. schema: type: string - name: rt in: query description: Comma-separated route designators. schema: type: string - $ref: '#/components/parameters/format' responses: '200': description: Vehicle positions components: parameters: format: name: format in: query description: Response format (xml or json). Defaults to XML. schema: type: string enum: - xml - json key: name: key in: query required: true description: CTA Bus Tracker API key. schema: type: string securitySchemes: apiKey: type: apiKey in: query name: key