CLI Agent Orchestrator (CAO) is an open-source, lightweight orchestration system from AWS Labs for managing multiple AI coding agent sessions in tmux terminals. It implements a hierarchical multi-agent architecture where a supervisor agent delegates tasks to specialized worker agents (developer, reviewer, etc.) via three orchestration patterns: Handoff (synchronous), Assign (asynchronous/parallel), and Send Message (direct communication). CAO supports seven AI coding CLI providers including Claude Code, Codex CLI, Gemini CLI, GitHub Copilot CLI, Kiro CLI, Kimi CLI, and Amazon Q Developer. Key features include session-based isolation, cross-provider orchestration, tool restrictions per agent role, scheduled flows via cron expressions, a web dashboard UI, and a local MCP server for inter-agent communication. Installation requires Python 3.10+, tmux 3.3+, and the uv package manager.