openapi: 3.0.3
info:
  title: Transit API
  description: >-
    The Transit API delivers real-time public transit data - nearby routes and
    stops, stop departures, route details, multimodal trip planning, and service
    alerts - across 1,100+ cities in 37 countries, plus shared-mobility
    availability for bikes, scooters, and carshare. The API is publicly
    documented at https://api-doc.transitapp.com/ but access is key-gated:
    developers request an access key (free tier of 5 requests/minute and 1,500
    requests/month) via Transit's request form, and higher volumes are arranged
    with the partnerships team.


    Requests are made against https://external.transitapp.com/v3 and
    authenticated with an `apiKey` request header. An `Accept-Language` header
    selects the response language.


    Grounding note: the `apiKey` header, the `https://external.transitapp.com/v3`
    base URL, and the `GET /public/nearby_stops` endpoint (with `lat`, `lon`,
    and `max_distance` parameters) are confirmed from Transit's public
    documentation and working integrations. The remaining endpoints
    (`nearby_routes`, `stop_departures`, `route_details`, `otp/plan`,
    `service_alerts`, `available_networks`) and their request/response shapes
    are modeled honestly from Transit's documented v3 API surface, GTFS /
    GTFS-realtime conventions, and Transit's public capability descriptions;
    they are marked with `x-modeled: true`. Confirm exact field names against
    the live docs once an access key is issued.
  version: '3.0'
  contact:
    name: Transit Partnerships
    url: https://transitapp.com/partners/apis
    email: partners@transit.app
  x-logo:
    url: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
servers:
  - url: https://external.transitapp.com/v3
    description: Transit public API v3
security:
  - apiKeyAuth: []
tags:
  - name: Nearby Routes
    description: Public transit routes near a location with real-time departures.
  - name: Nearby Stops
    description: Public transit stops near a location.
  - name: Stop Departures
    description: Upcoming departures for a specific stop.
  - name: Route Details
    description: Itineraries, stops, and geometry for a specific route.
  - name: Trip Planning
    description: Multimodal origin-to-destination trip planning.
  - name: Service Alerts
    description: Service alerts and disruptions for routes, stops, and networks.
  - name: Locations
    description: Available transit networks and coverage near a location.
paths:
  /public/nearby_routes:
    get:
      operationId: getNearbyRoutes
      tags:
        - Nearby Routes
      summary: Get nearby routes
      description: >-
        Returns the public transit routes near a latitude/longitude, each with
        upcoming real-time departures, direction and headsign, wheelchair
        accessibility, and network branding.
      x-modeled: true
      parameters:
        - name: lat
          in: query
          required: true
          description: Latitude of the search center (WGS84 decimal degrees).
          schema:
            type: number
            format: double
            example: 45.5088
        - name: lon
          in: query
          required: true
          description: Longitude of the search center (WGS84 decimal degrees).
          schema:
            type: number
            format: double
            example: -73.5878
        - name: max_distance
          in: query
          required: false
          description: Maximum search radius in meters.
          schema:
            type: integer
            default: 500
            example: 500
        - name: should_update_realtime
          in: query
          required: false
          description: When true, include live real-time departure predictions.
          schema:
            type: boolean
            default: true
        - name: Accept-Language
          in: header
          required: false
          description: Preferred response language (BCP 47), e.g. en, fr, es.
          schema:
            type: string
            example: en
      responses:
        '200':
          description: A list of nearby routes with departures.
          content:
            application/json:
              schema:
                type: object
                properties:
                  routes:
                    type: array
                    items:
                      $ref: '#/components/schemas/Route'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /public/nearby_stops:
    get:
      operationId: getNearbyStops
      tags:
        - Nearby Stops
      summary: Get nearby stops
      description: >-
        Returns the transit stops near a latitude/longitude within a maximum
        distance, each with a stable global_stop_id and the routes that serve
        it. Confirmed endpoint.
      x-modeled: false
      parameters:
        - name: lat
          in: query
          required: true
          description: Latitude of the search center (WGS84 decimal degrees).
          schema:
            type: number
            format: double
            example: 45.5088
        - name: lon
          in: query
          required: true
          description: Longitude of the search center (WGS84 decimal degrees).
          schema:
            type: number
            format: double
            example: -73.5878
        - name: max_distance
          in: query
          required: false
          description: Maximum search radius in meters.
          schema:
            type: integer
            default: 150
            example: 150
        - name: Accept-Language
          in: header
          required: false
          description: Preferred response language (BCP 47).
          schema:
            type: string
            example: en
      responses:
        '200':
          description: A list of nearby stops.
          content:
            application/json:
              schema:
                type: object
                properties:
                  stops:
                    type: array
                    items:
                      $ref: '#/components/schemas/Stop'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /public/stop_departures:
    get:
      operationId: getStopDepartures
      tags:
        - Stop Departures
      summary: Get stop departures
      description: >-
        Returns the upcoming departures for a specific stop identified by its
        global_stop_id, grouped by route and direction, blending real-time
        predictions with scheduled times.
