websocket-mqtt

A zero-dependency MQTT over WebSocket client for JavaScript/TypeScript. Current stable version is 0.0.9 (beta, infrequent releases). Supports MQTT 3.1.1 with QoS 0 and 1, last will testament, and message callbacks. Differentiator: no external dependencies unlike mqtt.js, and ships TypeScript types. Lightweight alternative for simple MQTT-over-WebSocket use cases, but lacks MQTT 5, TLS in Node.js, and advanced features.