pre-mortem（验尸前）

Pre-Mortem Skill

Purpose: Is this plan/spec good enough to implement?

Mandatory for 3+ issue epics. Pre-mortem is enforced by hook when /crank is invoked on epics with 3+ child issues. 6/6 consecutive positive ROI. Bypass: --skip-pre-mortem flag or AGENTOPS_SKIP_PRE_MORTEM_GATE=1.

Run /council validate on a plan or spec to get multi-model judgment before committing to implementation.

Quick Start

/pre-mortem                                         # validates most recent plan (inline, no spawning)
/pre-mortem path/to/PLAN.md                         # validates specific plan (inline)
/pre-mortem --deep path/to/SPEC.md                  # 4 judges (thorough review, spawns agents)
/pre-mortem --mixed path/to/PLAN.md                 # cross-vendor (Claude + Codex)
/pre-mortem --preset=architecture path/to/PLAN.md   # architecture-focused review
/pre-mortem --explorers=3 path/to/SPEC.md           # deep investigation of plan
/pre-mortem --debate path/to/PLAN.md                # two-round adversarial review

Execution Steps

Step 0: Bead-Input Pre-Flight (Mandatory)

When the input to /pre-mortem is a bead ID (matches pattern [a-z]{2,6}-[0-9a-z.]+) AND complexity is "full" OR the bead is older than 7 days OR the bead description was filed by a prior session, automatically run ao beads verify <bead-id> as the very first action. If verify reports any STALE citations, present them to the user and ask for scope re-validation before proceeding. This implements the shared stale-scope validation rule.

Step 1: Find the Plan/Spec

If path provided: Use it directly.

If no path: Find most recent plan:

ls -lt .agents/plans/ 2>/dev/null | head -3
ls -lt .agents/specs/ 2>/dev/null | head -3

Use the most recent file. If nothing found, ask user.

Step 1.4: Retrieve Prior Learnings & Compiled Prevention (Mandatory)

Run ao lookup for the plan's domain, then load compiled checks from .agents/pre-mortem-checks/*.md (fall back to .agents/findings/registry.jsonl). Include matched entries in the council packet as known_risks and record ao metrics cite influence. Full contract (fail-open rules, section-evidence handling, ranking heuristics, citation lifecycle) in references/compiled-prevention.md. This file also contains Step 1a (flywheel search, skipped under --quick) and Step 1b (PRODUCT.md auto-include).

Fail-open reader behavior is mandatory: missing or empty compiled prevention inputs skip silently; malformed line -> warn and ignore that line; unreadable file -> warn once and continue without findings.

Step 1a: Flywheel Search (Skip if --quick)

Run the flywheel search from references/compiled-prevention.md unless --quick is active.

Step 1b: PRODUCT.md Context (Skip if --quick)

When PRODUCT.md exists and full council mode is active, add one product judge: 3 judges total (2 plan-review + 1 product).

Step 1.5: Fast Path (--quick mode)

By default, pre-mortem runs inline (--quick) — single-agent structured review, no spawning. This catches real implementation issues at ~10% of full council cost (proven in ag-nsx: 3 actionable bugs found inline that would have caused runtime failures).

In --quick mode, skip Steps 1a and 1b as standalone pre-processing phases. If PRODUCT.md exists, Step 1b's product context is still loaded inline during the quick review. --deep, --mixed, --debate, and --explorers add the dedicated product perspective and wider council fan-out.

To escalate to full multi-judge council, use --deep (4 judges) or --mixed (cross-vendor).

Step 1.6: Scope Mode Selection

Determine review posture — EXPANSION, HOLD SCOPE, or REDUCTION — and commit scope_mode: <expansion|hold|reduction> in the council packet. Auto-detection rules and mode-specific judge prompts are in references/scope-mode.md.

Step 1.7: Load Council FAIL Patterns (Mandatory)

Read references/council-fail-patterns.md for the top 8 council FAIL patterns to check against. These patterns are derived from 124 analyzed FAIL verdicts across 946 council sessions. They apply to both --quick and --deep modes.

Step 2: Run Council Validation

Default (inline, no spawning):

/council --quick validate <plan-path>

Single-agent structured review. Catches real implementation issues at ~10% of full council cost. Sufficient for most plans (proven across 6+ epics).

