Vonage Client SDK (Legacy Nexmo Client)

The `nexmo-client` package provides a JavaScript SDK for integrating programmable conversation features, including in-app messaging and voice, into web and Node.js applications. While the package name is `nexmo-client`, it is functionally the predecessor to the Vonage Client SDK. The current stable version, 9.6.1, was last published over a year ago (as of 2026), indicating it is in a deprecated or maintenance state, with active development having shifted to the official `@vonage/client-sdk` package. It offers capabilities like offline message synchronization, push notifications, rich text and image support for messaging, and advanced in-app voice features such as group calling and user controls. Its primary differentiators lie in enabling robust real-time communication within applications through the Vonage API platform.