Autonomous Task Agents: Manus and CodeAct

Coding agents like Claude Code and Codex are tuned for software work in a repo. Manus is a more general autonomous agent: give it a goal ("research this topic and write a report," "build and deploy a small website") and it runs end to end in a cloud sandbox, browsing the web, writing and running code, and producing real deliverables. It is a great capstone case study because it combines almost everything from earlier chapters (the loop, tools, sandbox, memory, planning, multi-agent) and adds two distinctive ideas worth stealing: CodeAct and file-based memory. Most of what follows comes from a reverse-engineering report based on Manus's leaked system prompt and the CodeAct research paper it cites.