The Architecture of a Self-Hosted AI Gateway

Most tutorials tell you how to set up a tool. This article is about why it's designed the way it is. OpenClaw is an open-source AI agent gateway — a self-hosted system that connects chat platforms to AI models. When I first looked at its architecture, several design decisions stood out as non-obvious. They reflect trade-offs that anyone building AI infrastructure will eventually face. Let me unpack the ones that matter. The Core Constraint: One Gateway Per Host The first thing you notice about OpenClaw's architecture is a hard constraint: one Gateway process per host. No horizontal scaling. No load balancer in front of multiple instances. This seems limiting until you understand why. The Gateway maintains stateful connections to chat platforms. A WhatsApp session is tied to a specific device pairing — you scan a QR code, and that session is bound to this process on this machine. A Telegram bot runs a long-polling connection that expects exactly one consumer. Running two Gateway instanc