API Client

Endpoint

Tasklist provides an GraphQL API at endpoint /graphql.

Authentication

To access the API endpoint you need an access token. Your client needs to send a header in each request:

Authorization: Bearer <Token>

For example send a request by using curl:

curl -X POST -H "Content-Type: application/json" -H "Authorization: Bearer <TOKEN>" -d '{"query": "{tasks(query:{}){name}}"}' http://localhost:8080/graphql

How to obtain the access token

You need to obtain a token for using the Tasklist API. When you create a Tasklist client you will get all the information you need to connect to Tasklist.

See also Build your own client

Following settings are needed:

Name	Description	Default value
client id	Name of your registered client	-
client secret	Password for your registered client	-
audience	Permission name, if not given use default value	tasklist.camunda.io
authorization server url	Token issuer server	-

You send a token issue POST request to the authorization server with the content:

{
  "client_id": "<client-id>",
  "client_secret":"<client-secret>",
  "audience":"<audience>",
  "grant_type":"client_credentials"
}

An example with curl:

curl -X POST --header 'content-type: application/json' --data '{"client_id": "<client-id>", "client_secret":"<client-secret>","audience":"<audience>","grant_type":"client_credentials"}' https://<authorization server url>

If the authorization is successful, the authorization server sends back the access token, when it expires, scope and type:

{
  "access_token": "ey...",
  "scope": "...",
  "expires_in": 86400,
  "token_type": "Bearer"
}

Obtain GraphQL Schema

To obtain the GraphQL schema you need to send a request to the endpoint with a GraphQL introspection query as described in https://graphql.org/learn/introspection/

or you use the generated API documentation

There are also a lot of tools to explore GraphQL API's like this: https://altair.sirmuel.design

For example you want to know all about provided types:

query {
  __schema {
    queryType {
      fields {
        name
        type {
          kind
          ofType {
            kind
            name
          }
        }
      }
    }
  }
}

Examples requests and responses

Get all tasks names

Request:

{"query":"{
    tasks(query: {}) {
        name
    }
  }"
}

Response:

{
  "data": {
    "tasks": [
      {
        "name": "Check payment"
      },
      {
        "name": "Register the passenger"
      }
    ]
  }
}

Get all tasks that are completed with id, name and state

Request:

{
    "query" : "{
        tasks(query: { state: COMPLETED }) {
            id
            name
            taskState
        }
    }"
}

Response:

{
  "data": {
    "tasks": [
      {
        "id": "2251799813685728",
        "name": "Check payment",
        "taskState": "COMPLETED"
      }
    ]
  }
}