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

# Send emails with Ruby

> Learn how to send your first email using the Resend Ruby SDK.

## Prerequisites

Before you start, you'll need:

* A Resend [API key](/docs/create-an-api-key)
* A [verified domain](/docs/add-a-domain)

## Guide

**1. Install**

Get the Resend Ruby SDK.

```bash RubyGems theme={"theme":{"light":"github-light","dark":"vesper"}}
gem install resend
```

```bash Gemfile theme={"theme":{"light":"github-light","dark":"vesper"}}
gem 'resend'
```

**2. Send email using HTML**

The easiest way to send an email is by using the `html` parameter.

```rb index.rb theme={"theme":{"light":"github-light","dark":"vesper"}}
require "resend"

Resend.api_key = "re_xxxxxxxxx"

params = {
  "from": "Acme <onboarding@resend.dev>",
  "to": ["delivered@resend.dev"],
  "subject": "hello world",
  "html": "<strong>it works!</strong>"
}

sent = Resend::Emails.send(params)
puts sent
```

## Examples

> **[Basic Send](https://github.com/resend/resend-examples/blob/main/ruby-resend-examples/examples/basic_send.rb)**
>
> Basic email sending

> **[Attachments](https://github.com/resend/resend-examples/blob/main/ruby-resend-examples/examples/with_attachments.rb)**
>
> Send emails with file attachments

> **[Templates](https://github.com/resend/resend-examples/blob/main/ruby-resend-examples/examples/with_template.rb)**
>
> Send emails using Resend hosted templates

> **[Scheduling](https://github.com/resend/resend-examples/blob/main/ruby-resend-examples/examples/scheduled_send.rb)**
>
> Schedule emails for future delivery

> **[Audiences](https://github.com/resend/resend-examples/blob/main/ruby-resend-examples/examples/audiences.rb)**
>
> Manage contacts and audiences

> **[Domains](https://github.com/resend/resend-examples/blob/main/ruby-resend-examples/examples/domains.rb)**
>
> Create and manage sending domains

> **[Inbound Webhooks](https://github.com/resend/resend-examples/blob/main/ruby-resend-examples/examples/inbound.rb)**
>
> Receive and process inbound emails

> **[Double Opt-in](https://github.com/resend/resend-examples/tree/main/ruby-resend-examples/examples/double_optin)**
>
> Double opt-in subscription flow

> **[Sinatra App](https://github.com/resend/resend-examples/tree/main/ruby-resend-examples/sinatra_app)**
>
> Full Sinatra web application

> **[Rails App](https://github.com/resend/resend-examples/tree/main/ruby-resend-examples/rails_app)**
>
> Full Rails web application