# Configuration Management

> Manage application and infrastructure configuration cleanly across environments with clear ownership and safe defaults. Use when dealing with environment-specific settings, feature toggles, or configuration sprawl.

- Skill: `itsual/configuration-management` (Agent Skill)
- Install (CLI): `npx skillmds@latest add itsual/configuration-management`
- Raw SKILL.md: https://api.skillmd.com/api/skills/itsual/configuration-management/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: itsual (https://skillmd.com/u/itsual)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/itsual/configuration-management

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# Configuration Management

## Overview

Configuration is code’s quieter sibling. Poor configuration practices cause environment drift, outages, and security issues.

## When to Use

- Setting up new services or environments
- Dealing with “works on my machine” / environment drift
- Managing feature flags, defaults, and overrides

## Principles

- Keep configuration separate from code
- Make configuration explicit and documented
- Prefer safe defaults
- Avoid scattering the same setting in many places
- Support progressive delivery and per-environment overrides cleanly
- Validate configuration at startup when possible

## Practices

- 12-factor style config via environment or mounted secrets/config
- Typed configuration objects
- Clear precedence rules (defaults < env < explicit overrides)
- Auditability of changes in production config

## Verification

- Configuration required for startup is validated
- Differences between environments are intentional and documented
- Sensitive config is handled via secrets management