premortem

premortem is a skill for Claude Code, Codex from deciqAI/knowledge-skills. It costs 111 tokens per session (1,763 once invoked), scanned A, original, MIT.

A planning exercise in which a team imagines that its plan has already failed and then works backward to identify the causes.

In plain words
What is it for?
Use it before launches, major hires, contracts, spending decisions, project milestones, or other difficult-to-reverse commitments.
Why use it?
The failure-first perspective can reveal risks and disagreements that ordinary forward-looking discussion often misses.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it before launches, major hires, contracts, spending decisions, project milestones, or other difficult-to-reverse commitments.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/deciqai/knowledge-skills/premortem
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add deciqAI/knowledge-skills --skill premortem
Clone the repo
git clone --depth 1 https://github.com/deciqAI/knowledge-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for premortem

README.md
[![agentmods](https://agentmods.dev/badge/skills/deciqai/knowledge-skills/premortem/github.svg)](https://agentmods.dev/skills/deciqai/knowledge-skills/premortem)
Your own site
<a href="https://agentmods.dev/skills/deciqai/knowledge-skills/premortem"><img src="https://agentmods.dev/badge/skills/deciqai/knowledge-skills/premortem/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for premortem

Your own site · 80×15
<a href="https://agentmods.dev/skills/deciqai/knowledge-skills/premortem"><img src="https://agentmods.dev/badge/skills/deciqai/knowledge-skills/premortem.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 111 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,763 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Anti-Refusal · line 49
    Skill instructs the agent to omit warnings, disclaimers, or ethical commentary. Stripping safety caveats hides risk from the user and is a common jailbreak preamble.
    Fix: Remove instructions that suppress warnings, disclaimers, or ethical commentary. Let the agent surface safety-relevant caveats to the user.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00111 $0.01763
Opus 5 $0.00056 $0.00881
Sonnet 5 $0.00022 $0.00353
Haiku 4.5 $0.00011 $0.00176

Measured 8d ago against content hash 227aa37c9f41, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

premortem scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

premortem/SKILL.md · 125 lines

How it starts

The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Premortem

Overview

Before committing to a plan, the team imagines that plan has already failed catastrophically, then works backward to enumerate causes. The retrospective frame ("it failed — what caused it?") surfaces risks the prospective frame ("what could go wrong?") systematically misses. Gary Klein operationalized this in HBR (2007), grounded in Mitchell-Russo-Pennington (1989) showing prospective hindsight increases correct failure-mode identification by 30%.

Composes with inversion (premortem is inversion made operational), confirmation-bias (structural counter), hindsight-bias (leveraged as a feature), and critical-thinking.

When to Use

  • Before any high-stakes, hard-to-reverse decision (launch, major hire, contract, capital allocation)
  • When the team has converged quickly on a single plan with little visible dissent
  • When a previous similar effort failed and the team is about to repeat the pattern
  • At project milestones to identify emerging failure modes
  • Before committing to an AI product launch, model migration, or AI capex/growth spend where model commoditization, inference unit economics, a safety incident, or stretched AI valuations could break the plan within a year

Not when: small reversible decision; equivalent rigorous risk analysis already done; Chaotic domain (action before analysis); time-critical where premortem delays response.

Coaching Novices (Adaptive Front Door)

  • Engine mode: user has a concrete decision → run The Process directly.
  • Coach mode: user is new → guide step by step.

In Coach mode, respond one step at a time. Each [WAIT] is a hard stop — output only that step's question, then stop.

  1. One-line: imagine the project already failed — the retrospective frame surfaces risks "what could go wrong?" misses.
  2. Check fit: if the decision is small and reversible, skip.
  3. Elicit the specific decision, team, and imagined failure date.

[WAIT — do not advance until user responds]

  1. Run The Process one step at a time — enforce private generation before group discussion.

[WAIT — do not advance until user responds]

  1. Close by naming the insight uncovered and scheduling the re-premortem date.

[WAIT — do not advance until user responds]

Read the full file on GitHub · 125 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 125 lines · 111 tokens per session scan A 227aa37c9f41

Subscribe to this mod's changes

premortem is a skill published in the GitHub repository deciqAI/knowledge-skills (10 stars, last pushed 10d ago), licensed MIT. It adds 111 tokens to every session and 1,763 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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