> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/dotandev/envcheck/llms.txt
> Use this file to discover all available pages before exploring further.

# Node.js Project

> Environment validation for Node.js applications

## Overview

This example demonstrates how to configure envcheck for a typical Node.js application. It validates Node.js and npm versions, required environment variables, port availability, and essential project files.

## Configuration

```yaml .envcheck.yaml theme={null}
version: "1"

tools:
  - name: node
    version: ">=18.0.0"
    required: true
  - name: npm
    version: ">=9.0.0"
    required: true
  - name: git
    required: true

env_vars:
  - name: NODE_ENV
    required: false
  - name: DATABASE_URL
    required: true

ports:
  - 3000
  - 5432

files:
  - path: .env
    required: true
  - path: package.json
    required: true
```

## What This Checks

### Tools

* **node >=18.0.0**: Ensures you're running a modern LTS version of Node.js with the latest features and security patches
* **npm >=9.0.0**: Validates you have a compatible npm version with improved workspace support
* **git**: Confirms git is installed for version control operations

### Environment Variables

* **NODE\_ENV** (optional): Standard Node.js environment variable for development/production modes
* **DATABASE\_URL** (required): Connection string for database access - critical for application functionality

### Ports

* **3000**: Default development server port for most Node.js frameworks (Express, Next.js, etc.)
* **5432**: PostgreSQL database port - ensures no conflicts with local database

### Files

* **.env**: Local environment configuration file must exist
* **package.json**: Project manifest is required for dependency management

## Expected Output

<CodeGroup>
  ```bash Success theme={null}
  $ envcheck

  ✓ Tools
    ✓ node: 18.17.0 (>= 18.0.0)
    ✓ npm: 9.6.7 (>= 9.0.0)
    ✓ git: installed

  ✓ Environment Variables
    ✓ NODE_ENV: development
    ✓ DATABASE_URL: ***

  ✓ Ports
    ✓ 3000: available
    ✓ 5432: available

  ✓ Files
    ✓ .env: exists
    ✓ package.json: exists

  All checks passed!
  ```

  ```bash Failure theme={null}
  $ envcheck

  ✗ Tools
    ✗ node: 16.14.0 (expected >= 18.0.0)
    ✓ npm: 9.6.7 (>= 9.0.0)
    ✓ git: installed

  ✗ Environment Variables
    ✓ NODE_ENV: development
    ✗ DATABASE_URL: not set

  ✗ Ports
    ✗ 3000: in use
    ✓ 5432: available

  ✓ Files
    ✓ .env: exists
    ✓ package.json: exists

  Checks failed!
  ```
</CodeGroup>

## Tips for Node.js Projects

<Tip>
  Use `.env.example` as a template file committed to git, and create your local `.env` from it. Add `.env` to your `.gitignore` to prevent committing secrets.
</Tip>

<Warning>
  If port 3000 is in use, you may have another dev server running. Use `lsof -i :3000` on macOS/Linux or `netstat -ano | findstr :3000` on Windows to find the process.
</Warning>

<Info>
  For monorepo setups with multiple Node.js services, create separate `.envcheck.yaml` files in each package directory with service-specific configurations.
</Info>

## Common Variations

### TypeScript Projects

Add TypeScript compiler checks:

```yaml theme={null}
tools:
  - name: node
    version: ">=18.0.0"
    required: true
  - name: npm
    version: ">=9.0.0"
    required: true
  - name: tsc
    required: true

files:
  - path: tsconfig.json
    required: true
```

### Next.js Applications

Check for Next.js-specific requirements:

```yaml theme={null}
env_vars:
  - name: NEXT_PUBLIC_API_URL
    required: true
  - name: NEXTAUTH_SECRET
    required: true

ports:
  - 3000
```

### Microservices

Validate additional service dependencies:

```yaml theme={null}
tools:
  - name: docker
    required: true
  - name: docker-compose
    required: true

ports:
  - 3000  # API service
  - 3001  # Auth service
  - 6379  # Redis
```

## Learn More

* [Tools Validator](/configuration/tools) - Version constraints and tool detection
* [Environment Variables](/configuration/environment-variables) - Pattern matching and validation
* [Port Checker](/configuration/ports) - Port availability testing
* [File Validator](/configuration/files) - Path and permission checks