Nexarion: MCP - A2A Universal Bridge

About the Project

As the AI ecosystem rapidly evolves, the methods by which agents communicate with each other and the outside world have become fragmented. Currently, two major standards dominate the industry: Anthropic’s MCP (Model Context Protocol), which provides a standard way to connect external tools and data sources to AI models; and Google’s A2A (Agent-to-Agent) protocol, which aims to distribute tasks and facilitate communication among different AI agents.

The biggest problem, however, is that these two massive ecosystems are isolated from each other. When developers try to run a Google A2A-based agent inside a Claude Desktop environment, they hit an incompatibility wall. Nexarion was designed exactly as a Universal Bridge to tear down this wall.

Nexarion provides a dynamic runtime that automatically analyzes A2A agents and instantly converts them into MCP-compatible tools. This allows developers to use any A2A agent directly inside Claude Desktop or Cursor IDE with zero configuration.

Comprehensive Features and Capabilities

• Dynamic Auto-Discovery: Simply provide Nexarion with an A2A agent’s endpoint. The system reads the agent’s manifesto, extracts all its capabilities and expected parameters, and instantly converts them into MCP-compliant JSON Schema tools.
• Real-Time Bidirectional Protocol Translation: It intercepts tools/call requests from MCP, translates them into the structured message/send format understood by A2A, and parses the complex responses and error states returned by the agent back into the standard MCP format.
• Streaming Support: To eliminate waiting times, especially for agents generating long text or performing phased analysis, Nexarion preserves and bridges the streaming (SSE / WebSockets) capabilities of both protocols.
• Plug-and-Play Claude Desktop Integration: By adding just a single line (the Nexarion executable path) to the Claude Desktop configuration file, you can access all your in-house or cloud-based A2A agents via native commands in Claude.
• VS Code and Web Dashboard Integration: Offers an integrated management panel where you can visually monitor agent connections, traffic logs, and translation errors.

Architecture and Technological Approach

Nexarion features a modular monorepo structure developed entirely with TypeScript. Thanks to its reliability and performance-oriented design, it operates with millisecond latency.

• Package Structure: The system consists of 8 main packages (@nexarion/core, @nexarion/server, @nexarion/sdk, @nexarion/registry, @nexarion/cli, @nexarion/web, @nexarion/vscode).
• Transport Layers: It supports both standard input/output (stdio) for direct IDE integration and HTTP/Server-Sent Events (SSE) transport layers for remote agents.
• Plugin Architecture: Developers can intercept the translation process to inject their own custom logging, authorization (auth), or data filtering logic.

Why Choose Nexarion?

It is the industry’s first and most comprehensive open-source solution to bridge MCP and A2A. While competitors generally require static configurations (hard-coded schemas), Nexarion’s self-discovery feature reduces the time to integrate a new agent from weeks to seconds. Its meticulous support for both protocols ensures 100% compatibility with zero feature loss.

Use Cases and Target Audience

• Individual Developers: Those who use tools like Claude Desktop as a personal assistant and want to automate their workflows with complex A2A agents in the background.
• Enterprise AI Teams: Companies looking to expose their custom-built A2A agents to the entire development team via standard MCP-supported tools (e.g., Cursor).
• AI Startups: Startups wanting to make their proprietary agents compatible with both the A2A and MCP ecosystems using a single codebase.

GitHub Repository: github.com/vahapogut/nexarion