# Utilities

The **SSK-Core** utilities module provides essential helper functions designed to streamline environment management, client/server detection, and secure access to environment variables. These utilities are a core part of **SSK-Core**'s functionality, simplifying tasks that are commonly needed across different areas of your project.

***

### **Core Features**

1. **Environment Detection**: Easily determine if the code is running in a development environment or whether it’s executing on the client (browser) or server (Node.js).
2. **Dynamic Host Retrieval**: Automatically retrieve the host URLs depending on whether you’re working locally or in a production environment, making it simple to manage local and production setups.
3. **Environment Variable Access**: Securely fetch and validate environment variables with flexible error handling. This reduces the chance of runtime failures by ensuring that essential variables are always available in production environments.

***

### **How to Use**

#### **1. Client-Side Environment Variable Validation**

Use `checkRequiredEnvVar` to ensure critical environment variables are defined on the client side. It allows for flexible handling during development and strict enforcement in production.

**Example**:

```typescript
import { checkRequiredEnvVar } from '@core/utils'

const apiUrl = checkRequiredEnvVar(
  'NEXT_PUBLIC_API_URL',
  process.env.NEXT_PUBLIC_API_URL,
)
console.log(`API URL: ${apiUrl}`)
```

* **Development Behavior**: Logs an error if the variable is missing but allows you to continue.
* **Production Behavior**: Throws an error if the variable is missing, preventing potentially unstable behavior.

***

#### **2. Server-Side Environment Variable Retrieval**

Use `getEnvVar` to safely fetch and validate environment variables in server-side code. This utility ensures secure access and avoids unintended exposure of environment variables to the client.

**Example**:

```typescript
import { getEnvVar } from '@core/utils'

const dbConnectionString = getEnvVar('DATABASE_URL')
console.log(`Database Connection String: ${dbConnectionString}`)
```

* **Server-Side Only**: Throws an error if used on the client side.
* **Integrated Validation**: Automatically leverages `checkRequiredEnvVar` for robust validation.

***

### **Other Utilities**

#### **Development Environment Check**

Verify if the project is running in a development environment:

```typescript
if (checkIsDev()) {
  console.log('Development mode is active')
}
```

#### **Host URL Retrieval**

Retrieve the appropriate host URL based on the environment using `getHost`:

```typescript
const currentHost = getHost()
console.log(`Current host: ${currentHost}`)
```

This feature ensures that both local development and production environments are handled seamlessly, reducing issues with hardcoded URLs.

***

By leveraging these utilities, you can streamline environment management, improve development efficiency, and ensure a smooth transition between local and production environments.