asana api: data block in create task endpoint

I have 2 questions regarding creating tasks using the asana api:

(https://asana.com/developers/api-reference/tasks)

1. From the documentation it seems you only specify the workspace to create the task and not the project:

POST /workspaces/workspace-id/tasks/{data}

If so the following would not work?

POST /projects/project-id/tasks/{data}

2. Is there a limit to the amount of data which be added in the data block?

In the example in the api documentation the following data is used:

# Request
curl -u <api_key>: https://app.asana.com/api/1.0/tasks \
-d "assignee=1235" \
-d "followers[0]=5678" \
-d "name=Hello, world%21" \
-d "notes=How are you today%3F" \
-d "workspace=14916"

Can I add attachments, stories, tags, hearts etc. to the data block? Or does this have to done with update task endpoint?

Solution

In the description of each resource, e.g. the Task, the documentation shows the set of properties that are available on that resource during creation and update. It also shows which of them are read-only which means that you cannot modify them through the creation or update endpoint.

For example, tasks have a hearts property, but that property is read-only. You cannot currently add hearts via the REST API, though that's on our roadmap.

Tasks do not have a stories property, so you cannot set those through the POST/PUT endpoint either. However, you can add a story to a task by POSTing to /tasks/:taskid/stories. Many associations between objects behave this way.