Open Source Protocols
Protocols define shared rules for exchanging data and coordinating behavior between software systems. They help independent applications, services, and devices communicate reliably by specifying message formats, connection steps, error handling, and security expectations. Clear protocol definitions reduce ambiguity, support interoperability, and make it easier to build compatible implementations across languages and platforms.
Open source resources in this area include protocol specifications, reference implementations, client and server libraries, schemas, and conformance or testing tools. When choosing one, consider its maturity, license, maintenance activity, security model, documentation, and compatibility with your existing systems. Protocols are useful to developers integrating services, teams building distributed applications, and organizations seeking standards-based communication without dependence on a single vendor.
5 repositories · updated August 21, 2026
awesome-a2a: A Curated List of Agent2Agent (A2A) Resources
The awesome-a2a repository is a comprehensive, curated list of Agent2Agent (A2A) protocol servers, clients, tools, and frameworks. It serves as a central hub for developers looking to explore and build interoperable AI agent systems. This resource helps in discovering various A2A-compliant implementations and related utilities.
ext-apps: Standard for UIs Embedded in AI Chatbots with MCP Protocol
MCP Apps provides a standardized way to deliver interactive UIs from MCP servers, rendering inline in compliant chat clients like Claude and ChatGPT. This repository contains the official specification and SDK for building these interactive UIs. It enables developers to create rich user experiences, such as charts, forms, and dashboards, directly within AI chatbot conversations.
UTCP Specification: A Standard for Universal Tool Calling
The `utcp-specification` repository hosts the official documentation for the Universal Tool Calling Protocol (UTCP). This protocol provides a modern, flexible, and scalable standard for AI systems and clients to discover and interact with tools across various communication protocols. It aims to standardize tool discovery, call formats, authentication, and error handling for enhanced interoperability.
Model Context Protocol: Specification and Documentation
The Model Context Protocol (MCP) repository provides the official specification and documentation for this crucial protocol. It defines the MCP protocol schema in TypeScript, also making it available as JSON Schema for broad compatibility. This project aims to standardize how models interact with their context, fostering interoperability across various systems.
Linera Protocol: Scalable Decentralized Blockchain Infrastructure
Linera Protocol is a cutting-edge decentralized blockchain infrastructure designed for highly scalable, secure, and low-latency Web3 applications. Built primarily with Rust and leveraging WebAssembly, it provides a robust framework for developing next-generation decentralized applications. With a strong focus on performance, Linera aims to address common scalability challenges in the blockchain space.