agent-rules-books is an MIT-licensed, tool-agnostic collection of AGENTS.md rules and agent skills, distilled from classic software engineering books, that installs into AI coding agents such as Codex, Cursor and Claude Code to steer them toward better refactoring, architecture, domain-driven design and code quality.

What it is

The project provides ready-to-use rule sets for coding agents, each one derived from a well-known book on software design, architecture, refactoring, legacy code, reliability or data-intensive systems. Covered titles include Clean Code, Clean Architecture, Code Complete, Refactoring, Domain-Driven Design, Designing Data-Intensive Applications and A Philosophy of Software Design. Every rule set ships in three tool-agnostic Markdown versions: mini, described as the recommended version for most real task use; nano, a compact fallback for very tight context budgets; and full, the canonical complete source and reference version. Each book directory contains a standard SKILL.md entrypoint that loads the mini rule set by default while keeping the full file available as deeper reference material.

The concrete problem it solves is the blank page that greets anyone writing agent instructions. Instead of hand-authoring project rules and hoping they capture decades of accumulated engineering judgement, a user installs curated rule sets that already encode the practices from these books. It lives in the emerging agent skills and AGENTS.md ecosystem, alongside the open Agent Skills CLI, and it replaces the ad hoc, self-written rule files that teams otherwise maintain separately for Codex, Cursor and Claude Code. The rules are deliberately tool-agnostic Markdown, which is what lets a single source serve all three editors.

Key capabilities

• Three release tiers per book — mini, nano and full — so the same rule set scales from recommended everyday use down to very tight context budgets.
• A standard SKILL.md entrypoint in every book directory, allowing installation through the open Agent Skills CLI.
• Skills CLI commands for bulk and selective installs: npx skills add ciembor/agent-rules-books --all, --list to preview without installing, and --skill refactoring to install a single rule set.
• docs/USAGE.md documents always-on versus on-demand usage, skills, scoped rules and the preferred setup for each of Codex, Claude Code and Cursor.
• A release matrix reporting deterministic metrics per rule set, including line counts from wc -l, rule counts from a fixed counting convention, and raw byte sizes from wc -c.
• Rule sets spanning refactoring, code quality, clean architecture, domain-driven design and data-intensive systems.
• CRITICISM.md collects constructive criticism from Reddit, and CHANGELOG.md records release history, with the current line at v0.6.

Who uses it and how

• Teams running more than one AI coding agent, using a shared Markdown rule source so Codex, Cursor and Claude Code behave consistently.
• Developers working under tight context limits, who install the nano version instead of the recommended mini one.
• Engineers doing refactoring or legacy-code work, who install the targeted refactoring skill rather than the whole collection.
• Architects and domain-modelling practitioners applying the Clean Architecture and Domain-Driven Design rule sets as always-on or scoped rules.
• Contributors who read CRITICISM.md before adopting, and track changes through CHANGELOG.md.

Getting started

Install Node.js with npm, then install every book skill with npx skills add ciembor/agent-rules-books --all; skills itself does not need separate installation. For editor-specific, manual or scoped setups, follow docs/USAGE.md.

How it compares

No list of paid products this project replaces is provided in the facts, and no directly comparable tool is named, so it stands alone in this registry. What the facts do establish is its position across three agent ecosystems at once — Codex, Cursor and Claude Code — served from one MIT-licensed Markdown source rather than per-editor rule formats.

When to use it — and when not to

There is nothing to operate: no database, storage layer or SMTP service is mentioned, because the deliverable is Markdown plus a Node.js-based CLI install. It is a poor fit for anyone expecting a hosted product, and the rule sets are distilled summaries of the source books rather than replacements for reading them. The facts also show that a CRITICISM.md file exists, which signals the maintainers consider the rule sets debatable rather than settled.

npx skills add ciembor/agent-rules-books --all

npx skills add ciembor/agent-rules-books --list

npx skills add ciembor/agent-rules-books --skill refactoring