Email — Service/Transactional

Service/transactional email extension for Caffeine AI.

Overview

This skill adds support for sending service and transactional emails from the backend canister. Use sendServiceEmail for order confirmations, notifications, and similar one-off emails.

Backend

This component is for sending service/transactional emails.

There is the prefabricated module mo:caffeineai-email/emailClient.mo which cannot be modified.

• Use the sendServiceEmail function.
• Each recipient is sent an individual email
• It returns a SendResult which is #ok if the email is sent successfully otherwise #err(error) with the error text.
• A failed send never throws. Every failure, a gateway error included, comes back as #err.

module {
  public type SendResult = {
    #ok;
    #err : Text;
  };

  public func sendServiceEmail(
    fromUsername : Text,
    recipients : [Text],
    subject : Text,
    htmlBody : Text,
  ) : async SendResult;
};

Usage for sendServiceEmail:

import Runtime "mo:core/Runtime";
import EmailClient "mo:caffeineai-email/emailClient";

actor {
  public func sendOrderConfirmationEmail(recipientEmailAddress : Text, username : Text, orderReference : Text) : async () {
    let result = await EmailClient.sendServiceEmail(
      "no-reply",
      [recipientEmailAddress],
      "Order " # orderReference # " confirmed",
      "Hello " # username # ",\nYour order " # orderReference # " has been confirmed. Your items will ship tomorrow.",
    );
    switch (result) {
      case (#ok) {};
      case (#err(error)) {
        Runtime.trap("Failed to send order confirmation email: " # error);
      };
    };
  };
};

Upgrading from the previous version

An app built with caffeineai-email 0.3.x re-pins with mops add caffeineai-email@0.4.0. sendServiceEmail and sendRawEmail keep their signatures. Every send now goes through the mail gateway with the settings the platform injects on every deploy (INTEGRATIONS_GATEWAY_URL / INTEGRATIONS_GATEWAY_API_KEY); the transport canister and INTEGRATIONS_CANISTER_ID are no longer used, and a send without those settings returns #err instead of falling back. Apps that use verification, marketing or calendar email follow the upgrade sections of those skills.

An app built with caffeineai-email 0.2.x re-pins with mops add caffeineai-email@0.3.0. sendServiceEmail and sendRawEmail keep their signatures; every send now carries an idempotency key, so a retried outcall is sent and charged once. Apps that use verification or marketing email follow the upgrade sections of those skills.