Description

User tasks with the implementation type: Job Implementation is not completing in Play.
More general scenario: User tasks cannot be completed through the Tasklist V1 API when authentication with an M2M client.

Steps to reproduce

1. Create a diagram with a user task
2. Selec Job Implementation as implementation type
3. Click on Play
4. Create an instance
5. Complete the user task.

Current behavior

There is this error showing up

{ "detail": "Unexpected error occurred: Response code 400 (Bad Request) (request to https://lpp-1.tasklist.dev.ultrawombat.com/f0412a10-1028-4a6c-aefb-7ed9401c440b/v1/tasks/2251799813703500/complete). {\"status\":400,\"message\":\"{ \\\"title\\\": \\\"TASK_NOT_ASSIGNED\\\",\\n \\\"detail\\\": \\\"Task is not assigned\\\"\\n}\\n\",\"instance\":\"65c76b15-4b88-43bd-a18e-cb3787c11f8b\"}" }

Expected behavior

A User task with the implementation type: Job Implementation can be completed in Play

Environment

SaaS

Version

• Component Version: [e.g. 2.0.0]

Rootcause

• When completing a task (and on other state changes), the Tasklist V1 API validates if the requesting user is the assignee of the task
  
  There is already some investigation happening here
• The corresponding check for an API user does currently not work with the consolidated-auth filter and the new security filter chain

Solution ideas

• See a first idea here: https://camunda.slack.com/archives/C08MRKHJ0CD/p1749055977775519?thread_ts=1749051346.556369&cid=C08MRKHJ0CD

Dev -> QA handover

• Resources:
• Versions to validate:
• Release version (in which version this feature will be released):

Links

• Problem was reported here: https://camunda.slack.com/archives/C08MRKHJ0CD/p1749052495005809?thread_ts=1749051346.556369&cid=C08MRKHJ0CD