Why is the contextId is not part of TaskIdParams request?

[irshadnilam]

Hello A2A Team,

First, thank you for the excellent and detailed work on the A2A protocol specification.

As I'm planning some implementation, I have a question regarding the design of the tasks/get method. I noticed that it retrieves a task using only the taskId as a unique identifier.

From a server-side perspective, I'm envisioning a hierarchical data model where tasks are naturally scoped within a session or conversation, which corresponds to the contextId. The logical structure would be something like:

Session (identified by contextId) -> contains multiple -> Tasks (each with a taskId)

In this kind of architecture, it would be more direct and potentially more performant to locate a specific task by providing both the contextId and the taskId.

The current design, which relies on a globally unique taskId, seems to imply that the server must maintain a separate, global index or Task Manager to map a taskId back to its parent context. This adds a bit of implementation complexity and a potential extra lookup step.

Please correct me if my thinking is wrong.