ctaql is an experiment with GraphQL to provide access to the CTA Bus Tracker API. Graphene-Django is used to define a schema that describes the data and implement the query logic to retrieve the bustracker data.

see it in action at https://ctaql.rockst4r.net

example queries

get list of all bus routes

{
  routes {
    name
    number
  }
}

output

{
  "data": {
    "routes": [
      {
        "name": "Bronzeville/Union Station",
        "number": "1"
      },
      ...
      {
        "name": "Evanston Circulator",
        "number": "206"
      }
    ]
  }
}

get stops for a bus route

{
  route(number:"92") {
    number
    name
    stops {
      number
      name
      direction
      latitude
      longitude
    }
  }
}

output

{
  "data": {
    "route": {
      "number": "92",
      "name": "Foster",
      "stops": [
        {
          "number": "4766",
          "name": "3700 W Foster",
          "direction": "Eastbound",
          "latitude": 41.975472,
          "longitude": -87.721260000001
        },
        ...
        {
          "number": "1041",
          "name": "Sheridan & Berwyn ",
          "direction": "Westbound",
          "latitude": 41.977888,
          "longitude": -87.655092
        }
      ]
    }
  }
}

get arrival times for a stop

{
  arrivals(stop:"1926") {
    route {
      number
      name
    }
    vehicle {
      number
      destination
    }
    direction
    time
  }
}

output

{
  "data": {
    "arrivals": [
      {
        "route": {
          "number": "22",
          "name": "Clark"
        },
        "vehicle": {
          "number": "1873",
          "destination": "Howard"
        },
        "direction": "Northbound",
        "time": "20201208 22:30"
      }
    ]
  }
}

get vehicles on a route

{
  route(number: "151") {
    vehicles {
      number
      destination
      heading
      latitude
      longitude
    }
  }
}

output

{
  "data": {
    "route": {
      "vehicles": [
        {
          "number": "4166",
          "destination": "Foster",
          "heading": 359,
          "latitude": 41.93389840853416,
          "longitude": -87.63931662349377
        },
        ...
        {
          "number": "4358",
          "destination": "Union Station",
          "heading": 280,
          "latitude": 41.87939778312308,
          "longitude": -87.6361819407979
        }
      ]
    }
  }
}

get predictions for a vehicle

{
  arrivals(vehicle: "1819") {
    stop {
      number
      name
    }
    direction
    time
  }
}

output

{
  "data": {
    "arrivals": [
      {
        "stop": {
          "number": "14176",
          "name": "Clark & Arthur Terminal"
        },
        "direction": "Southbound",
        "time": "20211109 20:48"
      },
      ...
      {
        "stop": {
          "number": "1039",
          "name": "Sheridan & Catalpa"
        },
        "direction": "Southbound",
        "time": "20211109 21:00"
      }
    ]
  }
}

run the code

clone the repository

git clone git@github.com:vicgarcia/ctaql.git
cd ctaql

copy the .env file from the example and add SECRET_KEY and CTA_BUSTRACKER_API_KEY

cp .env.example .env
vim .env

build + start the docker container

docker-compose build
docker-compose up

use the running GraphiQL UI at http://localhost:8000/graphql/