23r3

23r3 is a protocol and reference implementation for secure remote procedure calls in distributed systems. It provides bidirectional, low-latency communication with support for streaming and pluggable authentication, aiming to be modular and cross-language friendly.

Its technical design centers on a compact binary framing layer that runs over TLS 1.3 or equivalent, with multiplexed streams and a flexible capability negotiation mechanism. A pluggable serializer layer allows the use of JSON-RPC 2.0, MessagePack-RPC, or custom encodings without changing the core protocol. The protocol also includes a coherent error model and built-in support for deadlines and cancellation.

Development of 23r3 emerged from community discussions in the early 2020s, with public repositories and governance focused on transparency and backward compatibility. Reference implementations exist in multiple languages, including Go, Rust, and Python.

Common use cases include microservices, cloud-edge architectures, and IoT deployments that require secure, reliable remote procedure calls with streaming capabilities and observability hooks.

Adoption is modest but growing among open-source projects and research teams. Critics point to added complexity and interoperability considerations when compared with more established protocols, while proponents cite tighter security assumptions and better performance in streaming scenarios. The project continues to pursue standardization efforts and broader language support.