Overview

In this article we'll go over the basics you need to know on how to consume the Tasklist GraphQL API. To read more about on how to build a real world application you can click here.

Endpoint

Tasklist provides a GraphQL API at endpoint /graphql.

Authentication

To access the API endpoint, you need an access token.

Your client must send a header in each request:

Authorization: Bearer <Token>

For example, send a request 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 must obtain a token to use the Tasklist API. When you create a Tasklist client, you get all the information needed to connect to Tasklist.

See our guide on building your own client.

The 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 following content:

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

See the following 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"
}

Obtaining the Tasklist schema

To obtain the Tasklist GraphQL schema, send a request to the endpoint with a GraphQL introspection query as described here, or use the generated API documentation.

There are also several tools to explore GraphQL APIs here.

For example, you want to know about provided types:

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

Example requests and responses

Get all tasks names

Request:

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

Response:

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

Get all tasks completed with id, name, and state

Request:

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

Response:

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