---
name: swarm
description: "Fan out N parallel workers, drain them, and return one report. Use for /swarm, 'swarm this', or parallel coverage, races, gauntlets, and exploration."
---

# Swarm

On Codex, read the [platform mapping](../poteto-mode/references/codex-tools.md), including its per-skill notes, before following this skill.

Fan out N parallel workers. They may cover separate slices, race the same brief, or mix both. The parent waits, aggregates, and returns one report.

## Start

Open a todolist with one entry per phase before launching anything.

1. Frame
2. Fan out
3. Aggregate
4. Report

## Phase A: Frame

1. State the done predicate and the artifact or report the swarm must return.
2. Choose the shape. Partition into slices, race N workers on identical briefs, or mix both. For a race or mixed shape, declare `first pass`, `rank all`, or `best-of` before spawning.
3. Set N from the user or derive it from the shape. N is total workers, not the number that run at once.
4. Pick the worker model from the `swarm workers` row in your harness's override sheet (see `setup-pstack`) when present. Otherwise use that role's first name for your harness in `plugins/pstack/models.json`; see [Models](#models). For a model race, name each arm's model up front.
5. Give each worker its own writable output when it writes.

## Phase B: Fan out

Spawn all N workers in one message with `subagent_type: "general-purpose"`, `run_in_background: true`, and the configured model. Claude Code subagents all run on this machine, so isolation comes from the worktree or output directory assigned in Phase A, not from a remote environment.

When a worker must start from a non-default branch, check that branch out in the worker's own worktree and name the worktree path in its brief.

Every brief stands alone. Include the goal, scope, exact slice or race arm, how to verify, and what to report. Reports use `PASS`, `ISSUES`, or `BLOCKED` with evidence.

If a worker drops out, proceed with N-1 and note it.

## Phase C: Aggregate

Read the terminal results. For coverage, every required slice needs a result. For a race, apply the selection rule declared up front. Use first pass, rank all, or best-of. Do not paste raw worker dumps.

Keep a compact result table, one-line evidenced issues, and explicit gaps or dropouts.

## Phase D: Report

Return one consolidated in-chat report with the table, issue one-liners, gaps or dropouts, and the race rule when used.

## Models

Role picks live in the plugin's `models.json`, two directories up from this
skill's own directory (`plugins/pstack/models.json` in the repo). Resolve it
from that directory, not from your working directory. See the Models section
of `poteto-mode` for how each harness learns that path. The file is keyed by
role and then by harness (`claude`, `codex`, `copilot`), each value an
ordered preference list. A spawner reads the entry for its own harness and
pins the first name in it. A row for the same role in your own harness's
override sheet (`~/.claude/pstack-models.md` on Claude Code,
`~/.codex/pstack-models.md` on Codex) wins over it; the sheet's path is its
harness key, so it can only override that harness. See `setup-pstack` to
write one. A role with no override row and no entry for your harness spawns
unpinned: the `Agent` call omits `model` and the child inherits yours.