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tryn-api

API for historical transit vehicle location data.

tryn-api provides a GraphQL API for the data previously stored in S3 by Orion (https://github.com/trynmaps/orion).

Getting Started

See our welcome doc for contribution and deployment guidelines. https://bit.ly/opentransit-onboarding

  1. Clone this repo.

  2. Create a docker-compose.override.yml file that sets the environment variable TRYNAPI_S3_BUCKET to the name of the S3 bucket where data was stored by Orion, and provides AWS credentials with read access to that bucket. tryn-api reads data from S3 using the AWS credentials from the default locations, e.g. a credentials file located within the Docker container at /root/.aws/credentials (using the default profile or a profile named by AWS_PROFILE), or using the environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY. For example:

version: "3.7"
services:
  tryn-api-dev:
    volumes:
      - ../.aws:/root/.aws
    environment:
      AWS_PROFILE: "default"
      TRYNAPI_S3_BUCKET: "my-opentransit-bucket"
  1. Run docker-compose up

The GraphQL API will be available at http://localhost:4000/graphql .

API Documentation

Query

The root query object for the API.

Field Name Type Description
state [AgencyState] Returns historical state of vehicles for a particular transit agency.

Parameters for state

Parameter Name Type Description
agency String! ID of the agency. The agency ID should be the same ID used in the configuration for Orion.
startTime BigInt! Start timestamp in seconds since the Unix epoch.
endTime BigInt! End timestamp in seconds since the Unix epoch , exclusive.
routes [String!] List of route IDs to return vehicle data.

AgencyState

Field Name Type Description
agencyId String ID of the agency. The agency ID should be the same ID used in the configuration for Orion.
startTime BigInt Start timestamp in seconds since the Unix epoch.
endTime BigInt End timestamp in seconds since the Unix epoch, exclusive.
routes [RouteHistory] Array of historical state for each route.

RouteHistory

Field Name Type Description
routeId String ID of the route.
states [RouteState] Array of historical data for this route.

RouteState

State of a particular route at a particular time.

Field Name Type Description
timestamp BigInt Timestamp when vehicle data was retrieved, in seconds since the Unix epoch.
vehicles [VehicleState] Array of vehicles observed at this timestamp.

VehicleState

State of a particular vehicle at a particular time. Some fields may be null if not provided by the data source.

Field Name Type Description
vid String ID of this vehicle.
did String ID of the direction the vehicle reported it was going.
lat Float Reported latitude of vehicle.
lon Float Reported longitude of vehicle.
heading Float Reported heading of vehicle in degrees.
secsSinceReport Int Number of seconds old this observation was when it was retrieved (at timestamp of RouteState).
numCars Int Number of cars in this vehicle.
stopIndex Int The index of the current stop in the sequence (GTFS-realtime providers only)
status Int 0 if the vehicle is about to arrive at the stop referred to by stopIndex, 1 if the vehicle is stopped at this stop, 2 if the vehicle is in transit to this stop (GTFS-realtime providers only)
tripId String ID of the trip the vehicle reported it was running (GTFS-realtime providers only)

Sample Query

Once you run it, go to http://localhost:4000/graphql in your browser and run this query:

query {
  state(agencyId: "muni", startTime: 1572105600, endTime: 1572112800, routes: ["14", "19", "49"]) {
    agencyId
    startTime
    routes {
      routeId
      states {
        timestamp
        vehicles {
          vid
          lat
          lon
          heading
        }
      }
    }
  }
}

Substitute startTime and endTime with epoch timestamps (in seconds) corresponding to when Orion was actually running.

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OpenTransit API for historical transit vehicle location data

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