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 🆔…