Prerequisites
Vonage Client SDK provides programmable voice calling across Android, iOS, and Web. This section gets you from a new account to the minimum setup required for your first call flow.
Platform Requirements
Before starting, verify your target platform meets the minimum requirements:
| Platform | Minimum Version | Key Permission |
|---|---|---|
| Android | SDK 23 (Android 6.0) | INTERNET, RECORD_AUDIO (runtime) |
| iOS | iOS 15.0 | Microphone (NSMicrophoneUsageDescription) |
| Web | Chrome 70+, Firefox 60+, Safari 14.1+, Edge 79+ | Microphone (browser-prompted) |
All platforms require WebRTC support. The SDK will not function on older OS versions or browsers that lack WebRTC APIs.
Warning: On Android, RECORD_AUDIO is a dangerous permission requiring runtime consent before any call. On iOS, you must include the NSMicrophoneUsageDescription key in your Info.plist or the app will crash when requesting microphone access. On Web, the browser prompts the user automatically — no manifest entry is needed, but the call will have no audio if the user denies access.
Account Setup
- If you do not have one already, sign up for a Vonage account.
- Create a new Vonage application.
- Download and store your generated private key securely.
- Copy and save your API key & Application ID.
- Optionally, buy a virtual number if you want to test PSTN inbound scenarios.
Voice Backend Requirement
To place or receive calls, your application needs a backend that can:
- mint user JWTs for authenticated sessions
- expose a public answer webhook that returns valid NCCO