Env File Diff & Validator CLI
Compare .env files across local, staging and production and validate them against a schema in CI, without ever printing secret values.
Economics
- Pricing example
- $15 personal licence; $49 team licence (free version: diff only)
- Daily math
- 1 personal + 1 team sale every 3 days = $64 / 3 = about $21/day.
- Target if you hit the daily math
- Target: $500 - $750 / month if the daily math is hit
Audience and urgency
Audience: Developers and small teams deploying apps across several environments with environment variables.
Urgency: A missing or misnamed environment variable is a common cause of broken deploys, and it often shows up only in production. Comparing env files by eye is error-prone and risks pasting secrets into chat.
MVP scope
- ✓ Diff command: keys missing or extra between .env.example and any other env file, values never printed
- ✓ Schema file (env.schema.json) with type, required, enum, URL, number range and regex rules
- ✓ CI mode with non-zero exit codes and a GitHub Action wrapper
- ✓ Warning when an example file contains values that look like real secrets
- ✓ Licence key check for paid features (schema validation and CI mode), offline-friendly
Omitted features
- - Do NOT store or upload env values anywhere
- - Do NOT build a hosted secrets manager
- - Do NOT add cloud-provider integrations in v1
Suggested stack
- Frontend
- Docs site: Astro Starlight
- Backend or API
- Node.js CLI published to npm (TypeScript, zero runtime dependencies where possible)
- Payments
- Lemon Squeezy (licence keys)
- Hosting
- npm for the CLI; docs on Vercel or Netlify
Repository metadata
- Blueprint ID
env-file-diff-validator- Category ID
dev_tools- Monetization ID
one_time
Day-one distribution
Channels
- Reddit r/node and r/webdev (follow rules)
- Hacker News 'Show HN'
- dev.to tutorial: catching missing env vars in CI
Reddit strategy
Share the free diff command and a short write-up on env var mistakes that break deploys.
Cold outreach or directory hook
List on developer tool directories and open-source tool roundups with the free diff command.
Search keywords
compare env files, validate env variables in ci, dotenv schema validation
One-shot master prompt
Build a Node.js + TypeScript CLI called "envcheck" and publish it to npm. Core requirements: 1. `envcheck diff <fileA> <fileB> [...]`: parse dotenv files (support quotes, comments, multiline values) and print a table of keys present/missing per file. Never print values; show only "set", "empty" or "missing". 2. `envcheck validate --schema env.schema.json <file>`: rules per key (required, type string/number/boolean/url/email, enum, min/max, regex). Print clear errors and exit with code 1 on failure. 3. `envcheck scan-example .env.example`: warn when values look like real secrets (long high-entropy strings, common key prefixes) and suggest placeholders. 4. `--ci` flag with machine-readable JSON output, plus a GitHub Action (action.yml) that runs validate on pull requests. 5. Licence: diff is free; validate, scan-example and CI mode require a licence key verified against the Lemon Squeezy licence API once and cached locally for 30 days.
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Published 2026-10-08.
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