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High-Throughput Bun RuntimeNative Bun.serve & Fetch

Ultra-fast transactional email for Bun runtimes with native global fetch

Zero-dependency, high-throughput email dispatch built specifically for Bun. Dispatch thousands of transactional messages per second with low latency.

3,000 emails/month freeZero credit card requiredSub-20ms edge latency
10,000+ req/s
Throughput
Bun native fetch
No cold start
Startup Time
Long-lived process, not a lambda
6,000 / mo
Free Tier
Emails included free
Developer Ergonomics

Drop into your application in under 60 seconds

Native typed interfaces with zero unnecessary dependencies. Built for standard fetch and modern edge runtimes.

$bun add sadasend
server.ts
typescript
TYPESCRIPT
import { SadaSend } from 'sadasend';

const sadasend = new SadaSend(Bun.env.SADASEND_API_KEY);

Bun.serve({
  port: 6000,
  async fetch(req) {
    if (req.method === 'POST' && new URL(req.url).pathname === '/send') {
      const { to, subject, html } = await req.json();

      const result = await sadasend.emails.send({
        from: 'alerts@yourdomain.com',
        to,
        subject,
        html,
      });

      return Response.json({ success: true, id: result.id });
    }
    return new Response('Not Found', { status: 404 });
  },
});

console.log('Bun HTTP server running on port 6000');

Pure TypeScript server for Bun using native Bun.serve and zero external C-bindings or heavyweight shims.

Core Infrastructure

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.

Engineered for Bun Fast Engine

Maximizes Bun high-speed HTTP dispatch, achieving thousands of requests per second.

Zero C-Binding Dependencies

Pure TypeScript and native global fetch eliminates crashes from incompatible Node-gyp C++ addons.

Native Bun.env Integration

Automatically loads environment variables from .env files without requiring dotenv.

Microsecond Cold Starts

Instant execution on edge nodes and containerized microservices without module loading lag.

Full TypeScript Support

Native .ts file execution out of the box with zero compilation or transpile steps required.

RFC 8058 Automatic Headers

Compliant List-Unsubscribe headers injected seamlessly on all outbound emails.

Architectural Comparison

SadaSend vs Node.js + Legacy SMTP Libraries

Compare Bun ultra-fast native HTTP architecture against legacy Node.js mailers.

Feature & CapabilitySadaSendNode.js + Legacy SMTP Libraries
Native Global Fetch ArchitectureHeavy socket wrappers
Runtime Cold Start TimeNo cold start (Bun native)150 - 500ms (Node.js)
Zero C-Binding DependenciesVulnerable to build errors
Per-Key Staging Allowlists
Hosted MCP Tool Integration
Free Monthly Tier6,000 sends foreverTrial only
Forever Free Tier
Transparent Economics

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.

3,000 dispatches monthly forever with zero credit card
All safety gates, allowlists, and velocity limits included
Scale seamlessly: Starter ($12/mo for 10k), Pro ($19/mo for 50k), Scale ($79/mo for 250k)
Free Developer Plan
$0 / mo

No credit card required

Create Free AccountCompare all paid plan tiers
Frequently Asked Questions

Everything you need to know about Bun email API

Clear, transparent answers on deliverability, API authentication, and rate limits.

Yes! SadaSend works natively in Bun with zero polyfills or compilation steps. Install with bun add sadasend and use immediately.
Technical Deep Dives

Related developer guides and architectural tutorials

Explore step-by-step production implementation blueprints, benchmarks, and protocols.

Documentation

REST API Reference & Endpoints

Complete REST API reference for sending emails, managing API keys, tracking delivery events, and configuring recipient allowlists with low latency.

Read guide
Documentation

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.

Read guide
Documentation

API Error Codes & Troubleshooting

HTTP status codes, machine-readable error reasons, and step-by-step remediation guides for API key rate limits, circuit breakers, and bounce handling.

Read guide
Deep Dive3 min read

How to Send Transactional Email with Bun and TypeScript (Zero Dependencies)

Stop wrestling with bloated Node.js polyfills. Learn how to send transactional emails in Bun with sub-millisecond cold starts and full TypeScript type safety.

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The worst bug an email service can have is not a crash. It is accepting a message, returning 202, and never sending it.

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Nodemailer vs Native Fetch in 2026: Why Modern Runtimes Abandoned Legacy SMTP

Nodemailer served the Node.js ecosystem for 15 years. Here is why modern serverless and edge runtimes have replaced raw SMTP libraries with native fetch.

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FastAPI & Python 3.12 Email Agent with Pydantic Validation

FastAPI and Pydantic v2 provide unmatched performance for Python backends. Learn how to build an async transactional email microservice with allowlist guards.

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Why your transactional email goes to spam

People assume transactional mail is exempt from filtering because it was requested. Mailbox providers do not know that, and mostly do not care.

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