It isn't sub agents. The gap with existing tooling is that the abstraction is over a task rather than a conversation (due to the issue with third-party apps, Claude Code has been inherently limited to conversations which is why they have been lacking in this area, Claude Code Web was the first move in this direction), and the AI is actually coordinating the work (as opposed to being constantly prompted by the user).

One of the issues that people had which necessitated this feature is that you have a task, you tell Claude to work on it, and Claude has to keep checking back in for various (usually trivial) things. This workflow allows for more effective independent work without context management issues (if you have subagents, there is also an issue with how the progress of the task is communicated by introducing things like task board, it is possible to manage this state outside of context). The flow is quite complex and requires a lot of additional context that isn't required with chat-based flow, but is a much better way to do things.

The way to think about this pattern - one which many people began concurrently building in the past few months - is an AI which manages other AIs.

It’s even less of a feature, Claude Code already has subagents; this new feature just ensures Claude Code actually uses this for implementation.

imho the plans of Claude Code are not detailed enough to pull this off; they’re trying to do it to preserve context, but the level of detail in the plans is not nearly enough for it to be reliable.

OT: Your visual on "stacked PRs" instantly made me understand what a stacked PR is. Thank you!

I had read about them before but for whatever reason it never clicked.

Turns out I already work like this, but I use commits as "PRs in the stack" and I constantly try to keep them up to date and ordered by rebasing, which is a pain.

Given my new insight with the way you displayed it, I had a chat with chatGPT and feel good about giving it a try:

    1. 2-3 branches based on a main feature branch
    2. can rebase base branch with same frequency, just don't overdo it, conflicts should be base-isolated.
    3. You're doing it wrong if conflicts cascade deeply and often
    4. Yes merge order matters, but tools can help and generally the isolation is the important piece

Claude already had subagents. This is a new mode for the main agent to be in (bespoke context oriented to delegation), combined with a team-oriented task system and a mailbox system for subagents to communicate with each other. All integrated into the harness in a way that plugins can't achieve.

Yeah, since they introduced (possibly async) subagents, I've had my main claude instance act as a manager overseeing implementation agents, keeping it's context clean, and ensuring everything goes to plan in the highest quality way.

Any recommendations on sandboxing agents? Last time I asked folks recommended docker.