learn-claude-code

learn-claude-code is an open course from shareAI-lab that teaches "harness engineering" by building a small Claude Code–like coding agent from scratch in Python. Its starting premise is that agency comes from the model, while a working agent product is the model plus a harness: the loop, tools, permissions, context management and coordination around it. The course builds that harness one mechanism at a time.

It suits developers who want to understand how coding agents work rather than just use them. The current track has 17 progressive lessons, each adding one mechanism with runnable code: the core agent loop with a single bash tool, adding tools, permission boundaries, hooks, planning with to-do lists, subagents, on-demand skill loading, context compaction, memory, a file-backed task graph, background jobs, scheduling, agent teams, MCP, an integrated runtime, resumable workflows and goal-driven continuation. Lessons have English, Chinese and Japanese text, and a web platform presents the course with source, simulator and architecture views. The course also takes a strong stance against drag-and-drop "agent" builders, which readers may or may not share.

Getting started: clone the repository, `pip install -r requirements.txt`, copy `.env.example` to `.env` with your `ANTHROPIC_API_KEY`, and run `python s01_agent_loop/code.py`. The web version runs with `npm install && npm run dev` in the `web` folder.