@aletso/effect-resend

Effect service wrapper for the Resend email API.

The package provides:

• Resend service tag
• Resend.layer(config) for dependency injection
• ResendError for typed failures

Install

pnpm add @aletso/effect-resend resend effect

Provide the layer

import * as Resend from "@aletso/effect-resend/Resend";
import * as Layer from "effect/Layer";
import * as Redacted from "effect/Redacted";

export const ResendLive: Layer.Layer<Resend.Resend> = Resend.layer({
  apiKey: Redacted.make(process.env.RESEND_API_KEY ?? ""),
});

Example environment-driven layer wiring:

import { EnvVars } from "./env";
import * as Resend from "@aletso/effect-resend/Resend";
import { Effect, Layer } from "effect";

export const ResendLive = Layer.unwrapEffect(
  EnvVars.pipe(
    Effect.map((env) =>
      Resend.layer({
        apiKey: env.RESEND_API_KEY,
      }),
    ),
  ),
).pipe(Layer.provide(EnvVars.Live));

Send email from an Effect service

import { Resend, ResendError } from "@aletso/effect-resend/Resend";
import * as Effect from "effect/Effect";

export const sendWelcomeEmail = (to: string) =>
  Effect.gen(function* () {
    const resend = yield* Resend;
    return yield* resend.sendEmail({
      from: "Acme <[email protected]>",
      to: [to],
      subject: "Welcome",
      html: "<p>Thanks for joining Acme.</p>",
    });
  }).pipe(
    Effect.catchTag("ResendError", (error: ResendError) =>
      Effect.zipRight(
        Effect.logError(`Resend sendEmail failed: ${error.message}`),
        Effect.fail(error),
      ),
    ),
  );

Composition example

import * as Layer from "effect/Layer";
import * as Resend from "@aletso/effect-resend/Resend";
import * as Redacted from "effect/Redacted";
import { NewsletterService } from "./newsletter/service";

export const AppLive = Layer.mergeAll(
  Resend.layer({ apiKey: Redacted.make(process.env.RESEND_API_KEY ?? "") }),
  NewsletterService.Default,
);

API surface

• ResendConfig
• ResendError
• ResendService
• make(config)
• Resend tag
• layer(config)