execute-task

name	execute-task
description	Execute the next TaskMaster task using the implementation plan with CDD verification. Picks the next ready task, matches it to the plan step, implements via a dispatched subagent, verifies subtasks with evidence, marks the task done, and loops until every task is complete. Wraps the TaskMaster next -> in-progress -> done lifecycle with CDD GREEN / RED / BLUE verification and the plugin's triple-verification rule. Autonomous by design — no user prompts inside the loop.
user-invocable	true
allowed-tools	["Read","Write","Edit","Bash","Skill","Agent","ToolSearch","mcp__atlas-engine","mcp__plugin_prd_go","mcp__plugin_prd-taskmaster_go","mcp__plugin_atlas-go_go"]

execute-task

The execution loop. Three sources converge:

• Plan (HOW) — docs/superpowers/plans/*.md produced by GENERATE
• TaskMaster (WHAT) — .taskmaster/tasks/tasks.json with dependencies and complexity scores
• CDD (PROOF) — acceptance cards per task, evidence-gated

execute-task is the single skill that runs the full build from "tasks are ready" to SHIP_CHECK_OK. It is autonomous — no AskUserQuestion inside the loop. Any gap that would require user input is surfaced through the recon escalation ladder (step 11) or the inbox (steps 4 and 8), never via a modal prompt.

Entry

This skill is invoked either:

1. Directly by the user once HANDOFF has completed and a task-execution mode (A/B/C) has been dispatched, or
2. By the prd-taskmaster orchestrator when current_phase is EXECUTE.

On entry, confirm that:

• .atlas-ai/state/pipeline.json exists and records phase: EXECUTE
• .taskmaster/tasks/tasks.json exists with at least one ready task
• .atlas-ai/customizations/system-prompt-template.md is present (may be empty — absence is a setup bug, empty is fine)

If any of the above are missing, report the gap and halt. Do NOT attempt to bootstrap the missing artifact from inside this loop — that is the orchestrator's job.

Cycle (per iteration)

Each pass through this cycle moves exactly one TaskMaster task from pending to done. Do the 13 steps in order. Do not skip.

Task-start SHA — at the very beginning of each iteration (before step 2), capture the current git HEAD:

task_start_sha=$(git rev-parse HEAD)

Record $task_start_sha in the execute-log row for this iteration. It is the oracle of truth for every reachability sweep in step 9b below: "what modules did THIS task add?" is diff $task_start_sha..HEAD. The oracle flow already issues per-task start commits; this surfaces the same value in the loop prose.

1. Heartbeat check: verify the execute-task heartbeat timer is running. If missing, register one via CronCreate("execute-task-heartbeat", "* * * * *", "echo heartbeat"). Abort the iteration if the timer cannot be created — a missing heartbeat means a missing stuck-session detector, and that is load-bearing.

2. Inbox reconciliation: read .atlas-ai/state/pipeline.json, .taskmaster/tasks/tasks.json, and the current TodoWrite list. Diff them. If the three are stale by more than 5 tasks (i.e. TodoWrite says 10 done but tasks.json says 3 done), report the diff and halt — do not paper over bookkeeping drift by silently reconciling.

3. Pick next task: run backend op next with the plugin's project-root pointer. Use exactly this invocation:

   python3 script.py next-task
   

   Parse the JSON result.

   • If no ready tasks and all tasks are done, run .atlas-ai/ship-check.py, emit SHIP_CHECK_OK on success, exit the loop.
   • If no ready tasks but pending tasks exist, the dependency graph is deadlocked — report and halt.

4. Load plan step: search for the matching task ID in this priority order, halting only after all three fail:

   1. docs/superpowers/plans/*.md (the superpowers GENERATE default output)
   2. .taskmaster/docs/plan.md (the prd-taskmaster HANDOFF default output, whose path is also recorded in pipeline.json:phase_evidence.HANDOFF.plan_file_path)
   3. Any custom path declared in pipeline.json:phase_evidence.HANDOFF.plan_file_path (in case a future handoff variant writes elsewhere)

   If none of the three contains the matching task ID, the task was invented downstream of the plan — mark the task blocked, inbox the parent orchestrator with message_type="blocker", and continue to the next iteration.

   (Codified 2026-06-04 — yesterday's ai-human-tasker run had its plan at .taskmaster/docs/plan.md only, while this step previously read docs/superpowers/plans/*.md exclusively. The controller silently improvised; a cold-start successor would have hit the blocked path on every task.)

