Google's A2A Protocol Is Great — Here's What I Learned Building the Same Thing Myself First

Google's Agent2Agent (A2A) Protocol launched with 50+ enterprise partners. It's a serious, well-designed spec for agent interoperability. But sometimes the best way to understand a protocol is to build something similar before reading the spec — then compare notes. I built Agent Exchange Hub — a minimal agent registry — before studying A2A in depth. Looking at them side by side is illuminating. Here's what I got right, what I got wrong, and what neither of us has figured out yet. What A2A is actually solving A2A addresses a real gap: agents from different vendors (LangChain, AutoGen, CrewAI, custom) can't discover or delegate to each other. They're siloed. The spec defines: Agent Cards — JSON descriptors (capabilities, endpoints, auth requirements) Tasks — the unit of work exchanged between agents Streaming — SSE-based updates for long-running tasks Push notifications — webhook callbacks It layers on top of HTTPS + OAuth, assuming agents are stateful services with persistent endpoints.