atomic AGENTS.md

Instructions for Atomic, a personal knowledge base that stores free-form Markdown notes and connects related information into an AI-assisted knowledge graph. It describes the software's architecture and the role of its core components and wrappers.

In plain words
What is it for?
Use it when planning or implementing features in the Atomic codebase, including its desktop app and headless HTTP server. It helps explain concepts such as notes, sources, tags, and the processing that happens when a note is created or updated.
Why use it?
It gives a coding agent the project context needed to make changes that fit the existing design. It emphasizes simple, maintainable code for software already used by people worldwide.

Instructions file for CodexOpenCode

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 instructions/kenforthewin/atomic/agents-md
Clone the repo
git clone --depth 1 https://github.com/kenforthewin/atomic

Made for: Codex, OpenCode.

Per session 3,329 This file is loaded in full into every session.
When invoked 3,329 The same file — it is already loaded in full.
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 $0.03329 $0.03329
Opus 5 $0.01665 $0.01665
Sonnet 5 $0.00666 $0.00666
Haiku 4.5 $0.00333 $0.00333

Measured 2d ago against content hash d1762e2bb068, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

atomic AGENTS.md 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 2d 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.

AGENTS.md · 207 lines

How it starts

The opening of the file, as written. The whole thing — 207 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Atomic

Atomic is a personal knowledge base that turns freeform markdown notes ("atoms") into a semantically-connected, AI-augmented knowledge graph. It runs as a Tauri desktop app, a headless HTTP server, or both simultaneously.

You

You are an expert software developer and architect. You plan and implement software designs which are simple, maintainable, and elegant. You choose abstractions that not only solve the problem at hand, but position the codebase for future iteration. You avoid repetition and index heavily on writing code that is easy to understand and extend. You are working in an open source codebase on a project that is currently in use by users all around the world. You will therefore be judged not only by the functional output of your software but by the quality of the code itself. Above all, do not be lazy: take pride in your implementations, and think deeply about the best way to approach problems, not the easiest way. Quality is everything.

Core Concepts

Atoms are the fundamental unit — markdown notes with optional source URLs and hierarchical tags. When an atom is created or updated, an asynchronous pipeline automatically:

  1. Chunks the content using markdown-aware boundaries (respecting code blocks, headers, paragraphs)
  2. Generates vector embeddings via the configured AI provider
  3. Extracts and assigns tags using LLM structured outputs (if auto-tagging is enabled)
  4. Builds semantic edges to other atoms based on embedding similarity

This pipeline is fire-and-forget from the caller's perspective — the caller receives the saved atom immediately while embedding/tagging runs in the background, with progress reported via callbacks.

Tags form a hierarchical tree. Auto-extracted tags are organized under category parents (Topics, People, Locations, Organizations, Events). Tags serve as both organizational structure and scoping mechanism for wiki generation and chat conversations.

Wiki articles are LLM-synthesized summaries of all atoms under a given tag, with inline citations linking back to source atoms. They support incremental updates — when new atoms are tagged, only the new content is sent to the LLM to integrate into the existing article.

Read the full file on GitHub · 207 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. 2d ago First seen · 207 lines · 3,329 tokens per session scan A d1762e2bb068

Subscribe to this mod's changes

atomic AGENTS.md is an instructions file published in the GitHub repository kenforthewin/atomic (1,942 stars, last pushed 23d ago), licensed MIT. It adds 3,329 tokens to every session, about $0.0166 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.