Swarm

---
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

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.

**Dispatch contract.** Resolve each worker descriptor through [`provider-dispatch.md`](../poteto-mode/references/provider-dispatch.md). The parent starts native and external lanes; workers never route themselves. On Codex, resolve remaining Claude tool names via [`codex-tools.md`](../poteto-mode/references/codex-tools.md).

## 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 descriptor from the `swarm workers` line in the current harness's pstack model sheet. If the sheet or that line is missing, use `grok:grok-4.7@xhigh`. For `auto` or `inherit-parent`, the workers run on the parent model through its native lane. Each worker seat follows provider-dispatch's saved-chain policy before every attempt. A terminal outcome the sheet's `# fallback` policy authorizes makes a read-only worker eligible for its next saved attempt (`usage-exhausted` only when no policy is saved); a writer advances only when the helper proves the workload never started or a recorded parent inspection clears it, and otherwise stops for inspection. Every other route failure is a dropout, not a substitution. For a model race, name each arm's descriptor up front.
5. Give each worker its own writable output when it writes. When workers verify or measure commits, each brief names the exact SHAs. A measurement brief also names the method (sample count, what one sample is, order). The worker records both in its result.

## Phase B: Fan out

Start all N workers in one fan-out phase through provider dispatch. Native lanes use background subagents; external lanes invoke the launcher as background work with retained task/session handles. Never use Claude's foreground Bash path for a long worker. Every writer runs in its assigned worktree or output directory. Isolation comes from those paths, not the provider.

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. A worker that can prove a defect reports `ISSUES` and lists every issue it can prove, not only the first.

If the helper stops a worker or its chain is exhausted, proceed with N-1 and note the provider, model, and receipt failure. If it returns `inspect`, preserve and inspect that writer before aggregation. Report the actual provider distribution across completed workers; a fallback keeps the seat but may reduce diversity — say so. Never substitute another provider silently.

## Phase C: Aggregate

Read the terminal results. Drop a result that does not record the SHAs and method its brief names, and respawn that worker once. After a second miss, record a gap. A gap does not count as a pass. 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.