SDK

One package over the whole API (sending, templates, tracking, threads, drafts, labels, contacts, audiences, sign-up forms, broadcasts, domains, rules, webhooks, calendar, settings, roles, members, suppressions, files and disposable inboxes) with types for every request and response, two error classes, retries that cannot duplicate a send, and a webhook signature verifier. No runtime dependencies, ESM and CommonJS, on Node 20+, Bun, Deno and Cloudflare Workers. It carries a workspace key, so it runs on a server, and disposable inboxes are the one part that also runs in a browser.

pnpm add @nextmail/sdk

import { init, nextmail } from '@nextmail/sdk' init({ apiKey: process.env.NEXTMAIL_API_KEY }) await nextmail.emails.send({  from: 'Acme Billing <billing@acme.com>',  to: 'ada@example.com',  subject: 'Your September invoice',  html: '<p>Invoice attached.</p>',})

Everything here is the same surface the API reference documents, so read that for what an endpoint does and this for how to call it. There is one method for every documented operation, and the package's parity check reads the OpenAPI document to prove it.