      x-modeled: true
      parameters:
        - name: global_stop_id
          in: query
          required: true
          description: The stable global stop identifier returned by nearby_stops.
          schema:
            type: string
            example: 'BMTC:stop:12345'
        - name: should_update_realtime
          in: query
          required: false
          description: When true, include live real-time predictions.
          schema:
            type: boolean
            default: true
        - name: Accept-Language
          in: header
          required: false
          description: Preferred response language (BCP 47).
          schema:
            type: string
            example: en
      responses:
        '200':
          description: Upcoming departures for the stop.
          content:
            application/json:
              schema:
                type: object
                properties:
                  route_departures:
                    type: array
                    items:
                      $ref: '#/components/schemas/RouteDepartures'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /public/route_details:
    get:
      operationId: getRouteDetails
      tags:
        - Route Details
      summary: Get route details
      description: >-
        Returns the detail for a specific route identified by its
        global_route_id - its itineraries/directions, the ordered list of stops,
        path geometry, and branding.
      x-modeled: true
      parameters:
        - name: global_route_id
          in: query
          required: true
          description: The stable global route identifier.
          schema:
            type: string
            example: 'STM:route:747'
        - name: Accept-Language
          in: header
          required: false
          description: Preferred response language (BCP 47).
          schema:
            type: string
            example: en
      responses:
        '200':
          description: Route detail with itineraries, stops, and geometry.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/RouteDetail'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /otp/plan:
    get:
      operationId: planTrip
      tags:
        - Trip Planning
      summary: Plan a multimodal trip
      description: >-
        Multimodal trip planning between an origin and a destination, returning
        ranked itineraries that combine public transit with walking, biking, and
        shared mobility. Built on an OpenTripPlanner-style plan surface.
      x-modeled: true
      parameters:
        - name: fromPlace
          in: query
          required: true
          description: Origin as "lat,lon".
          schema:
            type: string
            example: '45.5088,-73.5878'
        - name: toPlace
          in: query
          required: true
          description: Destination as "lat,lon".
          schema:
            type: string
            example: '45.4972,-73.5793'
        - name: date
          in: query
          required: false
          description: Travel date (YYYY-MM-DD). Defaults to today.
          schema:
            type: string
            format: date
        - name: time
          in: query
          required: false
          description: Travel time (HH:MM). Defaults to now.
          schema:
            type: string
        - name: arriveBy
          in: query
          required: false
          description: When true, treat date/time as the desired arrival time.
          schema:
            type: boolean
            default: false
        - name: mode
          in: query
          required: false
          description: Comma-separated modes, e.g. TRANSIT,WALK,BICYCLE.
          schema:
            type: string
            example: 'TRANSIT,WALK'
        - name: Accept-Language
          in: header
          required: false
          description: Preferred response language (BCP 47).
          schema:
            type: string
            example: en
      responses:
        '200':
          description: Ranked trip itineraries.
          content:
            application/json:
              schema:
                type: object
                properties:
                  plan:
                    type: object
                    properties:
                      itineraries:
                        type: array
                        items:
                          $ref: '#/components/schemas/Itinerary'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /public/service_alerts:
    get:
      operationId: getServiceAlerts
      tags:
        - Service Alerts
      summary: Get service alerts
      description: >-
        Returns service alerts and disruptions - delays, detours, elevator
        outages, and cancellations - scoped to a route, stop, or network,
        following the GTFS-realtime service-alert model.
      x-modeled: true
      parameters:
        - name: global_route_id
          in: query
          required: false
          description: Filter alerts affecting a specific route.
          schema:
            type: string
        - name: global_stop_id
          in: query
          required: false
          description: Filter alerts affecting a specific stop.
          schema:
            type: string
        - name: network_id
          in: query
          required: false
          description: Filter alerts affecting a specific transit network/agency.
          schema:
            type: string
        - name: Accept-Language
          in: header
          required: false
          description: Preferred response language (BCP 47).
          schema:
            type: string
            example: en
      responses:
        '200':
          description: Matching service alerts.
          content:
            application/json:
              schema:
                type: object
                properties:
                  alerts:
                    type: array
                    items:
                      $ref: '#/components/schemas/ServiceAlert'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /public/available_networks:
    get:
      operationId: getAvailableNetworks
      tags:
        - Locations
      summary: Get available networks near a location
      description: >-
        Discovers the transit networks and coverage available near a
        latitude/longitude - the agencies and systems Transit has data for in
        that location.
      x-modeled: true
      parameters:
        - name: lat
          in: query
          required: true
          description: Latitude of the search center (WGS84 decimal degrees).
          schema:
            type: number
            format: double
            example: 45.5088
        - name: lon
          in: query
          required: true
          description: Longitude of the search center (WGS84 decimal degrees).
          schema:
            type: number
            format: double
            example: -73.5878
        - name: Accept-Language
          in: header
          required: false
          description: Preferred response language (BCP 47).
          schema:
            type: string
            example: en
      responses:
        '200':
          description: Available transit networks near the location.
          content:
            application/json:
              schema:
                type: object
                properties:
                  networks:
                    type: array
                    items:
                      $ref: '#/components/schemas/Network'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
components:
  securitySchemes:
    apiKeyAuth:
      type: apiKey
      in: header
      name: apiKey
      description: >-
        Transit access key requested via Transit's API request form. Sent as the
        `apiKey` request header on every call.