5. Generate CDD card: convert the task's subtasks field into a testing_plan. Each subtask becomes a verifiable check with a concrete evidence path (file, command output, or test name). Write the card to .atlas-ai/cdd/task-<id>.json. A task without subtasks is treated as a single RED card.

6. Set in-progress: run backend op set-status from the current project root:

   python3 script.py set-status --id <N> --status in-progress
   

   This flip is observable by watchers and anchors the iteration in TaskMaster itself.

7. Dispatch implementer subagent — NEVER in-session. The controller must:

   • Provide the FULL task text to the subagent. Never tell the subagent to "read tasks.json" — per spec §12, the controller serialises the task into the dispatch prompt.
   • Inject the plugin customisation block at .atlas-ai/customizations/system-prompt-template.md into the subagent's system prompt. If the file is empty, inject nothing and continue.
   • Tier the model by TaskMaster complexity score:
     • 1-4 fast — use the fast tier (Haiku-class)
     • 5-7 standard — use the standard tier (Sonnet-class)
     • 8-10 capable — use the capable tier (Opus-class)
   • Wait for the subagent to return a terminal status: DONE, DONE_WITH_CONCERNS, NEEDS_CONTEXT, or BLOCKED.

   Rationale: complexity-tiered dispatch keeps the dollars-per-task curve sensible. A complexity-2 boilerplate task does not need Opus; a complexity-9 architectural task should not be given to Haiku.

8. Route by status: the subagent's return status drives the next move.

   • DONE — proceed to the spec gate, then the quality gate. If both pass, advance to step 9.
   • DONE_WITH_CONCERNS — the subagent completed but flagged concerns. Address each concern before advancing; re-dispatch if needed.
   • NEEDS_CONTEXT — the subagent requested more context. Provide the requested context and re-dispatch. Retry cap at 2 — if the subagent still returns NEEDS_CONTEXT after two re-dispatches, escalate via the recon ladder (step 11).
   • BLOCKED — the subagent cannot proceed. Try one model-tier upgrade first (e.g. standard -> capable). If still blocked, break the task into smaller subtasks via backend op expand (python3 script.py expand --id <N>). If still blocked, set status=blocked, inbox parent, halt this iteration.

   Do NOT invent new status values. The four above are the only terminal returns. Any other string from the subagent is a protocol violation and should be logged + treated as BLOCKED.

9. Triple verification — the plugin's core quality gate, per spec §11.4. Three independent checks must agree.

   Hard exit-code gate (MANDATORY — bypasses agreement count). Before invoking the three checkers, run .atlas-ai/ship-check.py --dry-run. If it reports any non-zero Exit status N in evidence files, the task FAILS regardless of how the agent narratives read. SHIP_CHECK_FAIL is NOT a warning. Narrative claiming the exit code is "expected" or "infrastructure noise" does NOT override this gate — write a separate task-fix-N to address the underlying failure instead. There is NO override path; Gate 5 is unfakable. (Codified 2026-06-04 after T12 in ai-human-tasker was marked DONE while pnpm test exited 1 with 11 failing tests.)

   9b. Reachability sweep (MANDATORY for wired/live tasks). After the hard exit-code gate passes, run the reachability sweep for this task:

   python3 script.py reachability-sweep \
       --task <task_id> \
       --start-commit <task_start_sha>
   

   This command:

   • Inspects every source module added between $task_start_sha and HEAD.
   • Computes a per-task verdict: WIRED, EXEMPT, ORPHAN, or ERROR.
   • Writes the verdict dict into the task's CDD card .atlas-ai/cdd/task-<id>.json under the "reachability" key (atomic, additive — existing card keys are preserved).

   The sweep exit code encodes the verdict:

   • exit 0 → WIRED or EXEMPT (pass; proceed to the three checkers).
   • exit 1 → ORPHAN or ERROR (see step 10 for the auto-downgrade path).

   For spike/domain-model tasks the sweep returns EXEMPT automatically (no importer search is performed for those tiers).

   Why sweep before the triple check? A green test on a module imported by nothing is not "done" — it is scaffolded. The triple check can pass for an ORPHAN module (all tests pass; doubt and validate agree). The reachability gate closes that gap: done means the module is reachable from real production callsites, not just reachable from tests. Wire it or it ships as scaffold.

