A complete, actionable build guide derived from a deep read of multica-ai/multica (~22k stars, ~42 MB, dual-language Go + TypeScript monorepo). If you read only one section before coding, read §3 The Core Idea and §5 The Agent Backend Interface . Everything else hangs off those two ideas. 📋 Table of Contents 🧐 What Multica Is — and What It Is Not ⚡ The 30-Second Mental Model 💡 The Core Idea — Don't Build the Agent Loop, Wrap It 🏗️ Architecture at a Glance 4.1 🌐 Process / Service Topology 4.2 📂 Repo Layout (top-level) 4.3 ⚙️ Tech Stack (the load-bearing pieces) 🔌 The Agent Backend Interface (the keystone abstraction) 5.1 🔗 The Interface 5.2 🏭 The Factory 5.3 📐 The Canonical Implementation Pattern (Claude Code) 5.4 🔍 Per-Backend Quirks Worth Knowing 5.5 🏆 Why This Design Wins 🔄 The Local Daemon — Polling, Wakeups, Concurrency 6.1 🔄 Lifecycle ( Daemon.Run ) 6.2 🔁 The Poll Loop 6.3 ⚙️ Per-Task Pipeline ( handleTask → runTask ) 6.4 🔎 Auto-Detection of Installed CLIs 6.5 🆔 Stable Daemon ID 6.6 👤…