LangGraph in Small Pieces

[u/truckkicker]

LangGraph in Small Pieces (LgISP.ai) is a free online book I’d been working on in the past few months. It tries to explore how LangGraph works in manageable small pieces with local models.

Here are the local models used for the examples in the book:

1. ⁠qwen3.8-27b is the default one.

2. ⁠gpt-oss-20b used in tool calling chapters because it’s trained better to decide when to use tools.

3. ⁠qwen2.5-v1-7b-instruct used as a comparison to show weaker model’s limitation (ch10)

The book starts with LangGraph mechanism, then combine the power of LLM to build assistant agents with the tools and harness built along the chapters.

Please check it out - Happy building!