arch-docs

arch-docs is a skill for Claude Code, Codex from vosslab/vosslab-skills. It costs 53 tokens per session (1,141 once invoked), scanned A, original, MIT.

A documentation procedure for describing a software repository's architecture and file layout. It creates or refreshes docs/CODEARCHITECTURE.md and docs/FILESTRUCTURE.md from the files and configuration that actually exist.

In plain words
What is it for?
Use it to document languages, build tools, entry points, core logic, tests, scripts, and the roles of important folders and files.
Why use it?
It reduces outdated or invented documentation by basing the description on repository evidence and recording unclear areas as follow-up checks.

Skill for Claude CodeCodex

Part of the vosslab-skills plugin — 42 skills, 14 agents 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/vosslab/vosslab-skills/arch-docs
Any agent
npx skills add vosslab/vosslab-skills --skill arch-docs
Clone the repo
git clone --depth 1 https://github.com/vosslab/vosslab-skills

Made for: Claude Code, Codex.

Or install vosslab-skills, the plugin that ships this one along with the rest of its 42 skills, 14 agents.

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 arch-docs

README.md
[![agentmods](https://agentmods.dev/badge/skills/vosslab/vosslab-skills/arch-docs.svg)](https://agentmods.dev/skills/vosslab/vosslab-skills/arch-docs)
Your own site
<a href="https://agentmods.dev/skills/vosslab/vosslab-skills/arch-docs"><img src="https://agentmods.dev/badge/skills/vosslab/vosslab-skills/arch-docs.svg" alt="Measured on agentmods" height="20"></a>
Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,141 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 5.1 $0.00053 $0.01141
Opus 5 $0.00026 $0.00571
Sonnet 5 $0.00011 $0.00228
Haiku 4.5 $0.00005 $0.00114

Measured 5d ago against content hash f5fd5b5aa30b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

arch-docs 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 5d 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/documentation/arch-docs/SKILL.md · 112 lines

How it starts

The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Arch docs

Overview

Create or refresh architecture and file-structure documentation from the current repo state. Base statements on observable files and configs, and record unknowns as verification tasks.

Workflow

  1. Inspect the repo
    • Read README.md and AGENTS.md.
    • Scan layout with ls -1 and ls -1 ./docs/.
    • Use rg --files to get a fuller inventory when needed.
    • Identify languages, build tooling, entry points, and main executables.
    • Check common manifests (pyproject.toml, pip_requirements.txt, package.json, Cargo.toml, go.mod, Makefile) when present.
    • Locate core logic, scripts, and tests.
    • Check .gitignore for generated artifacts and caches.
    • Run git status -suno to see uncommitted changes.
  2. Update policy
    • Remove stale details.
    • Keep accurate sections and restructure for clarity when needed.
    • State facts only; do not invent details.
    • If unclear, add a verification task in the "Known gaps" section.
  3. Apply style and consistency
    • Follow docs/MARKDOWN_STYLE.md and docs/REPO_STYLE.md.
    • Use present tense, concrete paths, and relative links.
    • Link file and folder names to their repo paths when mentioned, so they are clickable for details. Markdown links are created using the syntax [link text](URL), where "link text" is the clickable text that appears in the document, and "URL" is the web address or file path the link points to. This allows users to navigate between different content easily. Use file-path link text so readers know the exact filename (good: [docs/MARKDOWN_STYLE.md](docs/MARKDOWN_STYLE.md), bad: [Style Guide for Markdown](docs/MARKDOWN_STYLE.md)). Only include a backticked path when the link text is not the path.
    • Prefer short, scannable bullets.
    • Only include commands verifiable from repo files.
    • Avoid non-ASCII characters unless explicitly required by existing docs.
    • Prefer ISO-8859-1 only when the repo already uses it.
  4. Write docs/CODE_ARCHITECTURE.md
    • Title: "Code architecture"
    • Sections to include when applicable:
      • Overview
      • Major components (what, where, key dependencies)
      • Data flow (primary use case end-to-end)
      • Testing and verification (only if verifiable)
      • Extension points (where to add code/modules/integrations)
      • Known gaps (verification tasks only)
  5. Write docs/FILE_STRUCTURE.md
    • Title: "File structure"
    • Sections to include when applicable:
      • Top-level layout (key dirs/files with one-line purpose)
      • Key subtrees (large directories that need clarification)
      • Generated artifacts (what/where/git ignored)
      • Documentation map (docs location and root docs)
      • Where to add new work (code/tests/docs/scripts/data)

Read the full file on GitHub · 112 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 112 lines · 53 tokens per session scan A f5fd5b5aa30b

Subscribe to this mod's changes

arch-docs is a skill published in the GitHub repository vosslab/vosslab-skills (2 stars, last pushed 9d ago), licensed MIT. It adds 53 tokens to every session and 1,141 once invoked, about $0.0003 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 2026-08-31.

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