# Send email from DaloyJS with Resend [Resend](https://resend.com) is an email API with first-class TypeScript types, edge-runtime support, and tight integration with [React Email](https://react.email) templates. It's an excellent default for new DaloyJS projects. **Diagram: Send through the resend SDK** Participants: Route handler, Resend SDK, Resend API, Webhooks 1. **Route handler -> Resend SDK** (request) - resend.emails.send({ from, to, subject }) - uses the standard fetch API (edge-friendly) 2. **Resend SDK -> Resend API** (request) - HTTPS request - Bearer RESEND_API_KEY 3. **Resend API -> Route handler** (response) - { data, error } - throw on error, else return { id: data.id } 4. **Resend API -> Webhooks** (async) - delivered, bounced, complained events - verify the signature before trusting payloads resend.emails.send() runs on the standard fetch API, so it works on edge runtimes too. The SDK returns { data, error } rather than throwing, so handle the error branch and return data.id on success. ## 1. Provision 1. Sign up at [resend.com](https://resend.com) and add a sending **domain** under **Domains**. Add the SPF, DKIM, and DMARC DNS records Resend lists, then click *Verify*. 2. Create an **API key** under **API Keys**. Use a “Sending access” key scoped to that domain. ## 2. Install ```ts pnpm add resend ``` ## 3. Environment variables ```ts # .env RESEND_API_KEY=re_xxxxxxxxxxxxxxxxxxxxxx RESEND_FROM="Acme " ``` ## 4. Plugin ```ts // src/plugins/resend.ts import { Resend } from "resend"; import type { App } from "@daloyjs/core"; const resend = new Resend(process.env.RESEND_API_KEY); export const resendPlugin = { name: "resend", register(app: App) { app.decorate("email", { async send({ to, subject, text, html }) { const { data, error } = await resend.emails.send({ from: process.env.RESEND_FROM!, to, subject, text, html, }); if (error) throw new Error(error.message); return { id: data?.id ?? "" }; }, }); }, }; declare module "@daloyjs/core" { interface AppState { email: { send(msg: { to: string; subject: string; text?: string; html?: string; }): Promise<{ id: string }>; }; } } ``` Resend SDK methods return `{ data, error }` rather than throwing, handle the `error` branch and surface it through the [DaloyJS error helpers](/docs/errors). ## 5. Use it in a route ```ts import { z } from "zod"; import { App, secureHeaders, rateLimit } from "@daloyjs/core"; import { resendPlugin } from "./plugins/resend.ts"; const app = new App(); app.use(secureHeaders()); app.use(rateLimit({ windowMs: 60_000, max: 10 })); app.register(resendPlugin); app.post( "/magic-link", { operationId: "sendMagicLink", request: { body: z.object({ email: z.email() }), }, responses: { 202: { description: "Sent", body: z.object({ id: z.string() }) }, }, }, async ({ body, state }) => { const link = await issueMagicLink(body.email); // your own logic const { id } = await state.email.send({ to: body.email, subject: "Your sign-in link", text: `Sign in: ${link}`, html: `

Sign in: ${link}

`, }); return { status: 202, body: { id } }; }, ); async function issueMagicLink(_email: string) { return "https://acme.example.com/auth/callback?token=..."; } ``` ## React Email templates Resend reads the `react` field and renders it to HTML for you, so you can ship type-safe email templates as React components: ```ts pnpm add @react-email/components react react-dom ``` ```ts // emails/welcome.tsx import { Html, Button, Heading, Text } from "@react-email/components"; export default function Welcome({ name }: { name: string }) { return ( Welcome, {name}! Thanks for joining Acme. ); } // in the handler import Welcome from "../../emails/welcome.tsx"; await resend.emails.send({ from: process.env.RESEND_FROM!, to, subject: "Welcome to Acme", react: Welcome({ name: "Devlin" }), }); ``` ## Batch sending Use `resend.batch.send([...])` to enqueue up to 100 messages in a single API call, handy for fan-out notifications without queueing infrastructure. ## Runtimes The `resend` SDK uses the standard `fetch` API, so it runs on Node 18+, Bun, Deno, AWS Lambda, Vercel (Serverless and Edge), and Cloudflare Workers without adapters. Pair it with the [edge adapters](/docs/adapters) shipped by DaloyJS. See also [Postmark](/docs/email/postmark), [SendGrid](/docs/email/sendgrid), and the [email integrations overview](/docs/email). --- Source: https://daloyjs.dev/docs/email/resend