### **Environment**:

Your OpenProject Version: 12.0

Operating System / Browser / OpenProject language: Linux/Chromium

### **Logs**

\-

### **Steps to reproduce:**

1. Look at the specs of the create\_relation call in the workpackages endpoint: https://www.openproject.org/docs/api/endpoints/work-packages/#create-relation

2. look at the call in the OpenAPI spec file: "/api/v3/work\_packages/{id}/relations" having really only the id as parameter


### **Actual Behavior**

The text says: "When calling this endpoint the client provides a single object, containing at least the properties and links that are required, in the body. ..." The API on the other hand does only allow to specify one id as argument. There is no body that can be sent.

### **Expected Behavior**

API should look like the addComment call in the workpackages endpoint. So I would guess it needs to look more like the API for /api/v3/work\_packages/{id}/activities . This has a requestBody section.

### Hint

* check for cross functionality with all endpoints under `/api/v3/relations` Begin of the insertion


### For QA

* check if relations endpoints are documented and rendered correctly e.g. at `/api/docs`

* relevant endpoints

* `/api/v3/relations` (all)

* `/api/v3/work_packages/:id/relations` (POST)End of the insertion