postmortem

postmortem is a skill for Claude Code from alirezarezvani/claude-skills. It costs 60 tokens per session (1,758 once invoked), scanned A, original, MIT.

A structured review of an event that went badly, such as a failed launch, missed target, or poor hire. It uses a blameless “5 Whys” investigation—repeatedly asking why—to find underlying causes and record changes.

In plain words
What is it for?
Use it after product launches, releases, deals, hiring decisions, or business targets that did not meet expectations.
Why use it?
It replaces blame or vague lessons with a clearer account of what happened and what should change. This helps teams reduce the chance of repeating the same failure.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the executive-mentor plugin — 6 skills, 1 agent shipped together

Good fit Use it after product launches, releases, deals, hiring decisions, or business targets that did not meet expectations.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/alirezarezvani/claude-skills/postmortem
About the project

claude-skills is a large collection of reusable skills, commands, plugins, and supporting resources for coding agents across engineering, business, research, compliance, and productivity work. It is used by people who want agents such as Claude Code, Codex, Gemini CLI, or Cursor to follow specialized workflows. The catalogue contains selected skills and settings from the collection.

alirezarezvani/claude-skills · 28,607 stars · on GitHub · alirezarezvani.medium.com

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 alirezarezvani/claude-skills --skill postmortem
Clone the repo
git clone --depth 1 https://github.com/alirezarezvani/claude-skills

Made for: Claude Code.

Or install executive-mentor, the plugin that ships this one along with the rest of its 6 skills, 1 agent.

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 postmortem

README.md
[![agentmods](https://agentmods.dev/badge/skills/alirezarezvani/claude-skills/postmortem/github.svg)](https://agentmods.dev/skills/alirezarezvani/claude-skills/postmortem)
Your own site
<a href="https://agentmods.dev/skills/alirezarezvani/claude-skills/postmortem"><img src="https://agentmods.dev/badge/skills/alirezarezvani/claude-skills/postmortem/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 postmortem

Your own site · 80×15
<a href="https://agentmods.dev/skills/alirezarezvani/claude-skills/postmortem"><img src="https://agentmods.dev/badge/skills/alirezarezvani/claude-skills/postmortem.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 60 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,758 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
  • Socket pass 16 Sept 2026
  • Snyk pass 16 Sept 2026
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 $0.00060 $0.01758
Opus 5.5 $0.00024 $0.00703
Sonnet 5.5 $0.00012 $0.00352
Haiku 4.5 $0.00006 $0.00176

Measured today against content hash ca1b7ab332c7, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

postmortem 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 today.

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.

c-level-advisor/executive-mentor/skills/postmortem/SKILL.md · 194 lines

How it starts

The opening of the file, as written. The whole thing — 194 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/em:postmortem — Honest Analysis of What Went Wrong

Command: /em:postmortem <event>

Not blame. Understanding. The failed deal, the missed quarter, the feature that flopped, the hire that didn't work out. What actually happened, why, and what changes as a result.


Why Most Post-Mortems Fail

They become one of two things:

The blame session — someone gets scapegoated, defensive walls go up, actual causes don't get examined, and the same problem happens again in a different form.

The whitewash — "We learned a lot, we're going to do better, here are 12 vague action items." Nothing changes. Same problem, different quarter.

A real post-mortem is neither. It's a rigorous investigation into a system failure. Not "whose fault was it" but "what conditions made this outcome predictable in hindsight?"

The purpose: extract the maximum learning value from a failure so you can prevent recurrence and improve the system.


The Framework

Step 1: Define the Event Precisely

Before analysis: describe exactly what happened.

  • What was the expected outcome?
  • What was the actual outcome?
  • When was the gap first visible?
  • What was the impact (financial, operational, reputational)?

Precision matters. "We missed Q3 revenue" is not precise enough. "We closed $420K in new ARR vs $680K target — a $260K miss driven primarily by three deals that slipped to Q4 and one deal that was lost to a competitor" is precise.

Step 2: The 5 Whys — Done Properly

The goal: get from what happened (the symptom) to why it happened (the root cause).

Standard bad 5 Whys:

  • Why did we miss revenue? Because deals slipped.
  • Why did deals slip? Because the sales cycle was longer than expected.
  • Why? Because the customer buying process is complex.
  • Why? Because we're selling to enterprise.
  • Why? That's just how enterprise sales works.

→ Conclusion: Nothing to do. It's just enterprise.

Real 5 Whys:

  • Why did we miss revenue? Three deals slipped out of quarter.
  • Why did those deals slip? None of them had identified a champion with budget authority.
  • Why did we progress deals without a champion? Our qualification criteria didn't require it.
  • Why didn't our qualification criteria require it? When we built the criteria 8 months ago, we were in SMB, not enterprise.
  • Why haven't we updated qualification criteria as ICP shifted? No owner, no process for criteria review.

Read the full file on GitHub · 194 lines

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. today First seen · 194 lines · 60 tokens per session scan A ca1b7ab332c7

Subscribe to this mod's changes

postmortem is a skill published in the GitHub repository alirezarezvani/claude-skills (28,607 stars, last pushed yesterday), licensed MIT. It adds 60 tokens to every session and 1,758 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-10-24.

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