Email Connector — Open Source SDK & Embeddable UI

The open-source, zero-trust transactional email failover balancer and embeddable UI control plane for modern applications.

Stack 5+ free email tiers to dispatch ~24,000 free transactional emails every month (~800/day) with zero data egress, zero vendor lock-in, and automatic priority cascading across Resend, Brevo, Mailjet, MailerSend, and SendGrid.

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🌟 Why Email Connector?

1. Stack ~24,000 Free Emails / Month: By cascading Tier-1 provider free allowances (Brevo 300/day, Mailjet 200/day, Resend 100/day, SendGrid 100/day, MailerSend 100/day), your application gets enterprise-grade volume for $0/mo.
2. Mode A Zero-Trust Runtime: Your API keys and email message bodies remain strictly in-process memory on your servers. Zero email data or credentials pass through any external intermediary relay.
3. Priority Cascading (1 to 5): Automatically routes to backup providers on HTTP 429 rate limits, quota exhaustion, 5xx server errors, or connection timeouts.
4. Drop-in Embeddable UI: Drop an enterprise-grade "Sending Servers" management screen directly into your SaaS using @emailconnector/react.

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📦 Packages in this Repository

Package	Version	Description
@emailconnector/sdk	1.0.0	In-process Zero-Trust load-balancer, token bucket rate limiter, and 25+ ESP drivers.
@emailconnector/react	1.0.0	Embeddable React sending server management tables, live quota gauges, and add server modals.
@emailconnector/config-schema	1.0.0	Shared Zod schemas, validation contracts, and TypeScript types.

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🚀 Quickstart: Zero-Trust SDK (@emailconnector/sdk)

1. Installation

Option A: Direct from GitHub (Works Today — No npm registry wait!)

Install and use @emailconnector/sdk directly from GitHub today without waiting for npm publication:

# Direct install from GitHub (automatically links as @emailconnector/sdk)
npm install git+https://github.com/LaunchLiveHQ/email-connector.git

Or explicitly named:

npm install @emailconnector/sdk@git+https://github.com/LaunchLiveHQ/email-connector.git

With other package managers:

# pnpm
pnpm add @emailconnector/sdk@git+https://github.com/LaunchLiveHQ/email-connector.git

# Yarn
yarn add @emailconnector/sdk@git+https://github.com/LaunchLiveHQ/email-connector.git

# Bun
bun add @emailconnector/sdk@git+https://github.com/LaunchLiveHQ/email-connector.git

Option B: Standard npm Registry (When published)

npm install @emailconnector/sdk

2. Configuration & Sending

import { ZeroTrustBalancer } from "@emailconnector/sdk";

// Configure your sending servers in priority order (1 to 5)
const balancer = new ZeroTrustBalancer({
  servers: [
    {
      id: "resend-primary",
      provider: "resend",
      apiKey: process.env.RESEND_API_KEY!,
      priority: 1,
      dailyLimit: 100,
      status: "active",
    },
    {
      id: "brevo-fallback",
      provider: "brevo",
      apiKey: process.env.BREVO_API_KEY!,
      priority: 2,
      dailyLimit: 300,
      status: "active",
    },
    {
      id: "mailjet-backup",
      provider: "mailjet",
      apiKey: process.env.MAILJET_API_KEY!,
      apiSecret: process.env.MAILJET_API_SECRET!,
      priority: 3,
      dailyLimit: 200,
      status: "active",
    },
  ],
});

// Dispatches directly via Resend.
// If Resend hits 100 emails/day or returns 429, automatically fails over to Brevo!
const response = await balancer.sendEmail({
  from: "notifications@yourdomain.com",
  to: "customer@example.com",
  subject: "Your Order Confirmation #8201",
  html: "<p>Thank you for your order!</p>",
  text: "Thank you for your order!",
});

console.log(`Dispatched via: ${response.provider} (Status: ${response.status})`);

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🎨 Embeddable UI Component: (@emailconnector/react)

Drop an enterprise-grade Sending Servers control plane into your SaaS settings screen in seconds:

# npm registry (when published)
npm install @emailconnector/react

Note for Direct GitHub Install: If you installed via git+https://github.com/LaunchLiveHQ/email-connector.git, you can import all components directly from @emailconnector/sdk/react without a separate package installation!

"use client";

import React, { useState } from "react";
import {
  EmailConnectionProvider,
  SendingServersTable,
  AddServerModal,
  QuotaGaugeCard,
} from "@emailconnector/react";

export default function EmailSettingsScreen() {
  const [isModalOpen, setIsModalOpen] = useState(false);

  return (
    <EmailConnectionProvider>
      <div className="max-w-5xl mx-auto p-8 space-y-6">
        <div className="flex items-center justify-between">
          <div>
            <h1 className="text-2xl font-bold">Email Routing & Failover</h1>
            <p className="text-sm text-slate-500">Configure zero-trust priority cascades and monitor daily caps.</p>
          </div>
          <button
            onClick={() => setIsModalOpen(true)}
            className="px-4 py-2 bg-emerald-600 text-white rounded-xl text-sm font-semibold"
          >
            + Connect Server
          </button>
        </div>

        {/* Live Pooled Quota Gauge */}
        <QuotaGaugeCard />

        {/* Interactive Priority Management Table */}
        <SendingServersTable />

        {/* Add Server Modal with Pre-flight Connection Testing */}
        <AddServerModal isOpen={isModalOpen} onClose={() => setIsModalOpen(false)} />
      </div>
    </EmailConnectionProvider>
  );
}

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📊 Supported Drivers & Providers

• Core Freemium Pool: Resend, Brevo (Sendinblue), Mailjet, MailerSend, Twilio SendGrid
• Enterprise & Cloud: Amazon SES, Postmark, ZeptoMail (Zoho), Cloudflare Email Routing
• Universal Standards: Standard SMTP / TLS

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📄 License

This open-source repository is licensed under the Apache License, Version 2.0 — see the LICENSE file for details.

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Maintained with ❤️ by LaunchLiveHQ • Platform & Marketplace: email-connector.com