Resend mail sender

Resend as the carrier for Osysharp.Mail: the app's outbox hands each message to Resend, with its Message-ID and threading headers, its attachments and its pictures, and records Resend's id for it.

Use it

// app.osy
use Osysharp.Mail@0;
use Osysharp.Mail.Resend@0 { egress "api.resend.com"; }
use Osysharp.Resend@0 { egress "api.resend.com"; }
use Osysharp.Http;

using Osysharp.Mail;
using Osysharp.Mail.Resend;

app.Mail = new MailSetup {
  Sender = new ResendSender { ApiKey = Security.IsSecretSet("ResendApiKey") ? Secret.ResendApiKey : "" },
  From = "Acme <[email protected]>",          // on a domain you have verified with Resend
};
app.Secrets = [ new Secret("ResendApiKey") ];

Then osy secret set ResendApiKey. Until the key is set the sender is not ready, and mail waits in the outbox as held instead of failing — the app works in the meantime.

The key is a setting the app fills from its own secret: this package never learns the secret's name, and it reaches no host but api.resend.com.

Why it is a package of its own

Osysharp.Resend is a plain Resend client for any app. This package is the few lines that make it an Osysharp.Mail sender, so an app that does not use the outbox is not handed its tables.

Get it

Add the kit to your app’s manifest:

app MyApp {
  use Osysharp.Mail.Resend@0 {
    egress "api.resend.com";
  }
}

Then run osy lock: it downloads the release, verifies it by its content address and pins that version in osyrin.lock. osy kits Osysharp.Mail.Resend shows what the kit is for, from inside your app.

Reference: osy docs ui-mail-kit.