Environment variables, explained
Everything we wish we knew before our first broken deploy. Short, practical, framework-agnostic.
What is a .env file? A developer's guide (2026)
A complete guide to .env files — what they are, how runtimes load them, why they matter, and how to use them safely across Node.js, Next.js, Django, and more.
10 .env best practices every team should follow
Battle-tested rules for .env files: what to commit, what to rotate, how to structure secrets across dev, staging, and production, and the common mistakes that cause outages.
How to use dotenv: Node.js, React, Next.js, Rails, Django, webpack
Every way to load a .env file — dotenv/config, the dotenv CLI, Node's --env-file flag, Create React App, Vite, Next.js, webpack, Django, Rails, Laravel, and Go. Load order and override rules included.
What is NEXT_PUBLIC_ in Next.js env variables?
The NEXT_PUBLIC_ prefix decides whether an env variable is shipped to the browser or kept on the server. Here's how it works, when to use it, and the traps.
Hide .env from git (and recover if committed)
Step-by-step: keep .env out of git from day one, and what to do when a secret leaks into your commit history. Includes rotation checklist.
How to fix .env file errors (complete troubleshooting)
The 12 most common .env file errors — missing values, duplicate keys, bad quotes, encoding issues, case sensitivity — with exact fixes for each.
GitHub Actions Secrets: How to Add, Use & Rotate Them (2026)
Step-by-step: add a secret in Settings → Secrets, reference it with ${{ secrets.NAME }}, keep it masked in logs, and rotate it without breaking a run. Repo vs environment vs org secrets, plus OIDC as a secretless alternative.
Vercel Environment Variables: Setup, Sensitive Vars & CLI (2026)
How to add, pull, and manage environment variables in Vercel. Covers Production vs Preview vs Development, Sensitive environment variables (encrypted, runtime-only), vercel env pull, and the Vercel CLI.