OneSignal

About OneSignal

OneSignal provides a REST API for sending push notifications, email, and SMS messages, as well as managing users, subscriptions, segments, and message templates. The API supports creating and updating templates for push, email, and SMS content, and lets developers record custom events to trigger Journeys and Wait Until nodes. It also supports Live Activity updates for iOS devices.

Beyond messaging, the API covers user and subscription management (creating, viewing, updating, and deleting users), segment creation and filtering for targeted messaging, and data export in CSV format for subscriptions and events (sent, received, clicked). It also provides endpoints for managing apps (grouping platforms like mobile apps and websites under a single App ID) and for creating, viewing, updating, and deleting API keys with specific permissions.

All requests require HTTPS with TLS 1.2 or higher over port 443, and traffic is routed through Cloudflare's global edge network. The API returns temporary errors such as 429 (rate limited) or 5xx (server errors), and OneSignal recommends using an idempotency key with retries to avoid duplicate messages; the default API response timeout is 100 seconds. This API is intended for developers integrating messaging and user-data functionality into their applications.

Key features

• Send push notifications, email, and SMS via REST API
• Create and manage Users and Subscriptions with tags and aliases
• Build Segments with filters for targeted messaging
• Create reusable templates for push, email, and SMS messages
• Track custom events to trigger Journeys
• Export CSV data for subscriptions and events

Frequently asked questions