Agent2Agent (A2A) Protocol Support

[willwashburn]

RFC

Summary

Add an optional @flue/a2a package that enables Flue agents to participate in the Agent2Agent (A2A) ecosystem, both as callable A2A agents and as clients of remote A2A agents.

The goal is to make Flue agents interoperable with the broader agent ecosystem without requiring changes to @flue/runtime.

Background & Motivation

First off, Flue is awesome.

As more agent frameworks emerge, one thing I'm wondering about is how Flue should think about agent-to-agent communication outside of the Flue ecosystem. Today, Flue agents can delegate to subagents through session.task(), but there's no standard way for external agents to discover or invoke them, nor for Flue agents to communicate with agents running elsewhere.

A2A seems to be gaining momentum as an interoperability protocol. If that trend continues, it would be nice for Flue agents to participate without introducing runtime dependencies or coupling Flue to any particular vendor or platform.

One thing I noticed while exploring the APIs is that Flue's dispatch() model is durable and asynchronous. A dispatched agent doesn't appear to create a workflow run that can later be retrieved via getRun(), which means an A2A integration would likely need its own task lifecycle mapping rather than assuming request/response execution.

Goals

• Allow Flue agents to be discovered and invoked by A2A-compatible clients.
• Allow Flue agents to discover and invoke remote A2A-compatible agents.
• Keep interoperability as an optional package rather than a runtime concern.
• Build entirely on top of public @flue/runtime APIs.
• Avoid introducing vendor-specific dependencies or lock-in.
• Establish a pattern for future protocol integrations.

Example

import { createA2AChannel } from '@flue/a2a';

export const channel = createA2AChannel({
  agent: 'support',
});

import { createAgent } from '@flue/runtime';
import { connectA2A } from '@flue/a2a';

export default createAgent(async () => ({
  tools: [
    await connectA2A(
      'https://example.com/.well-known/agent-card.json'
    ),
  ],
}));

[anselm94]

+1

More Enterprise AI Platforms are increasingly adopting A2A for agent interoperability. Other competing standards such as Agent Communication Protocol (ACP) merged with A2A (see announcement).

• A2A Protocol
• Official list of partners w/ links to announcements