swarm

# Swarm Fan out N parallel Task 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 Task concurrency limit. 4. Pick the worker model from `swarm workers` in `instructions/pstack-models.instructions.md` in Copilot home (`$COPILOT_HOME`, or `$HOME/.copilot` when unset) when present. Otherwise omit `model`. For a model race, name each arm's model up front. 5. Give each worker its own writable output when it writes. Use a worktree, branch, or a worker-specific directory under the session artifact directory. ## Phase B: Fan out Spawn all N workers in one message with `agent_type: "general-purpose"` and `mode: "background"`. Pass the configured model unless it is absent or set to `auto`. 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.