Crypto.org Chain JS library is a JavaScript SDK for interacting with the Crypto.org blockchain, enabling developers to manage private keys and key pairs, generate addresses, build and sign transactions, query the chain, and decode or encode transactions. The library is built with JavaScript/TypeScript and integrates with CosmJS for transaction broadcasting and chain queries, supporting features like offline signing, gas estimation, and Cosmos-compatible message handling. The project is maintained by Crypto.org and is currently in alpha development, with a clear warning that it should not be used in production systems.