Gravity SMS Docs

Overview

Gravity SMS is a REST API that enables you to send and receive SMS messages through your RingCentral account. Sign up at app.gravitysms.com, connect your RingCentral account, create an app to get your API key, and start sending messages.

Who is this for

Developers building applications that need programmatic SMS — CRM integrations, appointment reminders, notification services, and custom apps that send or receive text messages via a simple REST API.

Non-technical users connecting SMS to business workflows through Power Automate, Zapier, or Make — no coding required.

How it works

The gateway sits between your application and RingCentral. Instead of integrating directly with the RingCentral SDK, your app sends simple REST requests to the gateway.

  1. Sign up — Create your account at app.gravitysms.com. Your workspace is set up automatically.
  2. Connect RingCentral — Click Connect RingCentral in your dashboard to authorize the gateway to use your RingCentral account via OAuth.
  3. Create an app — Create an app in the dashboard to generate your API key.
  4. Send and receive SMS — Use the REST API directly, or connect through Power Automate, Zapier, or Make. Receive inbound SMS via webhooks or WebSocket.

Capabilities

REST API

Send SMS, check delivery status, query message history, manage apps and tenants.

WebSocket

Real-time delivery status updates and inbound SMS notifications over a persistent connection.

Webhook delivery

Inbound SMS messages are forwarded to your app via HTTP POST to a URL you configure.

Multi-tenancy

Your account data, credentials, and phone numbers are fully isolated. Create multiple apps under a single account.

Architecture

The gateway queues outbound messages and delivers them asynchronously with automatic retries and per-number rate limiting. Inbound SMS from RingCentral is forwarded to your app via webhooks or WebSocket in real time.

RingCentral dependency
You must connect a RingCentral account before sending or receiving SMS. The gateway does not provide phone numbers directly — it uses the numbers from your RingCentral account.

Related docs