Send emails with Ruby

Send email from Ruby with the first-party OpenSend Ruby SDK. It works in Rails, Sinatra, Ruby scripts, and background jobs.

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Install

The opensend gem package is ready for RubyGems publishing. Until the RubyGems release is available, build and install it from this repository:

bash

cd packages/ruby-sdk
gem build opensend.gemspec
gem install ./opensend-0.1.0.gem

After publication, use:

bash

gem install opensend

Configure

bash

export OPENSEND_API_KEY="os_your_api_key"
export OPENSEND_BASE_URL="http://localhost:3015" # optional for self-hosting

If OPENSEND_BASE_URL is unset, the SDK targets https://opensend.namuh.co.

Send one email

ruby

require "opensend"

OpenSend.api_key ENV.fetch("OPENSEND_API_KEY")
OpenSend.base_url ENV.fetch("OPENSEND_BASE_URL", OpenSend::DEFAULT_BASE_URL)

email = OpenSend.emails.send(
  from: "hello@yourdomain.com",
  to: "recipient@example.com",
  subject: "Hello from OpenSend",
  html: "<h1>It works!</h1>"
)

puts email.fetch("id")

Instance client

Use an instance client when a process needs multiple API keys or base URLs:

ruby

client = OpenSend::Client.new(
  api_key: ENV.fetch("OPENSEND_API_KEY"),
  base_url: ENV.fetch("OPENSEND_BASE_URL", OpenSend::DEFAULT_BASE_URL)
)

client.emails.send(
  from: "hello@yourdomain.com",
  to: "recipient@example.com",
  subject: "Hello",
  text: "It works!"
)

Idempotency and batch sends

ruby

client.emails.send(payload, idempotency_key: "receipt-123")
client.emails.send_batch([payload_one, payload_two], idempotency_key: "batch-123")

Framework guides

The Ruby package also exports Resend as a compatibility alias for migration-oriented code.