---
title: "arc42"
description: "Generate arc42 architecture documentation from a codebase. Reads the repo into a structured evidence base, then writes the 12 arc42 sections (Mermaid diagrams where the code gives high-confidence structure, explicit GAP "
canonical: https://agentpluginsdirectory.com/plugins/arc42
last-updated: 2026-10-12
---

# arc42
Generate arc42 architecture documentation from a codebase. Reads the repo into a structured evidence base, then writes the 12 arc42 sections (Mermaid diagrams where the code gives high-confidence structure, explicit GAP flags where human input is needed, never fabricated). Knowledge base derived from the arc42 framework under CC BY-SA 4.0.
- Slug: arc42
- Publisher: Florian Buetow
- Repository: https://github.com/florianbuetow/codex-plugins
- Manifest: plugins/arc42/plugin.json
- Version: 0.1.0
- License: CC-BY-SA-4.0
- Category (editorial): other
- Skills: 8 (arc42-framework, consistency-checker, drift-check, evidence-scout, fill-gaps, gap-check, generate, section-author)
- MCP servers: 0
- Stars: 0
- Repository created: 2026-09-10
- Repository last pushed: 2026-10-11
- Publisher type: User
- Listing: https://agentpluginsdirectory.com/plugins/arc42
- Schema: https://agent-plugins.org/schemas/1.0.0/plugin.schema.json

## What arc42 does, in the publisher's words

> Generated for Codex from the canonical source plugin. Run just update at the marketplace root to refresh it.

Generate arc42 architecture documentation from a codebase. Reads the repo into a structured evidence base, then writes the 12 arc42 sections (Mermaid diagrams where the code gives high-confidence structure, explicit GAP flags where human input is needed, never fabricated). Knowledge base derived from the arc42 framework under CC BY-SA 4.0.

Register the repository marketplace with codex plugin marketplace add., then run codex plugin add arc42@florianbuetow-codex-plugins or install it from Florian Buetow Codex Plugins in the Plugins Directory. Invoke its workflows with $.

- Evidence sweep: evidence-scout agent reads source files, configs, manifests, and infrastructure code into a structured _evidence.md base.
- Section authoring: section-author agent writes each of the 12 arc42 sections from evidence only. Claims anchor to source files via comment tags. Content without a source anchor is flagged as.

From the project README, punctuation lightly normalized. Full text: https://raw.githubusercontent.com/florianbuetow/codex-plugins/HEAD/plugins/arc42/README.md