wave-based-dispatch

Wave-Based Dispatch

The agent-side dispatch discipline for sequential WO chains. Same pillars as parallel-agent-dispatch — disjoint ownership, return contracts, shared-file exclusion — but the gates between waves are different from the gates inside a wave. This skill is those between-wave gates.

When to Use This Skill

The three skills compose: each wave is itself a parallel-agent-dispatch, lock-holding waves use exclusive-lock-dispatch for the pre-dump, and this skill covers the boundary between waves.

Picking Wave-Based Over Parallel

If any trigger matches, the work belongs in waves. Inside each wave, parallel-agent-dispatch still applies as the per-agent contract.

The Research-Before-WO Gate

When the scope of a downstream WO depends on information that only a tool run can produce — Ghidra decomp, a live API trace, the actual structure of a binary format, a benchmark — run that probe as its own first wave before the implementation WO is written.

The reason is concrete: the implementation WO's size collapses once the probe lands. A WO scoped as "unknown — possibly days, depends on the binary's actual layout" turns into "plumb a known pointer from offset 0x40 to the existing decoder, hours" once the research wave produces a spec artefact. Writing the brief before the research lands locks in the worst-case framing and the agent burns its window re-deriving the information.

Process:

1. Wave 1 brief asks the probe agent to write findings to gitignored scratch (tmp/research/format-spec.md, tmp/decomp/strings.txt, tmp/api/probe-results.json).
2. Probe agent returns a Return Contract that lists the artefact paths.
3. Implementation WO is written after wave 1 closes, citing those paths verbatim and forbidding re-running the probe.
4. If the artefacts are insufficient, the implementation agent returns partial with the missing question in Orchestrator action needed, and the orchestrator dispatches a follow-up probe wave rather than letting the implementation agent improvise.

See agent-patterns-plugin:exclusive-lock-dispatch when the probe tool holds an exclusive lock — the pre-dump mechanics there are the right shape for the research wave's brief.

The Pilot-Before-Fan-Out Gate

When the same transformation will be applied to N items (repos, files, packages, services), validate the whole recipe on one representative pilot end-to-end — including the riskiest unknown — before fanning out. Wave 1 is the pilot; wave 2 is the fan-out, and it mirrors the landed pilot rather than re-deriving the recipe N times in parallel.

The reason is concrete: a parallel fan-out over an unvalidated recipe multiplies a single wrong assumption into N broken outputs, and you pay for all N before discovering the flaw. Proving it once converts the fan-out agents' job from "figure out how" to "replicate this exact, working example" — which is both cheaper and far more reliable.

Process:

1. Wave 1 = the pilot. Pick the simplest representative item. Do the full transformation, and explicitly confirm the load-bearing unknown — the one thing that, if it didn't work, would invalidate the entire approach (a build externalization, an API contract, a migration codemod's output).
2. Gate. The pilot's own gates (build/test/lint) must pass and the risky unknown must be confirmed before any fan-out brief is written.
3. Wave 2 = the fan-out. Each agent is told to mirror the landed pilot — cite its path verbatim as the reference implementation — with per-item detection only for the parts that genuinely vary.
4. If the pilot reveals the approach is wrong, re-plan. Cheap, because only one item was touched.

Distinct from the Research-Before-WO Gate above: research produces a spec / artefact to scope an unknown ("what should we build?"); a pilot produces a working reference implementation of a repeatable change ("we know what to build — is the recipe sound, and does the risky step actually work?"). Reach for research when the scope is unknown; reach for a pilot when the scope is known but the recipe is unproven.

Six-Gate Verification Table Between Waves

No brief for wave N+1 is written until wave N's gates pass. The gate set is fixed — drifting the gates between waves is how regressions slip in.

A gate failure rolls back to fix in place, retry the gate — never to "dispatch wave N+1 and paper over it." If the wave is unrecoverable, revert it and re-brief.

