Capabilities

import { Effect } from "effect";
import { Email } from "@effect-kit/emails";
import * as MailerSend from "@effect-kit/emails/mailersend";

const program = Effect.gen(function* () {
  const email = yield* Email;
  return yield* email.send({
    from: "billing@example.com",
    to: "ada@example.com",
    subject: "Invoice",
    text: "Your invoice is attached.",
    attachments: [
      {
        filename: "invoice.pdf",
        contentType: "application/pdf",
        content: new Uint8Array([37, 80, 68, 70]),
      },
    ],
  });
}).pipe(
  Effect.catchReason("EmailError", "UnsupportedFeatureError", (reason) =>
    Effect.succeed(`unsupported: ${reason.feature}`),
  ),
  Effect.provide(MailerSend.layerConfig()),
);
// Output: "unsupported: attachments"

import { Effect } from "effect";
import { Email } from "@effect-kit/emails";

const send = Effect.gen(function* () {
  const email = yield* Email;
  const { idempotency } = email.capabilities;
  return yield* email.send(
    {
      from: "hello@example.com",
      to: "ada@example.com",
      subject: "Welcome",
      text: "Your account is ready.",
    },
    idempotency.mode === "unsupported" ? {} : { idempotencyKey: "welcome/account-123" },
  );
});