Introduction
The Lotus JS Client is a collection of small JavaScript libraries that you can use to communicate with the Lotus implementation of Filecoin via it's JSON-RPC API.
The Lotus daemons exposes JSON-RPC methods via HTTP and WebSockets that can be called from any language. Applications and websites written in JavaScript can make calls to the endpoints directly using the raw JSON-RPC API, or they can use these libraries to make accessing the APIs more convenient and ergonomic from common JavaScript environments.
For more information on other libraries and languages, and for basic information on how to build applications for Filecoin, check out the "Build" documentation on docs.filecoin.io.