Gating on a green PR vs a landed merge

The six gates assume wave N landed on main (Gate 6: clean tree). That holds when the orchestrator merges each wave itself. But when a human reviews and merges — so waves can't land before wave N+1 is due — don't stall the pipeline waiting for the merge. Gate wave N+1 on wave N's foundation PR being green (CI passing on the open PR) and stack wave N+1 on wave N's branch (gh pr create --base <wave-N-branch>), so it builds on wave N's content without waiting on the merge. Two adjustments:

• Gate 6 becomes "wave N's PR is green," not "merged." Gates 1–5 (build, tests, smoke, task/tracker drain) still apply — run them on wave N's branch.
• CI scoped to pull_request: [main] does not run on the stacked children (their base is a feature branch), so their gate is a local build/test until they're retargeted to main.
• Honor stacked-PR merge order at landing time: retarget children to main before the base PR merges and deletes its branch, then rebase --onto origin/main <old-base-tip> to drop the squashed base commits. See git-plugin:git-pr (Stacked PRs) and git-plugin:git-conflicts (rerere can replay the resolution across the base merge and each child rebase).

The ~10-Line Inline-Fix Threshold

When a wave returns and a small bug surfaces during the orchestrator's apply step, the orchestrator has a choice: fix it inline, or file a follow-up WO for the next wave. The threshold is approximate but load-bearing:

The deciding question is: "Will the orchestrator spend less time fixing in place than re-writing a brief and re-loading the agent's context?" Below ~10 lines, usually yes. A concrete signal that the threshold was right: a bug that was a missing branch in --no-present mode landed as a one-edit orchestrator fix instead of a whole re-dispatch turn.

This is not an excuse to skip waves entirely — it is a release valve for the small issues that always surface at apply time. Use it sparingly; once the inline fix exceeds ~10 lines, file the WO.

Stable Shared-File Exclusion List Across Waves

parallel-agent-dispatch §Shared-File Exclusion List defines the orchestrator-only files that no agent may touch (manifest, tracker, top-level plan, build manifests, justfile, task store). That list is derived once in the wave-1 brief and referenced by name in every subsequent wave's brief. Do not re-derive it.

Re-deriving the list per wave drifts it — wave 2 forgets the Cargo.toml entry that wave 1 had, wave 3 forgets the tracker, and on the Nth wave a silent manifest clobber lands. The discipline is:

• Wave 1 brief spells out the full exclusion list under ### Orchestrator-only files.

• Wave N+1 brief says, verbatim:

  "Orchestrator-only files: as defined in the wave-1 brief. No additions, no removals. If you believe a new file belongs on the list, return partial and surface it in Orchestrator action needed — do not edit it."

The same discipline applies to pre-allocated blueprint IDs, ADR numbers, and any monotonic counters (parallel-agent-dispatch §Pre-Allocated Blueprint IDs). Allocate up front; reference by ID in later waves.

Composition

This skill is the dispatch-time discipline that ties them together — the agent-pattern view of why the chain is sequential and what the between-wave gates buy you.

Quick Reference

Orchestrator Checklist

• Trigger identified (dependency chain / shared lock / orchestrator-edit contention)
• Research probe scheduled as wave 1 if any downstream scope is unknown
• Six-gate verification table applied at every wave boundary
• Shared-file exclusion list cited in wave 1, referenced by name in waves 2..N
• Return Contract referenced from parallel-agent-dispatch, never redefined
• Inline-fix threshold (~10 lines) honoured at wave-end
• No brief for wave N+1 written until wave N's gates pass

Common Mistakes

Related

• agent-patterns-plugin:parallel-agent-dispatch — intra-wave contract; the §Worktree Preflight, §Scope Budget, §Return Contract, and §Shared-File Exclusion List sections apply unchanged inside every wave
• agent-patterns-plugin:exclusive-lock-dispatch — pre-dump mechanics for lock-contending waves; this skill cites it as the right shape for the research wave's brief
• workflow-orchestration-plugin:workflow-wave-dispatch — workflow-side scheduling view: enumerating waves, gate-failure rollback, scheduling heuristics
• git-plugin:git-pr / git-plugin:git-conflicts — stacked-PR merge order (retarget children before deleting the base, --onto squash cleanup) and pre-merge trial integration for landing a wave's PRs
• rust-plugin:cargo-worktree-builds — when the waves are Rust worktrees, share one pre-warmed CARGO_TARGET_DIR so deps compile once across all worktrees
• taskwarrior-plugin:task-coordinate — where wave candidates come from: surfaces the next N unblocked tasks while excluding lock-contenders
• .claude/rules/parallel-safe-queries.md — empty-result exit codes that bite inside automated gate checks

Evidence: porting the 158-line wave-based-dispatch project rule (skullcaps-native, 2026-04-24) into a reusable skill. The rule earned promotion after a six-wave dependent landing shipped in one day with zero merge conflicts, one inline fix, and zero exclusion-list drift across waves.