Transform inbound webhooks into delivered transactional emails in milliseconds
Turn events from Stripe, GitHub, Shopify, Clerk, or custom services into immediate customer alerts. Built for high-concurrency event loops with automated retries and dead-letter queues.
Drop into your application in under 60 seconds
Native typed interfaces with zero unnecessary dependencies. Built for standard fetch and modern edge runtimes.
import { SadaSend } from 'sadasend';
const sadasend = new SadaSend(process.env.SADASEND_API_KEY!);
export async function handleWebhookEvent(req: Request) {
const event = await req.json();
if (event.type === 'payment.succeeded') {
await sadasend.emails.send({
from: 'billing@yourdomain.com',
to: event.data.customer_email,
subject: `Payment Confirmation: $${(event.data.amount / 100).toFixed(2)}`,
html: `<p>Your payment of <strong>$${(event.data.amount / 100).toFixed(2)}</strong> was received.</p>`,
tags: ['webhook-event', event.type]
});
}
return new Response(JSON.stringify({ received: true }), { status: 200 });
}Engineered for high deliverability and zero incident risk
Every layer from edge connection pooling to per-key rate limits is designed to keep critical transactional dispatches fast, reliable, and contained.
High Concurrency Event Loops
Handles sudden traffic spikes and bulk webhook bursts without queuing bottlenecks or timeout failures.
Built-in Dead-Letter Queue (DLQ)
Monitor failed deliveries in the dashboard with 1-click retry mechanisms, ensuring zero lost messages from transient network glitches.
Cryptographic Signature Verification
Verify inbound and outbound webhook signatures with HMAC-SHA256 headers to prevent unauthorized event tampering.
low-latency Edge Ingestion
Respond to incoming webhook webhooks immediately, preventing third-party event dispatchers from triggering timeout retries.
SadaSend vs Traditional SMTP in Webhooks
Invoking blocking SMTP connections inside webhook handlers causes timeouts and dropped event retries. SadaSend REST dispatches in under 20ms.
| Feature & Capability | SadaSend | Traditional SMTP in Webhooks |
|---|---|---|
| Webhook Timeout Risk | Zero — a single HTTP response | High (SMTP handshakes > 1s) |
| Automatic Idempotency Key Guard | ||
| Dead-Letter Queue (DLQ) Inspector | ||
| Event Tagging & Filtering |
Start with 3,000 emails every month at zero cost
No artificial paywalls on security. Unlike legacy providers that reserve recipient allowlists or dedicated IP pools for high enterprise tiers, every SadaSend account receives full safety controls from day one.
Everything you need to know about webhook email API
Clear, transparent answers on deliverability, API authentication, and rate limits.
Related developer guides and architectural tutorials
Explore step-by-step production implementation blueprints, benchmarks, and protocols.
REST API Reference & Endpoints
Complete REST API reference for sending emails, managing API keys, tracking delivery events, and configuring recipient allowlists with low latency.
Official Client SDKs (TypeScript & Python)
Official zero-dependency client SDKs for SadaSend. TypeScript and Python packages are live on npm and PyPI with typed results and auto-idempotency.
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People assume transactional mail is exempt from filtering because it was requested. Mailbox providers do not know that, and mostly do not care.