# 12 Factor Apps

Perform 12-Factor App compliance analysis on any codebase.

- Repository: https://github.com/LeoYeAI/agent-master-skills (2171 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add LeoYeAI/agent-master-skills --skill 12-factor-apps -g -a claude-code -y`
Codex: `npx skills add LeoYeAI/agent-master-skills --skill 12-factor-apps -g -a codex -y`
Cursor: `npx skills add LeoYeAI/agent-master-skills --skill 12-factor-apps -g -a cursor -y`
Gemini CLI: `npx skills add LeoYeAI/agent-master-skills --skill 12-factor-apps -g -a gemini-cli -y`

## Description

Perform 12-Factor App compliance analysis on any codebase. Use when evaluating application architecture, auditing SaaS applications, or reviewing cloud-native applications against the original 12-Factor methodology.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# 12-Factor App Compliance Analysis

> Reference: [The Twelve-Factor App](https://12factor.net)

## Overview

The 12-Factor App methodology is a set of best practices for building Software-as-a-Service applications that are:
- Portable across execution environments
- Scalable without architectural changes
- Suitable for continuous deployment
- Maintainable with minimal friction

## Input Parameters

| Parameter | Description | Required |
|-----------|-------------|----------|
| `codebase_path` | Root path of the codebase to analyze | Required |

## Analysis Framework

### Factor I: Codebase

**Principle:** One codebase tracked in revision control, many deploys.

**Search Patterns:**
```bash
# Check for version control
ls -la .git 2>/dev/null || ls -la .hg 2>/dev/null

# Check for multiple apps sharing codebase
find . -name "package.json" -o -name "pyproject.toml" -o -name "setup.py" | head -20

# Check for environment-specific code branches
grep -r "if.*production\|if.*development\|if.*staging" --include="*.py" --include="*.js" --include="*.ts"
```

**File Patterns:** `.git/`, `package.json`, `pyproject.toml`, deployment configs

**Compliance Criteria:**

| Level | Criteria |
|-------|----------|
| **Strong** | Single Git repo, same codebase for all environments, no env-specific code branches |
| **Partial** | Single repo but some environment-specific code paths |
| **Weak** | Multiple repos for same app or significant code duplication across environments |

**Anti-patterns:**
- Multiple Git repositories for the same application
- Environment-specific code branches (`if production: ...`)
- Different source files for dev vs prod
- Shared code not extracted to libraries

---

### Factor II: Dependencies

**Principle:** Explicitly declare and isolate dependencies.

**Search Patterns:**
```bash
# Python dependency files
find . -name "requirements.txt" -o -name "pyproject.toml" -o -name "setup.py" -o -name "Pipfile" -o -name "uv.lock"

The rest: https://github.com/LeoYeAI/agent-master-skills/blob/HEAD/skills/12-factor-apps/SKILL.md