Introduction

send0 is an API-first messaging infrastructure platform — the Stripe for Messaging. It gives developers a single, unified API to send messages across Email, WhatsApp, and SMS without stitching together multiple providers.

One API. Every channel. Delivered.

Why send0?

Most messaging infrastructure is fragmented. You need one provider for transactional email, another for WhatsApp, another for SMS — each with different APIs, dashboards, and billing models. send0 replaces all of that with a single integration.

• Unified API — One endpoint, one SDK, one dashboard for every channel.
• TypeScript SDK — First-class SDK with full type safety and auto-completion.
• Webhooks — Real-time delivery events pushed to your server.
• Templates — Reusable email templates with variable substitution.
• Test mode — Sandbox environment with sk_test_ keys. No real sends. Ever.
• AI-powered routing — Automatic channel optimisation per recipient (coming soon).

Current status

Base URL

All API requests are made to:

https://api.send0.dev/v1

Send your first email

Install the SDK and send an email in four lines of code.

import { Send0 } from 'send0';

const send0 = new Send0('sk_live_...');

await send0.emails.send({
  from: 'hello@yourdomain.com',
  to: 'user@example.com',
  subject: 'Welcome!',
  html: '<p>Hello from send0</p>',
});

That's it. No configuration files, no complex setup, no provider-specific logic.

Next steps

• Quickstart — Send your first email in under 5 minutes.
• Authentication — Learn about API key types and security.
• Error Handling — Understand error responses and handle them gracefully.

Key resources