Stack0
Complete Email Platform

Transactional + marketing
in one SDK

Stop juggling multiple email services. Send transactional emails, build campaigns, automate sequences—all with a single TypeScript SDK.

send-email.ts
await stack0.mail.send({
  from: 'hello@yourdomain.com',
  to: 'user@example.com',
  subject: 'Welcome!',
  html: '<h1>Thanks for signing up!</h1>',
});
Start SendingView Documentation

$0.50 / 1,000 emails • Plans starting at $5/month

Capabilities

Everything in one place

No more stitching together multiple services for transactional and marketing email

Send

Single, batch, broadcast, and scheduled sending

Templates

Reusable templates with variable substitution

Campaigns

Create, schedule, and analyze email campaigns

Sequences

Automated drip campaigns and workflows

Analytics

Opens, clicks, bounces, and time series data

Transactional

Reliable transactional email

Password resets, order confirmations, notifications—delivered fast with full tracking. High deliverability backed by proper SPF, DKIM, and DMARC.

Welcome Email

Greet new users immediately after signup

typescript
await stack0.mail.send({
  from: 'hello@yourdomain.com',
  to: 'user@example.com',
  subject: 'Welcome to our app!',
  html: '<h1>Thanks for signing up!</h1>',
});

Password Reset

Secure password reset with unique tokens

typescript
await stack0.mail.send({
  from: 'security@yourdomain.com',
  to: user.email,
  templateId: 'password-reset',
  templateVariables: {
    resetLink: `https://app.com/reset/${token}`,
    expiresIn: '1 hour'
  },
});

Order Receipt

Transaction confirmations with order details

typescript
await stack0.mail.send({
  from: 'orders@yourdomain.com',
  to: customer.email,
  templateId: 'order-receipt',
  templateVariables: {
    orderId: order.id,
    total: order.total,
    items: order.items,
  },
});
Fast Delivery
Sub-second sending for time-sensitive emails
High Deliverability
Proper authentication and reputation management
Click Tracking
Track opens and clicks in real-time
Bounce Handling
Automatic suppression of invalid addresses
Marketing

Marketing without the bloat

Build audiences, send campaigns, automate sequences—all from the same API. No need for a separate marketing tool.

Audiences

Segment contacts into lists. Import in bulk, track subscription status, and manage preferences.

Campaigns

Design and schedule email campaigns. Target specific audiences with personalized content.

Sequences

Build automated email flows with timers, conditions, and event triggers. Visual flow builder included.

Events

Define custom events to trigger sequences. Track user behavior and automate responses.

trigger-sequence.ts
// Track event to trigger a sequence
await stack0.mail.events.track({
  eventName: 'purchase_completed',
  contactEmail: 'user@example.com',
  properties: {
    amount: 99.99,
    product_id: 'prod_123'
  },
});
 
// The sequence automatically:
// 1. Sends thank you email immediately
// 2. Waits 3 days
// 3. Sends review request
// 4. Waits 7 days
// 5. Sends upsell offer
Developer Experience

Built for developers

TypeScript-first, excellent types, intuitive API design

TypeScript-First SDK

Full type safety with autocomplete. Catch errors at compile time, not runtime.

Template Variables

Use {{name}}, {{company}}, or any variable in your templates. Preview with test data.

Webhook Events

Real-time notifications for delivery, opens, clicks, bounces, and complaints.

Analytics Dashboard

Track delivery rates, engagement metrics, and time series analytics in one place.

send-with-template.ts
// Send with template and variables
await stack0.mail.send({
  from: 'hello@yourdomain.com',
  to: 'user@example.com',
  templateId: 'welcome-email',
  templateVariables: {
    name: 'John',
    company: 'Acme Inc',
    loginUrl: 'https://app.acme.com/login'
  },
});
 
// Template: "Hi {{name}}, welcome to {{company}}!"
Domain Setup

Proper email authentication

We handle SPF, DKIM, and DMARC configuration for you. Just add a few DNS records and you're set for maximum deliverability.

SPF

Authorizes Stack0 to send on your behalf

v=spf1 include:stack0.dev ~all
DKIM

Cryptographic signature for email authenticity

CNAME record pointing to stack0.dev
DMARC

Policy for handling authentication failures

v=DMARC1; p=quarantine; rua=mailto:...

Verification takes minutes. Add DNS records, click verify, and start sending.

Migration

Coming from another provider?

If you're using Resend, you already know our API. Just change the import.

From Resend

Nearly identical API, same simplicity, plus marketing features

Before (Resend)

import { Resend } from 'resend'

const resend = new Resend(key)

await resend.emails.send({
  from: '...',
  to: '...',
  subject: '...',
  html: '...',
})

After (Stack0)

import { Stack0 } from '@stack0/sdk'

const stack0 = new Stack0({ apiKey })

await stack0.mail.send({
  from: '...',
  to: '...',
  subject: '...',
  html: '...',
})

From SendGrid

Simpler API, better DX, lower cost

Before (SendGrid)

sgMail.setApiKey(key)

await sgMail.send({
  to: '...',
  from: '...',
  subject: '...',
  text: '...',
  html: '...',
})

After (Stack0)

const stack0 = new Stack0({ apiKey })

await stack0.mail.send({
  from: '...',
  to: '...',
  subject: '...',
  html: '...',
})

Better than Resend

Same great DX, plus campaigns, sequences, and audiences built in.

Simpler than SendGrid

No enterprise bloat. Clean API, fair pricing, TypeScript-first.

Unified Platform

Works with CDN, Screenshots, and other Stack0 products. One SDK.

Pricing

Simple, usage-based pricing

Pay only for what you send. No hidden fees, no per-seat charges.

Email
$0.50/ 1,000 emails

Transactional & marketing. Inbound & outbound.

Transactional & marketing
Templates with variables
Campaigns & sequences
Full analytics & tracking
No monthly minimum
Get Started
Dedicated IP
Get your own dedicated IP address for better deliverability
$30/mo

Example usage costs

$5
10,000 emails/mo
$50
100,000 emails/mo
$500
1,000,000 emails/mo

Plans starting at $5/month. All features included.

Ready to simplify your email?

One SDK for transactional and marketing. No more juggling services.

Start SendingRead the Docs