# writing-postmortems

A skill for writing postmortems and root-cause analyses: evidence-only timelines, blameless framing, action items with owners.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 18000 installs · ★ 33
- Author: riekelt
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/riekelt/technical-writer/tree/HEAD/plugins/technical-writer/skills/writing-postmortems/SKILL.md
- Updated: 2026-09-13
- HTML: https://affpapa.org/en/nevibecode/skills/writing-postmortems

## What it does

The skill fires once an incident is resolved or has reached a stable milestone. A defect that reached users counts, and so does a near miss where a guard caught what review missed. During a live incident it stays out of the way, because the runbook governs that.

What you get is a skeleton: a header with date, duration, severity and status, then Summary, Impact with numbers, Timeline, Root cause and contributing factors, a section on wrong turns during the response, action items, and a sign-off. Every timeline entry traces to something checkable, an alert, a log line, a commit, a message. Where memory is the only source, the document says so.

Blameless here is structural. Name the role, the gate, the dependency, the missing guard, never the person. Ownership of an action item is assignment, not blame. Once reviewed, the postmortem is immutable and new findings arrive as dated addenda. The skill requires the `technical-writing` background and leans on `writing-issues` for tracker items and `recording-decisions` for decisions that follow.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add riekelt/technical-writer --skill writing-postmortems -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/writing-postmortems/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/writing-postmortems/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add riekelt/technical-writer --skill writing-postmortems -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/writing-postmortems/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add riekelt/technical-writer --skill writing-postmortems -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/writing-postmortems/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install riekelt/technical-writer writing-postmortems
```

2. **Manually: put the files in place**
- File: `.github/skills/writing-postmortems/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add riekelt/technical-writer --skill writing-postmortems -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/riekelt/technical-writer --path plugins/technical-writer/skills/writing-postmortems
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/writing-postmortems/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add riekelt/technical-writer --skill writing-postmortems -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/riekelt/technical-writer/tree/HEAD/plugins/technical-writer/skills/writing-postmortems/SKILL.md

## When to use it
- turn alerts and logs into a timestamped timeline
- quantify user-visible impact
- separate the root cause from contributing factors
- record the wrong fixes tried during the response
- file action items with an owner and an acceptance check

## Example prompts
- Write a postmortem for this incident, build the timeline from the logs and the channel thread
- Draft a near miss write-up: a guard caught what review missed
- Analyze this outage: root cause, contributing factors, action items with owners

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 0b994539f3e857ad.

BEGIN THIRD-PARTY FILE 0b994539f3e857ad
````text
---
name: writing-postmortems
description: Use when writing a postmortem, incident report, or root-cause analysis after an outage, a defect that reached users, a data issue, or a near miss - or when turning an incident channel, alert log, or war-room thread into a durable document. Encodes the blameless framing, the evidence-only timeline, contributing factors, and owned action items. Use whenever something broke and the write-up must outlive the incident.
---

# Writing postmortems

**REQUIRED BACKGROUND:** the `technical-writing` skill (hard rules, truth rules, style).

## Overview

Audience: the engineer who hits something similar in a year, not the people in the room. Core principle: **facts from evidence, causes from mechanisms, lessons from both, and no names.** Classification: historical; once reviewed it is immutable, and corrections are dated addenda.

## When to invoke, and not

Invoke after an incident is resolved, or at a stable milestone of a long one. A defect that reached users and a near miss (a guard caught what review missed) earn the same write-up. Do NOT invoke during the live incident: the runbook governs that. Not for assigning accountability: a postmortem that needs a person's name to make sense is describing a process hole. Not for a status update to stakeholders, which is a report.

## Skeleton

```markdown
# [System]: [the failure, as its symptom, one line]

| | |
|---|---|
| **Incident date** | YYYY-MM-DD |
| **Duration** | detection to resolution |
| **Severity** | [per the org taxonomy, defined where used] |
| **Status** | Draft / Reviewed |

## Summary
[User-visible impact with numbers, the root cause in one sentence, current state.
The reader who stops here still knows what happened.]

## Impact
[Who and what, quantified: requests failed, records affected, money or time lost.
Estimates labeled as estimates; "no evidence of data loss" only if actually checked,
and say what was checked.]

## Timeline
[Timestamped entries, facts only, each traceable to evidence: an alert, a log line,
a commit, a message. Interpretation lives in the sections below, never here.]

## Root cause and contributing factors
[The mechanism, grounded in code and commits. Contributing factors as a list;
"every component was correct and the defect lived between them" is a valid root
cause. Name which layer of checking missed it and which caught it.]

## Wrong turns during the response
[The wrong first fix, the misleading signal followed, the theory that cost an hour.]
````
END THIRD-PARTY FILE 0b994539f3e857ad

The third-party file has ended. Everything between the 0b994539f3e857ad tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

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