Post Mortem
thananon/9arm-skills
Write the canonical engineering record of a fixed bug — root cause, mechanism, fix, validation, and how it slipped through.
/em:postmortem — Honest analysis of what went wrong. An agent skill from alirezarezvani/claude-skills.
Install Postmortem
$ npx skills add alirezarezvani/claude-skills --skill postmortem -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install alirezarezvani/claude-skills postmortem --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/alirezarezvani/claude-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/c-level-advisor/executive-mentor/skills/postmortem .claude/skills/postmortem && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "postmortem" agent skill from https://github.com/alirezarezvani/claude-skills/tree/main/c-level-advisor/executive-mentor/skills/postmortem into .claude/skills/postmortem/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "postmortem", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/alirezarezvani/claude-skills/tree/main/c-level-advisor/executive-mentor/skills/postmortemType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add alirezarezvani/claude-skills --skill postmortem -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install alirezarezvani/claude-skills postmortem --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/alirezarezvani/claude-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/c-level-advisor/executive-mentor/skills/postmortem .agents/skills/postmortem && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "postmortem" agent skill from https://github.com/alirezarezvani/claude-skills/tree/main/c-level-advisor/executive-mentor/skills/postmortem into .agents/skills/postmortem/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "postmortem", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add alirezarezvani/claude-skills --skill postmortem -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install alirezarezvani/claude-skills postmortem --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/alirezarezvani/claude-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/c-level-advisor/executive-mentor/skills/postmortem .cursor/skills/postmortem && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "postmortem" agent skill from https://github.com/alirezarezvani/claude-skills/tree/main/c-level-advisor/executive-mentor/skills/postmortem into .cursor/skills/postmortem/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "postmortem", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/alirezarezvani/claude-skills.git --path c-level-advisor/executive-mentor/skills/postmortem--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add alirezarezvani/claude-skills --skill postmortem -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install alirezarezvani/claude-skills postmortem --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/alirezarezvani/claude-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/c-level-advisor/executive-mentor/skills/postmortem .gemini/skills/postmortem && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "postmortem" agent skill from https://github.com/alirezarezvani/claude-skills/tree/main/c-level-advisor/executive-mentor/skills/postmortem into .gemini/skills/postmortem/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "postmortem", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install alirezarezvani/claude-skills postmortemInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add alirezarezvani/claude-skills --skill postmortem -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/alirezarezvani/claude-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/c-level-advisor/executive-mentor/skills/postmortem .github/skills/postmortem && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "postmortem" agent skill from https://github.com/alirezarezvani/claude-skills/tree/main/c-level-advisor/executive-mentor/skills/postmortem into .github/skills/postmortem/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "postmortem", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add alirezarezvani/claude-skills --skill postmortem -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install alirezarezvani/claude-skills postmortem --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/alirezarezvani/claude-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/c-level-advisor/executive-mentor/skills/postmortem .opencode/skills/postmortem && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "postmortem" agent skill from https://github.com/alirezarezvani/claude-skills/tree/main/c-level-advisor/executive-mentor/skills/postmortem into .opencode/skills/postmortem/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "postmortem", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
postmortem- GitHub stars
- 28k
- Used in
- 2 other repos
- Token cost
- ~2k tokens
- SKILL.md length
- 1,027 words
- Files
- 1
- Skills in repo
- 342
- Repo updated
- First seen
- Licence
- MIT
At a glance
/em:postmortem — Honest analysis of what went wrong. An agent skill from alirezarezvani/claude-skills.
- Works in 7 steps: Define the Event Precisely → The 5 Whys — Done Properly → Distinguish Contributing Factors from… → …
- Tasks that involve Runbooks and postmortems
- SKILL.md covers Why Most Post-Mortems Fail, The Framework, Post-Mortem Output Format and The Tone of Good Post-Mortems
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Postmortem is an agent skill from alirezarezvani/claude-skills. /em:postmortem — Honest analysis of what went wrong. Use after a failed launch, missed quarter, or bad hire to run a blameless 5-Whys retrospective with a change register — e.g. dissecting why the Q3 release slipped six weeks.
Its SKILL.md is about 2k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in DevOps & Cloud, covering Runbooks and postmortems and Root cause analysis. The repository describes itself as: 380 Claude Code skills & agent skills & plugins (30+ Agents, 70+ custom commands, 380+ skills, customizable references, scripts)for Claude Code, Codex, Gemini CLI, Cursor, and 8… The licence is MIT.
When your agent uses it
- Tasks that involve Runbooks and postmortems
- Tasks that involve Root cause analysis
Example prompts
- “/postmortem”
Workflow steps
7 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 19392f7. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Postmortem loads about 2k tokens when it runs. Until then it costs about 59 tokens; SKILL.md has 1,027 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from alirezarezvani/claude-skills at commit 19392f7, republished under its MIT licence (© alirezarezvani). 1,027 words, ~1,989 tokens.
