Resent is the official Ruby client for resent.one — a transactional email API built for product and platform teams. Install with: gem install resent (or add gem "resent" to your Gemfile). Create an API key in the Resent dashboard, set RESENT_API_KEY, then send mail with a few lines of Ruby: require "resent" resent = Resent.new(ENV.fetch("RESENT_API_KEY")) resent.emails.send( from: "Acme ", to: "you@example.com", subject: "Hello World", html: "<strong>It works!</strong>" ) Uses only Ruby stdlib (Net::HTTP + JSON) — no extra runtime gems. Supports html and/or text bodies, plus cc, bcc, and reply_to. Docs: https://developers.resent.one/sdks/ruby Dashboard: https://resent.one Source: https://github.com/resentmail/resent-ruby