   The three checks (run only if the hard gate AND the reachability sweep both pass):

   • Plugin-native check: evidence file count vs declared subtask count (from the CDD card in step 5). Missing evidence = fail.
   • /doubt skill — adversarial doubt sweep on the claimed completion.
   • /validate skill — deterministic validation pass (lint / tests / exit codes).
   • External Opus subagent sanity pass — asks a fresh subagent "would you merge this?" with the task spec + diff + evidence.

   3+ agree pass -> task passes. Disagreement -> halt this iteration, surface to inbox.

10. Mark done + propagate state — branch on the sweep verdict from step 9b:

    WIRED or EXEMPT (sweep exit 0) → proceed normally:

    a. Run backend op set-status for the parent task. Because the sweep already wrote the reachability block into the CDD card, the set-status CLI auto-reads it — no --reachability flag needed:

    python3 script.py set-status --id <N> --status done
    

    If you want to be explicit (e.g. for logging), you may pass: --reachability WIRED or --reachability EXEMPT.

    b. Subtask writeback: for each subtask S in task.subtasks whose evidence file (per the CDD card from step 5) exists, run python3 script.py set-status --id <N>.<S> --status done. Subtasks left pending while the parent is done are a data-integrity violation that breaks any tool computing progress from subtask state. (Codified 2026-06-04 — yesterday's run left all 39 subtasks pending despite 13/13 parent tasks done.)

    c. Update .atlas-ai/state/pipeline.json per-task: call mcp__plugin_prd_go__update_pipeline_task_status(task_id=<N>, status="done") if the MCP tool is available. If not, fall back to atomic read-modify-write using the pattern in mcp-server/pipeline.py:locked_update() — read, append <N> to phase_evidence.EXECUTE.tasks_completed, write to temp, rename. Never leave pipeline.json and tasks.json mutually inconsistent. (Codified 2026-06-04 — yesterday's run promised this write in SKILL.md but never executed it. pipeline.json froze at HANDOFF transition through all 85 minutes of execution.)

    ORPHAN or ERROR (sweep exit 1) → auto-downgrade to scaffold:

    Do NOT mark the task done. Instead:

    python3 script.py set-status --id <N> --status scaffold
    

    Then:

    • Log to execute-log.jsonl: "reachability_verdict": "ORPHAN" (or "ERROR"), "auto_downgraded": true, and a plain-English note of which modules are unwired (from the sweep's modules list in the CDD card).
    • Do NOT halt the loop — continue to the next task (step 1). An ORPHAN module is scaffolded work, not blocked work. The ship gate (Gate 6, RA3) will report it honestly as scaffold, not done.
    • If you need to wire the module, create a follow-up task (title: "Wire <module> into <entrypoint>") and append it via python3 script.py expand --id <N> or the MCP equivalent.

    Throughline: a green test on a module imported by nothing is not done — wire it or it ships as scaffold. The auto-downgrade ensures the task graph stays honest: Gate 6 will block the ship until every wired/live task's reachability block reads WIRED or EXEMPT. If all wired/live tasks auto-downgraded to scaffold, the ship check will block at Gate 2 ("not every task is done") and the developer must choose: wire the modules, re-tier them (spike/domain-model), or mark them explicitly exempt (reachableVia: cli:...). There is no silent path to SHIP_CHECK_OK with an unwired module at a wired/live tier.

11. Check stepback triggers: if 15 minutes have passed with no task moving to done, OR 5 consecutive iterations have failed on the same task class, the recon escalation ladder is MANDATORY. Climb the ladder in this exact order, not out of order:

    /stepback -> /research-before-coding -> /question -> pivot

    • /stepback — reassess the architectural assumption. Was the plan wrong?
    • /research-before-coding — feed the blocker into the Perplexity + Context7 + GitHub pipeline for fresh external context.
    • /question — batch-research the unresolved unknowns in parallel.
    • pivot — the plan step itself is unsound; kick the task back to the plan author (inbox parent with message_type="plan_pivot_requested").

    The ladder is append-only — if /stepback surfaces a fix, apply it and return to step 3. Only climb if the prior rung did not yield progress.

12. Render progress — show the execute progress panel: MCP render_status(phase="EXECUTE") → print its rendered field; CLI python3 script.py status --phase EXECUTE. Then emit the atlas-gamify one-line score (tasks done / tasks total, complexity-weighted). This is the human-visible progress signal and also feeds the dogfood debrief.

