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

# Installation

> Learn how to install the SendLayer SDKs

## Overview

This guide shows you how to install the SendLayer SDKs for popular languages so you can start integrating quickly. We currently provide SDKs for Node.js, Python, PHP, Ruby, and Go.

## Prerequisites

Before using the SendLayer API, make sure you've:

* Authorized your [sending domain](https://sendlayer.com/docs/authorizing-your-domain/)
* Created or retrieved your [SendLayer API key](https://sendlayer.com/docs/managing-api-keys/)

## Node.js

Install the SendLayer Node.js SDK using your preferred package manager.

<CodeGroup>
  ```bash npm theme={null}
  npm install sendlayer
  ```

  ```bash yarn theme={null}
  yarn add sendlayer
  ```
</CodeGroup>

#### Validate Installation

Create a file (for example, `checkInstall.js`) and run a quick import:

```javascript checkInstall.js theme={null}
import { SendLayer } from 'sendlayer';

const sendlayer = new SendLayer('your-api-key');
console.log('SendLayer initialized:', !!sendlayer);
```

<Note>Replace `'your-api-key'` with your actual API key. See our [Node.js SDK guide](/sdks/nodejs) for full usage examples.</Note>

## Python

Install the SendLayer Python SDK via `pip`:

```bash theme={null}
pip install sendlayer
```

#### Validate Installation

Create a file (for example, `check_install.py`) and run:

```python check_install.py theme={null}
from sendlayer import SendLayer

sendlayer = SendLayer('your-api-key')
print('SendLayer initialized:', bool(sendlayer))
```

<Note>Replace `'your-api-key'` with your actual API key. See our [Python SDK guide](/sdks/python) for full usage examples.</Note>

## PHP

Install the SendLayer PHP SDK with Composer:

```bash theme={null}
composer require sendlayer/sendlayer-php
```

#### Validate Installation

Create a file (for example, `checkInstall.php`) and run:

```php checkInstall.php theme={null}
<?php
require_once 'vendor/autoload.php';

use SendLayer\SendLayer;

$sendlayer = new SendLayer('your-api-key');
echo 'SendLayer initialized: ' . ($sendlayer ? 'true' : 'false');
```

<Note>Replace `'your-api-key'` with your actual API key. See our [PHP SDK guide](/sdks/php) for full usage examples.</Note>

## Ruby

Install the SendLayer Ruby SDK via RubyGems:

```bash theme={null}
gem install sendlayer
```

#### Validate Installation

Create a file (for example, `check_install.rb`) and run:

```ruby check_install.rb theme={null}
require 'sendlayer'

sendlayer = SendLayer::SendLayer.new('your-api-key')
puts "SendLayer initialized: #{!sendlayer.nil?}"
```

<Note>Replace `'your-api-key'` with your actual API key. See our [Ruby SDK guide](/sdks/ruby/send-with-ruby) for full usage examples.</Note>

## Go

Install the SendLayer Go SDK using `go get`:

```bash theme={null}
go get github.com/sendlayer/sendlayer-go
```

#### Validate Installation

Create a file (for example, `check_install.go`) and run:

```go check_install.go theme={null}
package main

import (
	"fmt"
	"github.com/sendlayer/sendlayer-go"
)

func main() {
	sl := sendlayer.New("your-api-key")
	fmt.Println("SendLayer initialized:", sl != nil)
}
```

<Note>Replace `'your-api-key'` with your actual API key. See our [Go SDK guide](/sdks/go/send-with-go) for full usage examples.</Note>

## Next Steps

* Send your first email: [Send Email](/guides/send-email)
* Add attachments: [Send Email with Attachments](/guides/send-email-with-attachments)
* Send to multiple recipients: [Send Email to Multiple Recipients](/guides/send-email-to-multiple-recipients)
* Manage webhooks: [Managing Webhooks](/guides/manage-webhooks)
* Retrieve events: [Retrieving Email Events](/guides/get-events)

## Troubleshooting

* Ensure your environment can make outbound HTTPS requests
* Verify your API key is correct and active
* If installation fails, update your package manager (`npm`, `yarn`, `pip`, or `composer`) and try again
* Check language version requirements (Node.js 16+, Python 3.8+, PHP 7.4+)