postmortem-aggregator

postmortem-aggregator is a skill for Claude Code, Codex from gemini-cli-extensions/sre. It costs 45 tokens per session (973 once invoked), scanned A, original, Apache-2.0.

A tool for comparing multiple postmortem files, where a postmortem records a service outage and its causes. It extracts common incident details and maintains an aggregated Markdown report and statistics file.

In plain words
What is it for?
Analyzing folders with at least two postmortems, recording outage timestamps and causes in CSV form, and updating a combined summary.
Why use it?
It turns several separate incident reports into comparable data, making recurring causes, outage sizes, and response times easier to review.

Skill for Claude CodeCodex

Part of the sre plugin — 16 skills shipped together

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.

agentmods
npx agentmods add skills/gemini-cli-extensions/sre/postmortem-aggregator
Any agent
npx skills add gemini-cli-extensions/sre --skill postmortem-aggregator
Clone the repo
git clone --depth 1 https://github.com/gemini-cli-extensions/sre

Made for: Claude Code, Codex.

Or install sre, the plugin that ships this one along with the rest of its 16 skills.

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-aggregator

README.md
[![agentmods](https://agentmods.dev/badge/skills/gemini-cli-extensions/sre/postmortem-aggregator.svg)](https://agentmods.dev/skills/gemini-cli-extensions/sre/postmortem-aggregator)
Your own site
<a href="https://agentmods.dev/skills/gemini-cli-extensions/sre/postmortem-aggregator"><img src="https://agentmods.dev/badge/skills/gemini-cli-extensions/sre/postmortem-aggregator.svg" alt="Measured on agentmods" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 973 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00045 $0.00973
Opus 5 $0.00023 $0.00487
Sonnet 5 $0.00009 $0.00195
Haiku 4.5 $0.00005 $0.00097

Measured 4d ago against content hash bb1d3664a918, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

postmortem-aggregator 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 4d 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.

skills/postmortem-aggregator/SKILL.md · 68 lines

How it starts

The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Identify the PoMos

  • If the pomos are local in a folder, use those.
  • If they're external, create a new folder called YYYYMMDD_POSTMORTEMS/ and copy their MD version there. This might lose information, but ensure the relevant info is transported here, locally. You could run the "postmortem generator" skill on a locally curled page.
  • If there is ONE, refuse to run this.
  • If there is 2-3, suggest the user it's worth using a plurality of these.

Action

Check all the Post Mortems in the folder and identify these informations:

  1. Timestamp of outage start.
  2. Timestamp of outage identified by human and being worked on (if available).
  3. Timestamp of first Mitigation going into place (if available)
  4. Timestamp of outage end.
  5. Product used (eg Cloud, Youtube). Products could have a taxonomy (eg Cloud::GCE::PersistentDisk, Youtube::Playlists)
  6. RootCause class (HUMAN_ERROR, CONFIG_CHANGE, EXTERNAL_CAUSE, ..).
  7. Outage size, how bad it was (TEST, NEGLIGIBLE, SMALL, MEDIUM, BIG, CATASTROPHIC).

Build a pomo_stats.csv with this data, one line per incident

filename,title,outage_start,outage_detected,outage_mitigated,outage_ended,root_cause,size
folder/20260101-millennium-bug.md,Millennium Bug hit us!,20260101-09:00:00,,,20260101-12:42:00,HUMAN_ERROR,NEGLIGIBLE

Crunching the data

Once you have the CSV with raw data, you can write some simple code which does the following:

  1. Decide what YOUR_DESIGNATED_FOLDER is.
  2. Create or Update POMO_AGGREGATED.md under YOUR_DESIGNATED_FOLDER/.
  3. Caculate for every incident:
    • outage_duration (end - start)
    • time_to_detect (detect - start)
    • time_to_mitigate (mitigate - detect).
    • detection_rate (ratio between time_to_detect / outage_duration ). This is indicative of how fast we're to OBSERVE an outage vs FIX it and tells us a lot about our organization.
  4. Do an aggregation of all stats except detection_rate (its a percentage on varying numbers, so it's comparing watermellons to cherries).
  5. Do a subjective analysis of the detection_rate.
  6. Create breakdown by YEAR and PRODUCT.
  7. Consider using image generation scripts to create simple graphs.

Read the full file on GitHub · 68 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. 4d ago First seen · 68 lines · 45 tokens per session scan A bb1d3664a918

Subscribe to this mod's changes

postmortem-aggregator is a skill published in the GitHub repository gemini-cli-extensions/sre (82 stars, last pushed 10d ago), licensed Apache-2.0. It adds 45 tokens to every session and 973 once invoked, about $0.0002 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 2026-08-30.

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