Default (2 judges with plan-review perspectives) applies when you intentionally run non-quick council mode.

With --deep (4 judges with plan-review perspectives):

/council --deep --preset=plan-review validate <plan-path>

Spawns 4 judges:

• missing-requirements: What's not in the spec that should be? What questions haven't been asked?
• feasibility: What's technically hard or impossible here? What will take 3x longer than estimated?
• scope: What's unnecessary? What's missing? Where will scope creep?
• spec-completeness: Are boundaries defined? Do conformance checks cover all acceptance criteria? Is the plan mechanically verifiable?

Use --deep for high-stakes plans (migrations, security, multi-service, 7+ issues).

With --mixed (cross-vendor):

/council --mixed --preset=plan-review validate <plan-path>

3 Claude + 3 Codex agents for cross-vendor plan validation with plan-review perspectives.

With explicit preset override:

/pre-mortem --preset=architecture path/to/PLAN.md

Explicit --preset overrides the automatic plan-review preset. Uses architecture-focused personas instead.

With explorers:

/council --deep --preset=plan-review --explorers=3 validate <plan-path>

Each judge spawns 3 explorers to investigate aspects of the plan's feasibility against the codebase. Useful for complex migration or refactoring plans.

With debate mode:

/pre-mortem --debate

Enables adversarial two-round review for plan validation. Use for high-stakes plans where multiple valid approaches exist. See /council docs for full --debate details.

Steps 2.4–2.8: Mandatory Council Checks

Five mandatory checks run during council validation — temporal interrogation, error-&-rescue map, council FAIL pattern check, test pyramid coverage, and input validation for enum-like fields. Each has auto-trigger conditions and judge-prompt snippets. Full step text and check tables in references/mandatory-checks.md.

Step 3: Interpret Council Verdict

Step 4: Write Pre-Mortem Output

Write to .agents/council/YYYY-MM-DD-pre-mortem-<topic>.md using the full template (frontmatter, verdict table, pseudocode-fix format, decision gate) in references/write-pre-mortem-output.md. That reference also contains Step 4.5 (persist reusable findings to .agents/findings/registry.jsonl) and Step 4.6 (copy pseudocode fixes verbatim into plan issues so workers do not reimplement them from scratch).

When Step 4.5 writes reusable findings, include dedup_key and refresh compiled findings with finding-compiler.sh when that hook exists.

The generated report must preserve this exact heading because ao rpi phased extracts verdicts with a regex anchored to it:

Council Verdict: PASS / WARN / FAIL

Step 5: Record Ratchet Progress

ao ratchet record pre-mortem 2>/dev/null || true

Step 6: Report to User

Tell the user:

1. Council verdict (PASS/WARN/FAIL)
2. Key concerns (if any)
3. Recommendation
4. Location of pre-mortem report

Integration with Workflow

/plan epic-123
    │
    ▼
/pre-mortem                    ← You are here
    │
    ├── PASS → /implement
    ├── WARN → Review, then /implement or fix
    └── FAIL → Fix plan, re-run /pre-mortem

Examples & Troubleshooting

See references/examples.md for worked examples (default inline, --mixed cross-vendor, auto-find recent, --deep high-stakes) and the troubleshooting table (timeouts, FAIL on valid plans, missing product perspectives, gate-blocking, spec-completeness warnings, mandatory-for-epics enforcement).

Troubleshooting

See references/examples.md for the troubleshooting table.

See Also

• skills/council/SKILL.md — Multi-model validation council
• skills/plan/SKILL.md — Create implementation plans
• skills/vibe/SKILL.md — Validate code after implementation

Reference Documents

• references/compiled-prevention.md
• references/scope-mode.md
• references/mandatory-checks.md
• references/write-pre-mortem-output.md
• references/examples.md
• references/council-fail-patterns.md
• references/enhancement-patterns.md
• references/error-rescue-map-template.md
• references/failure-taxonomy.md
• references/simulation-prompts.md
• references/prediction-tracking.md
• references/spec-verification-checklist.md
• references/temporal-interrogation.md
• Shared stale-scope validation rule — re-validate inherited scope estimates against HEAD before acting on deferred beads or handoff docs.