13. Loop: back to step 1 until SHIP_CHECK_OK or a halt condition fires.

Termination

The termination sequence is strict — three steps, in order, no shortcuts:

1. Run .atlas-ai/ship-check.py. If it does NOT exit 0, halt. Do NOT emit any completion signal. Investigate the gate failure, fix, retry.
2. MANDATORY: invoke Skill(skill: "sync") to refresh the memory bank (session-context/CLAUDE-*.md, MEMORY.md, capability inventory). This MUST happen BEFORE the SHIP_CHECK_OK token is printed. Orchestrators tail-watch the token; if the memory bank is stale when they react, successor sessions inherit a wrong picture of the world. (Codified 2026-06-04 — yesterday's ai-human-tasker run shipped 15.6k LOC while session-context/CLAUDE-activeContext.md still said "Scaffold complete. No application code yet".)
3. Print SHIP_CHECK_OK to stdout. This is the ONLY place in your output where the token may appear — emit it nowhere else, to avoid false-positive matches by log-watchers.

The ship-check script is deterministic. Its gates are documented at the top of ${CLAUDE_PLUGIN_ROOT}/skel/ship-check.py (copied to .atlas-ai/ship-check.py at setup):

• Gate 1: pipeline.json current_phase == "EXECUTE"
• Gate 2: every master.tasks[].status == "done"
• Gate 3: every task has a CDD card (task-<id>.json or combined variant)
• Gate 4: plan file exists at .taskmaster/docs/plan.md OR docs/superpowers/plans/*.md
• Gate 5 (HARD): no non-zero Exit status N line in any evidence file

Gate 5 is the convergent must-do from the 2026-06-04 audit — a "PASS" label on a non-zero-exit test is structurally impossible after this script runs. There is no override path for Gate 5; it is the unfakable oracle.

Do not emit SHIP_CHECK_OK on a mere "DONE" keyword in a subagent reply. Do not emit on "all tasks marked done" without the explicit ship-check. Do not emit before /sync has been called.

Red flags

These are the most common pressure points where the loop silently degrades from "verified" to "performative". If you catch yourself thinking any of them, stop and repair the gap.

• "Close enough, mark it done" -> NO. Evidence OR nothing.
• "Let me skip the doubt step this time" -> NO. Triple verification is non-negotiable.
• "I'll retry with same model+prompt" (BLOCKED) -> NO. Escalate.
• "The task says done, don't check evidence files" -> NO. Task status must reflect evidence.

Observability

Every iteration appends a structured row to .atlas-ai/state/execute-log.jsonl. Field types are strict — text narrative in a typed field is a logging bug, not compliance. The schema:

• iteration (integer, or "FINAL" for the terminal marker)
• timestamp (ISO 8601 string)
• task_id (string)
• complexity (integer or human label)
• tier (string: "fast" | "standard" | "capable")
• subagent_status (string: "DONE" | "DONE_WITH_CONCERNS" | "NEEDS_CONTEXT" | "BLOCKED")
• retry_count (integer)
• triple_verify (string: "PASS" / "FAIL" plus free-text rationale)
• stepback_triggered (boolean, REQUIRED — true iff /stepback was invoked this iteration). Putting narrative-text in this field is a violation; use stepback_narrative instead.
• stepback_narrative (string, nullable — explanation when stepback_triggered: true; null otherwise)
• ladder_rung (string, nullable — which rung was reached if escalated)
• gamify (string — atlas-gamify one-line score)

The stepback fields were split (2026-06-04) after a FINAL iteration entry wrote a paragraph of narrative into the boolean stepback field and was treated as compliance with the stepback_mandatory rule. Boolean trigger

• nullable narrative is the correct schema.

This log is the dogfood artifact — debrief tools consume it, the orchestrator greps it, and future runs read it for retrospective analysis.

Composition

• Orchestrator handoff: this skill is invoked post-HANDOFF. It does not call /handoff — that direction is one-way.
• Plan editing: if the plan is unsound, the ladder escalates to pivot, which inboxes the plan author. This skill does not mutate the plan in place.
• Ship-check: .atlas-ai/ship-check.py is the terminal gate. This skill calls it; it does not reimplement the checks.

Non-exits

This skill uses no explicit process termination. A halt condition reports the reason in the structured log and returns control to the caller (the user or the orchestrator). Never kill the shell — the caller owns the session lifecycle.