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.

Start

Open a todo list 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 concurrency limit.
4. Pick the worker model with pstack_models role swarm-workers (default @task). If the tool is absent, read rule://pstack-models for the swarm-workers line and use the default. Pass each returned selector as the task item's model. If a selector is rejected, use the default and say so. For a model race, name each arm's model 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

Spawn all N workers in one task batch, or push them into an eval workpool when N is large or results should stream back. Use agent task for writers, and scout or reviewer for read-only verification lanes. Pass the step 4 model. Writers that might collide set isolated: true so each gets its own git worktree. That flag only exists when task.isolation.enabled is on (default off; see the setup-pstack skill), and with task.isolation.apply on (the default once isolation is enabled) successful worktree changes are applied back to the parent checkout. When isolation is off, create the worktrees yourself with /wt, or run one writer at a time.

When a worker must start from a non-default branch, name the branch in its brief and have it check that branch out first.

When the swarm verifies a PR, the two thermo lenses are mandatory lanes, run through the thermos skill: agents thermo-review and thermo-quality, scoped to the same diff, launched as items of one task call with heterogeneous agent values (not a workpool, which would drop their structured output). The swarm's own lanes are the coverage-matrix, race, and gauntlet lanes. The thermo lanes never substitute for them and they never substitute for the thermo lanes.

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

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.