Pre-Mortem Skill
Purpose: Is this plan/spec good enough to implement?
Mandatory for 3+ issue epics. Pre-mortem is enforced by hook when/crankis invoked on epics with 3+ child issues. 6/6 consecutive positive ROI. Bypass:--skip-pre-mortemflag orAGENTOPS_SKIP_PRE_MORTEM_GATE=1.
Loop position
Pre-flight check between moves 3 (slice plan) and 4 (TDD per slice) of the [operating loop](../../docs/architecture/operating-loop.md). Consumes the [slice validation plan](../../docs/templates/slice-validation.md); produces a PASS/WARN/FAIL verdict on the plan AND on the wave-validity rows (distinct write scopes, no shared migration/contract/CLI surface, owner per slice, discard path per slice). A wave can only be claimed parallel if pre-mortem confirms every conflict-free row. FAIL on wave-validity → run slices sequential or send the plan back to /plan for re-slicing.
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 reviewExecution 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 -3Use 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](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](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](references/scope-mode.md).
Step 1.7: Load Council FAIL Patterns (Mandatory)
Read [references/council-fail-patterns.md](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.mdExplicit --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 --debateEnables 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](references/mandatory-checks.md).
When a plan introduces a regex, grep, glob, or similar scope predicate, also apply [references/scope-predicate-positive-negative-cases.md](references/scope-predicate-positive-negative-cases.md): require positive and negative examples before approval.
Step 3: Interpret Council Verdict
| Council Verdict | Pre-Mortem Result | Action | |-----------------|-------------------|--------| | PASS | Ready to implement | Proceed | | WARN | Review concerns | Address warnings or accept risk | | FAIL | Not ready | Fix issues before implementing |
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](references