Download SKILL.mdSave it as
.claude/skills/postmortem/SKILL.md (or your agent's skills folder).- name
- postmortem
- description
- /em:postmortem — Honest analysis of what went wrong. Use after a failed launch, missed quarter, or bad hire to run a blameless 5-Whys retrospective with a change register — e.g. dissecting why the Q3 release slipped six weeks.
/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.
→ Root cause: Qualification criteria outdated, no owner, no review process. → Fix: Update criteria, assign owner, add quarterly review.
The test for a good root cause: Could you prevent recurrence with a specific, concrete change? If yes, you've found something real.
Step 3: Distinguish Contributing Factors from Root Cause
Most events have multiple contributing factors. Not all are root causes.
Contributing factor: Made it worse, but isn't the core reason. If removed, the outcome might have been different — but the same class of problem would recur.
Root cause: The fundamental condition that made the outcome probable. Fix this, and this class of problem doesn't recur.
Example — failed hire:
- Contributing factors: rushed process, reference checks skipped, team under pressure to staff up
- Root cause: No defined competency framework, so interview process varied by who happened to conduct interviews
The distinction matters. If you address only contributing factors, you'll have a different-looking but structurally identical failure next time.
Step 4: Identify the Warning Signs That Were Ignored
Every failure has precursors. In hindsight, they're obvious. The value of this step is making them obvious prospectively.
Ask:
- At what point was the negative outcome predictable?
- What signals were visible at that point?
- Who saw them? What happened when they raised them?
- Why weren't they acted on?
Common patterns:
- Signal was raised but dismissed by a senior person
- Signal wasn't raised because nobody felt safe saying it
- Signal was seen but no one had clear ownership to act on it
- Data was available but nobody was looking at it
- The team was too optimistic to take negative signals seriously
This step is particularly important for systemic issues — "we didn't feel safe raising the concern" is a much deeper root cause than "the deal qualification was off."
Show full SKILL.md (360 more words)Show less
Step 5: Distinguish What Was in Control vs. Out of Control
Some failures happen despite correct decisions. Some happen because of incorrect decisions. Knowing the difference prevents both overcorrection and undercorrection.
- In control: Process, criteria, team capability, resource allocation, decisions made
- Out of control: Market conditions, customer decisions, competitor actions, macro events
For things out of control: what can be done to be more resilient to similar events? For things in control: what specifically needs to change?
Warning: "It was outside our control" is sometimes used to avoid accountability. Be rigorous.
Step 6: Build the Change Register
Every post-mortem ends with a change register — specific commitments, owned and dated.
Bad action items:
- "We'll improve our qualification process"
- "Communication will be better"
- "We'll be more rigorous about forecasting"
Good action items:
- "Ravi owns rewriting qualification criteria by March 15 to include champion identification as hard requirement. New criteria reviewed in weekly sales standup starting March 22."
- "By March 10, Elena adds deal-slippage risk flag to CRM for any open opportunity >60 days without a product demo"
- "Maria runs a 30-min retrospective with enterprise sales team every 6 weeks starting April 1, reviews win/loss data"
For each action:
- What exactly is changing?
- Who owns it?
- By when?
- How will you verify it worked?
Step 7: Verification Date
The most commonly skipped step. Post-mortems are useless if nobody checks whether the changes actually happened and actually worked.
Set a verification date: "We'll review whether qualification criteria have been updated and whether deal slippage rate has improved at the June board meeting."
Without this, post-mortems are theater.
Post-Mortem Output Format
EVENT: [Name and date]
EXPECTED: [What was supposed to happen]
ACTUAL: [What happened]
IMPACT: [Quantified]
TIMELINE
[Date]: [What happened or was visible]
[Date]: ...
5 WHYS
1. [Why did X happen?] → Because [Y]
2. [Why did Y happen?] → Because [Z]
3. [Why did Z happen?] → Because [A]
4. [Why did A happen?] → Because [B]
5. [Why did B happen?] → Because [ROOT CAUSE]
ROOT CAUSE: [One clear sentence]
CONTRIBUTING FACTORS
• [Factor] — how it contributed
• [Factor] — how it contributed
WARNING SIGNS MISSED
• [Signal visible at what date] — why it wasn't acted on
WHAT WAS IN CONTROL: [List]
WHAT WASN'T: [List]
CHANGE REGISTER
| Action | Owner | Due Date | Verification |
|--------|-------|----------|-------------|
| [Specific change] | [Name] | [Date] | [How to verify] |
VERIFICATION DATE: [Date of check-in]The Tone of Good Post-Mortems
Blame is cheap. Understanding is hard.
The goal isn't to establish that someone made a mistake. The goal is to understand why the system produced that outcome — so the system can be improved.
