Resend Provider

The Resend provider allows you to send emails through the Resend API, a modern email API for developers.

Runtime Support: Universal (Node.js, Deno, Bun, Cloudflare Workers)

Setup

import { createMail } from "@visulima/email";
import { resendProvider } from "@visulima/email/providers/resend";

const mail = createMail(
    resendProvider({
        apiKey: process.env.RESEND_API_KEY!,
    }),
);

Configuration

The ResendConfig interface extends BaseConfig with the following options:

Option	Type	Required	Default	Description
`apiKey`	`string`	Yes	-	Your Resend API key (starts with `re_`)
`endpoint`	`string`	No	`https://api.resend.com`	Custom API endpoint
`debug`	`boolean`	No	`false`	Enable debug logging
`logger`	`Console`	No	-	Custom logger instance
`retries`	`number`	No	`3`	Number of retry attempts on failure
`timeout`	`number`	No	`30000`	Request timeout in milliseconds

Basic Usage

import { MailMessage } from "@visulima/email";

const message = new MailMessage()
    .to("user@example.com")
    .from("sender@example.com")
    .subject("Hello from Resend")
    .html("<h1>Hello World</h1>");

const result = await mail.send(message);

Provider-Specific Email Options

The Resend provider supports additional options through ResendEmailOptions:

Tags

Tags can be used for categorizing emails. Tag names and values must only contain ASCII letters, numbers, underscores, or dashes. Tag names have a max length of 256 characters.

import type { ResendEmailOptions } from "@visulima/email/providers/resend";

const options: ResendEmailOptions = {
    from: { email: "sender@example.com" },
    to: { email: "user@example.com" },
    subject: "Tagged email",
    html: "<h1>Hello</h1>",
    tags: [
        { name: "category", value: "welcome" },
        { name: "environment", value: "production" },
    ],
};

Scheduled Sending

const options: ResendEmailOptions = {
    from: { email: "sender@example.com" },
    to: { email: "user@example.com" },
    subject: "Scheduled email",
    html: "<h1>Hello</h1>",
    scheduledAt: new Date("2025-01-15T10:00:00Z"),
};

Template-Based Emails

const options: ResendEmailOptions = {
    from: { email: "sender@example.com" },
    to: { email: "user@example.com" },
    subject: "Template email",
    html: "",
    templateId: "tmpl_xxx",
    templateData: {
        name: "John",
        company: "Acme",
    },
};

Supported Features

Feature	Supported
Attachments	Yes
Batch Sending	Yes
Custom Headers	Yes
HTML	Yes
Reply-To	Yes
Scheduling	Yes
Tagging	Yes
Templates	Yes
Tracking	Yes

Additional Methods

Retrieve Email

You can retrieve email details by ID:

const provider = resendProvider({ apiKey: "re_xxx" });
const result = await provider.getEmail("email-id");

Validate Credentials

const isValid = await provider.validateCredentials();

Resend