#langchain
All the articles tagged with "langchain".
- 16 min read
LangChain and LangGraph middleware: seven small lessons
Middleware lets you run your own code around an agent's model and tool calls. Seven tiny Node.js lessons in one file: logging, timing, retries, tool errors, call limits, dynamic models, and run order.
- 17 min read
LangGraph graphs explained: eight small lessons
A graph is just state, nodes and edges. Eight tiny Node.js lessons, with flowcharts for each one: linear, branching, loops, parallel, chat messages, and a full agent graph you build by hand.
- 13 min read
Tool calling from scratch with LangChain and Node.js
A model on its own can only write text. Tools let it do real things. Ten tiny Node.js lessons, with flowcharts: your first tool, the tool-calling loop, many tools, parallel calls, error handling, and building the loop by hand with LangGraph.
- 31 min read
LangChain Cheat Sheet for Node.js, TypeScript and pgvector
The LangChain.js functions and methods you'll use most, each with a small working example: chat models, prompts, embeddings, PGVectorStore, retrievers, RAG, tools, agents, structured output, memory and streaming.