Dotenv Inheritance Mapper

Every project accumulates .env files: .env, .env.local, .env.example, .env.staging, .env.production, .env.test. They override each other in framework-specific order that nobody remembers. When a bug is "only in staging", it's usually a variable that exists in one file and not another.

This skill resolves your full .env chain into a single merged view — showing exactly which layer each value comes from, what overrides what, and where the gaps are.

No external API. No config. Works for Next.js, Vite, Create React App, NestJS, FastAPI, Rails, or any custom setup.

Trigger Phrases

• "env inheritance", "which .env file wins", "env override order"
• "merge my env files", "what's the effective value of X"
• "missing from .env.example", "env files conflict"
• "env chain", "dotenv hierarchy", ".env resolution order"
• "/dotenv-mapper"