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Stop Leaking Secrets: How EnvGuard Catches API Keys in Your .env Files

#security #node #opensource #devops

Stop Leaking Secrets: How EnvGuard Catches API Keys in Your .env Files

Every year, thousands of API keys and secrets are accidentally pushed to GitHub. EnvGuard is a zero-dependency CLI tool that catches them before it's too late.

The Problem

We've all been there — you're rushing to deploy, push your code, and suddenly realize your .env file containing AWS keys, database passwords, and GitHub tokens just went public. By the time you notice, automated scrapers have already harvested your credentials.

According to GitHub's own research, over 1.7 million secrets were leaked on the platform in a single year. The average time to rotate a compromised key? Hours of downtime and thousands of dollars.

Meet EnvGuard

EnvGuard is an all-in-one CLI tool for environment variable validation, security scanning, and documentation generation. It's built with zero external dependencies — pure Node.js, no supply chain risk.

npm install -g @anhuijie/envguard
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The Security Scanner That Catches What You Miss

Let's say you have a .env file like this:

# .env
NODE_ENV=production
DATABASE_URL=postgres://admin:s3cretP@ss@db.example.com:5432/mydb
AWS_ACCESS_KEY_ID=AKIAIOSFODNN7EXAMPLE
GITHUB_TOKEN=ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
STRIPE_SECRET_KEY=sk_live_51Hxxxxxxxxxxxxxxxxxxxxxx
APP_SECRET=my-super-secret-jwt-key-2024
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Run the scanner:

envguard check
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Output:

🔍 Scanning environment variables for secrets...

🔴 CRITICAL: AWS Access Key detected in "AWS_ACCESS_KEY_ID"
🔴 CRITICAL: GitHub Token detected in "GITHUB_TOKEN"
🔴 CRITICAL: Stripe Key detected in "STRIPE_SECRET_KEY"
🔴 CRITICAL: Database URL with Password detected in "DATABASE_URL"
🟠 HIGH: JWT Secret detected in "APP_SECRET"

📊 Summary: 5 findings (4 critical, 1 high)
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What It Detects

Secret Type Severity Pattern
AWS Access Key Critical AKIA prefix + 16 alphanumeric chars
AWS Secret Key Critical aws + secret/key context
GitHub Token Critical ghp_ / ghs_ prefix
GitLab Token Critical glpat- prefix
Slack Token Critical xoxb- / xoxp- prefix
Stripe Live Key Critical sk_live_ prefix
Private Key Critical -----BEGIN PRIVATE KEY-----
JWT Secret High jwt + secret/key context
Database URL with Password High Connection string with embedded credentials
Generic API Key / Password / Secret High/Medium Common key name patterns

Beyond Scanning: Full Environment Safety

Security scanning is just one piece. EnvGuard also provides:

Schema Validation

Define what your environment variables should look like:

// envguard.config.js
module.exports = {
  schema: {
    NODE_ENV: {
      required: true,
      type: 'string',
      enum: ['development', 'staging', 'production', 'test'],
    },
    PORT: {
      required: false,
      type: 'port',
      default: '3000',
    },
    DATABASE_URL: {
      required: true,
      type: 'url',
    },
  },
};
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envguard validate
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Catches missing required variables, wrong types, invalid ports, and more — before your app crashes in production.

Auto Documentation 

envguard docs
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Generates .env.example and ENV.md from your schema, so your team always knows which variables are needed.

Environment Diff 

envguard diff .env.development .env.production
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Compare .env files across environments to find configuration drift before it causes issues.

CI/CD Integration

Add EnvGuard to your GitHub Actions pipeline:

name: Env Safety Check
on: [push, pull_request]

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
      - run: npm install -g @anhuijie/envguard
      - name: Validate environment config
        run: envguard validate
      - name: Security scan
        run: envguard check
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The command exits with code 1 on validation errors or critical findings, failing the build and preventing secrets from reaching production.

Programmatic API

Use EnvGuard in your own tools:

const { validateEnv, scanForSecrets, generateEnvExample } = require('@anhuijie/envguard');

// Validate
const result = validateEnv(process.env, schema);
if (!result.valid) {
  console.error('Invalid config:', result.errors);
}

// Scan
const secrets = scanForSecrets(process.env);
if (secrets.hasCritical) {
  throw new Error('Critical secrets detected!');
}

// Generate docs
const example = generateEnvExample(schema);
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Why EnvGuard?

Feature EnvGuard dotenv convict env-schema
Schema Validation ✅ ❌ ✅ ✅
Secret Scanning ✅ ❌ ❌ ❌
Auto Documentation ✅ ❌ ❌ ❌
Environment Diff ✅ ❌ ❌ ❌
Zero Dependencies ✅ ❌ ❌ ❌
CLI + API ✅ ❌ ❌ ❌

Get Started 

# Install globally
npm install -g @anhuijie/envguard

# Or use without installing
npx @anhuijie/envguard init
npx @anhuijie/envguard validate
npx @anhuijie/envguard check
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Top comments (1)

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theoephraim profile image
Theo Ephraim •

Check out varlock.dev - it is a mature solution that will solve your problems, and does a lot more -- like loading from various backends using plugins, and additional security guardrails like leak detection and log redaction.

Sidenote - search github for "envguard" - there literally hundreds vibe coded repos popping up solving this problem. Search just this site - there are a few that popped up in the last few months.