@shxlab/env-inject

A minimal and fast CLI tool to inject environment variables directly into files at build time — ideal for Docker, CI/CD, and static frontend frameworks.

🚀 Why use env-inject?

This utility helps in scenarios where:

• Environment variables aren't accessible during ng build, vite build, or next build
• You want to inject values at build time, not runtime
• You want to avoid bundling process.env.* into frontend code
• You want to ensure secrets never get committed into git
• You prefer simple, file-based environment injection instead of build system hacks

Think of it as a lightweight, build-time envsubst for TypeScript, JSON, or any text-based config file.

📦 Installation

npm install -g @shxlab/env-inject

Or run without installing:

npx @shxlab/env-inject <file>

🔧 Usage

▶️ Inject environment variables

# Replaces all {{process.env.VAR_NAME}} with actual values from process.env
env-inject config.ts

♻️ Restore from backup

# Restores original file from .bak file
env-inject config.ts --restore

💡 Example

🔹 Original file: config.ts

export const config = {
  apiUrl: '{{process.env.API_URL}}',
  port: {{process.env.PORT}},
  debug: {{process.env.DEBUG}}
};

🔹 After running:

API_URL=https://api.example.com PORT=3000 DEBUG=true \
npx @shxlab/env-inject config.ts

🔹 Output:

export const config = {
  apiUrl: "https://api.example.com",
  port: 3000,
  debug: true,
};

✅ Features

• 🔁 Replaces {{process.env.VAR}} with actual values
• 🧾 Automatically creates .bak backups before changes
• 🔙 --restore flag restores files from .bak
• 💡 No external dependencies — pure Node.js + TypeScript
• 📦 Ready for use in Docker and CI pipelines
• 🚫 Prevents hardcoding env values in source control

🛠 Development

# Install dependencies
npm install

# Build with tsup
npm run build

# Watch changes during development
npm run dev

# Clean build output
npm run clean

📄 License

MIT — use it freely in your projects.