Introduction

Postboi is a framework-agnostic email library optimised for SvelteKit. It works with a variety of email providers and turns your FormData into tidy HTML emails, with zero configuration.

Import send, call it, done — the provider and credentials come from environment variables, so the same line of code works whether you’re on Resend, Postmark, Mailgun, or any of the other supported providers.

import { send } from 'postboi';

await send({ to: 'contact@example.com', subject: 'Hi', body: '<p>Hello</p>' });

import { send } from 'postboi';

await send({ to: 'contact@example.com', subject: 'Hi', body: '<p>Hello</p>' });

Features

• 👨‍💻 Zero configuration — works out of the box with minimal setup.
• 🔌 Provider-based — swap email providers without changing your code.
• 📝 Smart FormData parsing — automatically converts FormData to HTML tables.
• 🎯 Grouped fields — organise form fields with fieldset→field syntax.
• 📎 Attachments — attach files directly from form inputs or File objects.
• 🛡️ Type-safe — full TypeScript support with normalised error handling.

How it fits together

There are three ways to use Postboi, from least to most explicit:

1. Zero-config send() — reads POSTBOI_PROVIDER and credentials from the environment. Best for apps where one provider is set per environment.
2. postboi/kit form actions — a one-line SvelteKit action that reads FormData, sends it, and returns a result.
3. A provider instance — new Resend({ ... }) when you want an explicit instance or you’re on a runtime without ambient env vars.

Start with the Quick start and let the CLI wire everything up for you, or set things up by hand with Manual setup.

Next steps