First Principles

First Principles is an AI Engineering skill for Claude Code, published by tjboudreaux in cc-thinking-skills.

969 stars133 forkson tjboudreaux/cc-thinking-skillsAdded 2026/08/21+1% in starsRepository updated 2026/08/07

agent-skillsai-toolsanthropicclaudeclaude-codecritical-thinkingdecision-makingfirst-principlesmental-modelsproblem-solvingsystems-thinking

Install in seconds

Install First Principles

Copy First Principles into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/tjboudreaux/cc-thinking-skills/tree/main/skills/thinking-first-principles ~/.claude/skills/thinking-first-principles

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/tjboudreaux/cc-thinking-skills.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: skills/thinking-first-principles/SKILL.md in tjboudreaux/cc-thinking-skills
Installs to: ~/.claude/skills/thinking-first-principles
Collection: One of 25 skills cataloged from this repository
Category: AI Engineering — 2451 skills

What First Principles does

First Principles strips unsupported assumptions from a problem, keeps only independently supported constraints, and rebuilds the simplest solution. Use it when a limit seems fixed by convention, pricing, or precedent instead of physics or measured need.

First Principles is cataloged under AI Engineering on DirSkills. First Principles comes from a repository tagged agent-skills, ai-tools, anthropic, claude and claude-code.

Documentation

README

Excerpt

First Principles

Strip assumed constraints to independently supported primitives, then rebuild. Escape analogy when convention fails or looks artificially expensive.

When to Use

A constraint is treated as fixed ("too expensive," "impossible," "always done this way") without independent support.
Convention or analogy has failed, stalled, or only yields weak incremental variants.
Greenfield design where industry defaults may smuggle false requirements.
Cost or feasibility claims rest on pricing, precedent, or authority rather than physics, math, or measured need.

When NOT to Use

This is the opening of the README. Read the full README on GitHub.

Frequently asked about First Principles

What else does tjboudreaux publish alongside First Principles?
First Principles is one of 25 skills that DirSkills catalogs from tjboudreaux/cc-thinking-skills, the repository it ships in. Its siblings there include Bounded Rationality, Circle Of Competence and Effectuation. Each one is a separate skill with its own page in this directory, installs the same way First Principles does, and is maintained by tjboudreaux in that same repository. The rest of the collection is listed on the tjboudreaux/cc-thinking-skills page.
How does First Principles compare to other AI Engineering skills?
First Principles ranks #1392 by stars among the 2451 AI Engineering skills in this catalog. The most-starred ones next to it are Architecture Decision Records, AI-First Engineering and Agentic OS. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of First Principles against them. Open each page to compare what they document and how they install.