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    RateLimited:
      description: Rate limit exceeded (free tier is 5 requests/minute, 1,500/month).
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    Network:
      type: object
      properties:
        network_id:
          type: string
          example: 'STM'
        network_name:
          type: string
          example: 'Société de transport de Montréal'
        location_name:
          type: string
          example: 'Montreal'
    Route:
      type: object
      properties:
        global_route_id:
          type: string
          example: 'STM:route:747'
        route_short_name:
          type: string
          example: '747'
        route_long_name:
          type: string
          example: 'YUL Aéroport - Centre-ville'
        route_color:
          type: string
          example: '009EE0'
        route_text_color:
          type: string
          example: 'FFFFFF'
        mode_name:
          type: string
          example: 'bus'
        itineraries:
          type: array
          items:
            $ref: '#/components/schemas/Itinerary'
    Stop:
      type: object
      properties:
        global_stop_id:
          type: string
          example: 'STM:stop:12345'
        stop_name:
          type: string
          example: 'Berri-UQAM'
        stop_lat:
          type: number
          format: double
          example: 45.5152
        stop_lon:
          type: number
          format: double
          example: -73.5615
        distance:
          type: integer
          description: Distance from the search center in meters.
          example: 87
        wheelchair_boarding:
          type: boolean
          example: true
        route_type:
          type: integer
          description: GTFS route_type served at this stop.
          example: 1
    RouteDepartures:
      type: object
      properties:
        global_route_id:
          type: string
          example: 'STM:route:747'
        route_short_name:
          type: string
          example: '747'
        direction_headsign:
          type: string
          example: 'Centre-ville'
        departures:
          type: array
          items:
            $ref: '#/components/schemas/Departure'
    Departure:
      type: object
      properties:
        departure_time:
          type: integer
          description: Unix epoch seconds of the departure.
          example: 1751558400
        is_real_time:
          type: boolean
          example: true
        is_cancelled:
          type: boolean
          example: false
        headsign:
          type: string
          example: 'Centre-ville'
    RouteDetail:
      type: object
      properties:
        global_route_id:
          type: string
          example: 'STM:route:747'
        route_short_name:
          type: string
          example: '747'
        route_long_name:
          type: string
          example: 'YUL Aéroport - Centre-ville'
        itineraries:
          type: array
          items:
            $ref: '#/components/schemas/ItineraryDetail'
    ItineraryDetail:
      type: object
      properties:
        direction_id:
          type: integer
          example: 0
        headsign:
          type: string
          example: 'Centre-ville'
        stops:
          type: array
          items:
            $ref: '#/components/schemas/Stop'
        shape:
          type: string
          description: Encoded polyline of the route path geometry.
    Itinerary:
      type: object
      properties:
        duration:
          type: integer
          description: Total trip duration in seconds.
          example: 1980
        start_time:
          type: integer
          description: Unix epoch seconds of departure.
        end_time:
          type: integer
          description: Unix epoch seconds of arrival.
        legs:
          type: array
          items:
            $ref: '#/components/schemas/Leg'
    Leg:
      type: object
      properties:
        mode:
          type: string
          example: 'BUS'
        from:
          type: string
          example: 'YUL Aéroport'
        to:
          type: string
          example: 'Centre-ville'
        route_short_name:
          type: string
          example: '747'
        duration:
          type: integer
          example: 1500
    ServiceAlert:
      type: object
      properties:
        alert_id:
          type: string
          example: 'stm-2026-0701-747'
        cause:
          type: string
          description: GTFS-realtime alert cause.
          example: 'CONSTRUCTION'
        effect:
          type: string
          description: GTFS-realtime alert effect.
          example: 'DETOUR'
        header_text:
          type: string
          example: 'Route 747 detour'
        description_text:
          type: string
          example: 'The 747 is detoured due to construction on René-Lévesque.'
        severity:
          type: string
          example: 'WARNING'
        active_period_start:
          type: integer
          description: Unix epoch seconds the alert becomes active.
        active_period_end:
          type: integer
          description: Unix epoch seconds the alert ends.
        affected_global_route_ids:
          type: array
          items:
            type: string
    Error:
      type: object
      properties:
        status:
          type: integer
          example: 401
        message:
          type: string
          example: 'Invalid API key.'