envcheck
Overview
Missing or malformed environment variables crash apps at runtime — silently and late. envcheck reads the .env.example schema your team already keeps and checks the real .env against it before the app boots, with type and format hints (number, url, email, oneof, min-length) declared right in the example file’s comments.
The Challenge
A single missing or mistyped env var can take down a deploy, and the failure usually surfaces deep in the stack with a cryptic error nobody can place.
Our Solution
A ~150-line, zero-dependency CLI that treats .env.example as the source of truth: it flags missing keys, empty required values, type mismatches, and orphans, then exits non-zero so CI catches it.
Results
Runs anywhere with npx — no config, no dependencies. Drop it into any Node project or CI pipeline in a single line.