Work with subagents

Have a Session hand work to subagents, then follow, message, stop and resume them from the web UI. Everyone in the Session follows them. Messaging, stopping and resuming are the Session’s Creator’s.

What you need

• A Session: see Work in a Session.

Ask for subagents

Claude starts subagents with Claude Code’s Agent tool. Ask for them in a prompt:

Use a background agent to write the changelog, and another, in a worktree, to update the API docs.

• In the background, the default, an agent keeps running after the Turn ends. When it’s done, Claude Code starts a Turn to read its result.
• In the foreground, the Turn waits for the agent.
• In a worktree, the agent works in its own checkout, on its own branch.

Every agent shares the Session’s Sandbox. If they need more CPU or memory, raise the Environment’s resources.

Follow an agent

Each agent is a card in the transcript that streams its work. In the sidebar, the Session’s agents are listed under its row, each with a status:

Status	Meaning
Running	The agent is working.
Done	The agent finished.
Stopped	The Creator, or Claude, stopped it.
Interrupted	The Session’s Claude Code stopped while the agent ran.

To open an agent’s view, click its row in the sidebar, or Message or stop it on its card. Back to the chat returns to the transcript.

Message, stop or resume an agent

In the agent’s view:

1. To message a running agent, type in the box and press Send message. The agent reads it, with your name, at its next tool call.

2. To stop it, press Stop agent. Claude Code starts a Turn to tell the Session’s Claude.

3. To resume an agent that is Done, Stopped or Interrupted, type what it should do and press Resume. It picks up where it left off. A message to an agent of an Asleep Session wakes the Session first.

Stop on a Turn doesn’t stop a background agent. Stop it from its view.

After sleep or a restart

Agents run inside the Session’s Claude Code, so they stop when it does: when the Session sleeps, when its model or Environment changes, or when its Runner is lost. While agents run, Sleep now and a restart ask first, and the Session doesn’t fall asleep on its own.

Agents that were running show as Interrupted. Their work so far is kept: resume one to carry on.

Merge a worktree agent’s work

A worktree agent works on the branch worktree-agent-<agent id>, shown on its card. To bring its work onto the Session’s Work branch, ask:

Merge the worktree agent's branch into this branch.

Until then the branch is local to the Session. It reaches GitHub only if the Session pushes it.

Next steps

Manage a SessionSleep, wake and model changes, which interrupt agents.

Set up an EnvironmentGive agents more CPUs and memory.