What Is an Agent Registry? (And What We Broke Before We Had One)

TL;DR An AI agent registry is a centralized catalog of every agent in your organization — what each agent does, what tools it can access, what version is running, who owns it, and how to call it It's to agents what a container registry is to Docker images or what a service mesh is to microservices — the layer that makes distributed components governable We hit the "which agents do we have?" wall at 14 agents across 3 teams. That's when the registry stopped being a nice-to-have About four months into our agentic AI buildout, our head of security asked a question I couldn't answer: "Can you give me a list of every AI agent running in production, what systems they have access to, and what version of each is currently deployed?" I had a rough mental model. I knew about the agents my team had built. I had a vague idea of what the data engineering team had shipped. The product team had recently added two agents I'd heard about secondhand. I spent the better part of a day pulling together a spreadsheet. By the time I finished, one of the agents I'd listed had already been replaced by a newer version. Two of them had been granted access to an internal API I hadn't known about. The spreadsheet was outdated before I sent it. That was our forcing function for building a proper agent registry. This post is what I wish I'd read before that conversation happened. What an agent registry is An agent registry is a centralized catalog of AI agents — a single source of truth that tracks every agent deployed in your organization, its capabilities, its integrations, its ownership, and its current state. The analogy that landed for me: it's to agents what a container registry (Docker Hub, ECR, GCR) is to container images. When you have three containers running, you don't need a registry — you know what you have. When you have 40 containers across six teams, you need a registry to know what's running, who owns it, what version is deployed, and what depends on what. Agents are the same. At