A5N — AI skill for Claude Code

A5N

Turn your AI coding agent transcripts into a knowledge base that outlives them.

A5N is a numeronym for AIBrain, the way k8s abbreviates Kubernetes: first letter, five letters, last letter.

[Türkçe](README.tr.md)

The problem

Claude Code and Codex write every session to disk, then delete it. Claude Code clears transcripts after `cleanupPeriodDays`, thirty days by default. So the reasoning behind a decision you made six weeks ago, the root cause of a bug you already fixed once, the reason you rejected the obvious approach, all of it is gone. You keep solving the same problem, and your agent keeps proposing the approach you already rejected, because neither of you can remember.

What A5N does

Every morning a deterministic script finds yesterday's sessions and copies the raw transcripts somewhere permanent. Then one headless agent per session distils it into a linked markdown wiki: one page per session, plus pages for the decisions, bugs, entities and concepts it touches. Once a week the same machinery audits that wiki for contradictions, dead links and schema drift.

The output is plain markdown in a git repository. Obsidian is a nice way to browse it and is entirely optional. Nothing is stored anywhere but your disk.


The most valuable folder is `patterns/`. When a lesson is not tied to one project, it gets its own page there, and your next project finds it. That is what turns a pile of notes into knowledge that keeps growing in value.

See [example/](example/) for four pages of invented output, and [the pattern page](example/patterns-example/retry-without-a-budget-amplifies-an-outage.md) for what the system is actually for.

What the vault looks like

Plain folders, plain markdown. Every project you configure gets its own namespace, and a handful of folders live at the root:

vault/
├── /             one namespace per configured project
│   ├── sources/sessions/  one page per processed sessio