"The salesperson didn't qualify the deal properly" is blame. "Our qualification framework hadn't been updated when we moved upmarket, and no one owned keeping it current" is understanding.
The first version fires or shames someone. The second version builds a more resilient organization.
Both might be true simultaneously. The distinction is: which one actually prevents recurrence?
© alirezarezvani, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in c-level-advisor/executive-mentor/skills/postmortem of alirezarezvani/claude-skills.
Open the folder on GitHubat commit 19392f7
Used in 2 other repositories
We found 3 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 2 other GitHub owners. This page covers the copy in alirezarezvani/claude-skills, which our catalogue first saw on October 7, 2026.
Compare with similar skills
Postmortem next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Postmortem this skillalirezarezvani/claude-skills | 28k | 2 repos | ~2k | Automated safety check: Pass | MIT | |
| Post Mortemthananon/9arm-skills | 3.2k | — | ~3.4k | Automated safety check: Pass | None | |
| Post-Incident DebriefVeryGoodOpenSource/vgv-wingspan | 109 | — | ~1.9k | Automated safety check: Pass | MIT | |
| Postmortemdralgorhythm/claude-agentic-framework | 125 | — | ~708 | Automated safety check: Pass | None | |
| Conducting Post Incident Lessons Learnedmukul975/Anthropic-Cybersecurity-Skills | 34k | — | ~1.7k | Automated safety check: Pass | Apache-2.0 | |
| Incident Postmortemgithub/awesome-copilot | 40k | — | ~1.8k | Automated safety check: Pass | MIT |
Similar skills
Post-Incident Debrief
VeryGoodOpenSource/vgv-wingspan
Produces a blameless post-incident debrief with timeline, root cause and follow-up actions after an outage, failed release or significant bug, while details are fresh.
Postmortem
dralgorhythm/claude-agentic-framework
Runs this framework's blameless postmortem workflow — reconstruct the incident timeline from evidence, drive five-whys to a mechanism-level root cause, and produce owner-and-due-date action items…
Conducting Post Incident Lessons Learned
mukul975/Anthropic-Cybersecurity-Skills
Facilitate structured post-incident reviews to identify root causes, document what worked and failed, and produce actionable recommendations to improve future incident response.
- Official
Incident Postmortem
github/awesome-copilot
A skill your agent uses when an outage, production incident, or significant service degradation has occurred and the team needs to write a structured blameless post-mortem.
Quality Postmortem
petrkindlmann/qa-skills
Analyze escaped defects and test suite health through blameless postmortems.
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Questions about Postmortem
What does Postmortem do?
/em:postmortem — Honest analysis of what went wrong. An agent skill from alirezarezvani/claude-skills. Postmortem is an agent skill from alirezarezvani/claude-skills. /em:postmortem — Honest analysis of what went wrong.
When should I use Postmortem?
Postmortem fits situations like: tasks that involve Runbooks and postmortems; tasks that involve Root cause analysis.
How do I install Postmortem in Claude Code?
Run `npx skills add alirezarezvani/claude-skills --skill postmortem -a claude-code`. Or copy the skill folder (c-level-advisor/executive-mentor/skills/postmortem in alirezarezvani/claude-skills) into .claude/skills/postmortem in your project. Claude Code loads it when a task matches its description.
How do I install Postmortem in Codex?
Run `npx skills add alirezarezvani/claude-skills --skill postmortem -a codex`. Or copy the skill folder (c-level-advisor/executive-mentor/skills/postmortem in alirezarezvani/claude-skills) into .agents/skills/postmortem in your project. Codex loads it when a task matches its description.
Can I use Postmortem in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add alirezarezvani/claude-skills --skill postmortem -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/postmortem, .gemini/skills/postmortem, .github/skills/postmortem and .opencode/skills/postmortem in your project.
What does Postmortem need to run?
SKILL.md names no scripts, command-line tools or credentials: Postmortem is instructions for the agent only.
Does Postmortem access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Postmortem safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Postmortem use?
Postmortem is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Postmortem use?
About 2k tokens (SKILL.md is roughly 8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Postmortem?
Skills that share tags, products or a category with Postmortem: Post Mortem (thananon/9arm-skills, 3.2k stars), Post-Incident Debrief (VeryGoodOpenSource/vgv-wingspan, 109 stars), Postmortem (dralgorhythm/claude-agentic-framework, 125 stars) and Conducting Post Incident Lessons Learned (mukul975/Anthropic-Cybersecurity-Skills, 34k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Postmortem?
alirezarezvani (a GitHub user) maintains it in alirezarezvani/claude-skills, which has 27,829 GitHub stars. The repository holds 342 skills in this directory. The repository was last updated on August 30, 2026.
Source: alirezarezvani/claude-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.