What Nobody Tells You About Building a Protocol for AI Agents

For the past few months, I've been building ARSIA Protocol as a part-time open source project, an open compliance layer for AI agents, designed to sit above MCP (Anthropic) and A2A (Google). The first ideas came in July 2025. Back then it was just a question: what if there was a compliance layer that sat above agent communication protocols? For months, that's all it was, an idea slowly taking shape. I'd study the regulatory landscape, read the EU AI Act, sketch mental models, scribble notes. Weekend conversations about what the architecture could look like. No code, no repo, no rush. The idea needed time to mature, and I let it. By November I had rough concept drafts. By January the mental model was solid enough to start testing assumptions on paper. But it wasn't until March 2026, with the architecture firmly settled in my head, that I sat down and wrote the first real draft of the specification. That incubation period of seven months of thinking before building turned out to be one o