premortem

Runs structured premortem sessions that find failure modes in plans and persist results to Markdown files.

58|10|Updated May 9, 2026
One-click install
npx skills add https://github.com/AndyShaman/premortem --skill premortem-andyshaman
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: premortem
Source: https://github.com/AndyShaman/premortem/tree/main/premortem
Command: npx skills add https://github.com/AndyShaman/premortem --skill premortem-andyshaman

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires pyyaml, jsonschema, click, and includes scripts (resource) and references (resource) and assets (resource) components.

What problem does it solve? LLMs default to polite, hedged risk lists when asked to evaluate a plan. This Skill reframes the question as a past-tense failure narrative ("the plan has already failed — explain how"), producing concrete, specific failure causes instead of generic caveats, and records decisions so they can be revisited later. ## Core Features & Use Cases - Four-phase session: pre-flight context sync, silent scan with three parallel helpers covering six angles, live decision dialog per hole, and atomic persistence to docs/premortem/<plan>.md with history snapshots. - Deterministic mechanics via CLI scripts: plan-type classification, helper-response JSON schema validation, hash-based dedup, stable H-NNN hole IDs, and atomic file writes with locking. - Bias check and conditional reverse-premortem: a 6-item bias checklist (Kahneman/Lovallo/Sibony) on the top picks, plus a reverse-premortem when the recommendation is delay, reduce stake, or abort. - Use Case: Before launching a paid workshop, run a premortem to surface 5–8 concrete failure holes (pricing, audience, competition), pick mitigations for each, and re-run a month later to compare which holes closed or worsened. ## Quick Start Ask the assistant to run a premortem on your concrete launch or decision plan, for example: "Run a premortem on my plan to launch a paid workshop for marketing teams."

Frequently Asked Questions about premortem

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I run a premortem on a product launch plan?

Invoke the skill with a concrete plan, for example "run a premortem on my launch plan." The session collects subject, audience, success criterion, and evaluation horizon, then three parallel helpers scan six angles and present 5–8 holes for you to decide on.

What is a premortem and how is it different from a risk assessment?

A premortem assumes the plan has already failed and asks how it died, using past-tense framing. Research (Mitchell, Russo & Pennington 1989) shows this produces about 30% more specific causes than conditional "what could go wrong" framing, which tends to yield hedged generic risk lists.

When should I not use a premortem session?

Skip it for vague ideas without a concrete plan, questions with one right answer, creative editing of drafts, and already-irreversible decisions. The skill requires a specific plan with a reversible choice and about 10–15 minutes of your time.

Where are premortem results saved and can I re-run them?

Results are written atomically to docs/premortem/<plan-name>.md with a timestamped snapshot in a history/ subdirectory. Re-running on the same plan updates hole statuses (same, worse, resolved, new) so you can compare sessions over time.

What happens if a helper returns invalid output during the scan?

Each helper response is validated against a JSON schema with up to three retries using targeted correction messages. If it still fails, that helper's response is discarded and the session continues with the remaining valid results.