Jayson JSON-RPC Server and Client

Jayson is a comprehensive JavaScript library providing both server and client implementations for the JSON-RPC 2.0 and 1.0 specifications. It enables developers to build robust remote procedure call systems over HTTP, HTTPS, TCP, TLS, and WebSockets connections, primarily targeting Node.js environments. The current stable version is 4.3.0. The project maintains an active development pace with ongoing bug fixes and feature enhancements, though major version releases are not on a fixed cadence. Key differentiators include its support for simultaneous server interfaces, relaying requests, flexible method routing, transparent serialization using revivers/replacers, and first-class Promises support, making it suitable for complex distributed systems and microservices architectures. It also ships with full TypeScript type definitions since v2.1.0.