multi-agent

Working with other agents

Three mechanisms, and they are not interchangeable. Pick by what you need back, not by how big the job feels.

	task	delegate	a second CLI in tmux
Runs in	your process	its own process, headless	its own terminal
You get back	the subagent's answer	the worker's final answer	messages, when it sends them
Can write files	no, read-only	yes	yes
Parallel	yes — several in one message	yes, a few at once	start several sessions
Human can watch or join	no	no	yes, attach to the pane
Outlives you	no	no	yes, until killed
Cost	cheap aux model each	a whole session each	a whole session each

• task for reading and reporting: explore, research, review. Cheapest, and the default way to run workers in parallel — issue several task calls in one message. Parallelism is not a reason to reach for delegate or a second CLI.
• delegate for a self-contained job you want the answer to. It is a full session with its own context window, tracked like a background process.
• A second CLI when the work needs a place a human can look at and take over: a long second workstream, a different repo or worktree, a job the user wants to supervise. This is the only one that survives you.

Do not reach for the second CLI when task or delegate would do. It is the most expensive option and the only one that leaves something running.

This session moving itself into a checkout of the same repo is the worktree skill (the worktree tool), not a second process.

Starting a second CLI

Requires tmux (command -v tmux). Everything below is one execute call.

tmux new-session -d -s docs-worker -c ~/code/myrepo-docs agentica

Then confirm it came up with list_agents - it publishes itself within a couple of seconds.

Four things decide whether this goes well:

1. The directory is the name. A session's addressable name comes from its working directory, so -c ~/code/myrepo-docs is what makes it show up as myrepo-docs-4f instead of something unreadable. There is no flag to name a session. Choose the directory for the name you want.
2. Give it its own directory. A CLI started this way runs with tools enabled and nobody there to approve anything. Point it at a git worktree or a separate checkout unless you specifically intend two agents editing the same files.
3. Choose the worker's model with a profile, not a model name. --profile <name> runs that session on a saved profile - provider, endpoint and key together - and writes nothing, so the user's own session is unaffected. --model_name X only moves the model within the current endpoint, so it cannot reach another provider. Profile names come from ~/.agentica/config.yaml; a name that does not exist stops the worker immediately rather than silently falling back.
4. Tell the user it exists. Give them the attach command - tmux attach -t docs-worker, detach with Ctrl+B D. A worker nobody knows about is a worker nobody can rescue.