LangChain.rb — Chains, Agents, and Memory for Ruby AI Apps

This is post #21 in the Ruby for AI series. We've been building everything from scratch — API calls, RAG pipelines, agents, streaming. That's great for understanding. But sometimes you want a framework that handles the plumbing. Enter LangChain.rb — Ruby's port of the popular LangChain library. What Is LangChain.rb? LangChain.rb gives you pre-built abstractions for common AI patterns: LLM clients, prompt templates, chains, vector search, agents, and conversation memory. Instead of wi...