Introduction

Retransmit is a developer-first messaging platform: a single API and one balance for sending Email, SMS, WhatsApp, OTP, and other transactional communications.

One API. One balance. Every message.

You don’t create AWS, Twilio, or Meta accounts. You integrate Retransmit once, load credit, and start sending — Retransmit manages the underlying providers, routing, delivery, and infrastructure.

What’s available today

The first product is Retransmit Email:

Transactional email API (POST /v1/emails)
Official Node.js SDK — retransmit.dev on npm
API keys
Domain verification (SPF / DKIM)
Email logs and delivery status
Bounce and complaint handling
Webhooks with signed payloads

How the pieces fit


Your application
      │  Authorization: Bearer rt_...
      ▼
Retransmit API  ──►  Email / SMS / WhatsApp / OTP
      │
      ▼
Retransmit infrastructure (SES, Twilio, Meta, ...)

Where to go next

Quickstart — send your first email in a few minutes.
Domains — add and verify a sending domain.
API Reference — endpoints, authentication, and errors.
Webhooks — get notified about delivery events and verify signatures.

Environments

Environment	Base URL
Production	`https://api.retransmit.dev`
Local development (this monorepo)	`http://localhost:3002`

In local development, run the API with pnpm dev:api from the repository root (it starts on port 3002). The dashboard runs on port 3001 (pnpm dev:dashboard).