LangChain Q&A Bot, Internal LLM Spike

Overview

A small internal build building a question-answering bot in Node.js with LangChain.js and OpenAI. A single-commit spike used to validate the JavaScript LLM tooling and structured-output workflow.

Why It Exists

An early-stage exploration to get hands-on with LangChain.js, OpenAI’s Node SDK, and Zod-based structured output, establishing internal familiarity with the JS LLM stack rather than shipping a product.

What We Built

A minimal Node.js (ESM) project wiring LangChain ^0.0.202, the OpenAI SDK ^4, dotenv for configuration, and zod for schema-validated responses. Scope is intentionally small, a focused Q&A spike.

Technologies & Approach

JavaScript/Node with LangChain.js and OpenAI; Zod for typed, validated LLM output. Chosen to evaluate the JS-side LLM ecosystem as an alternative to the Python tooling used elsewhere.

Outcome / Impact

A throwaway-scale spike that confirmed the LangChain.js + OpenAI + Zod workflow and seeded the studio’s JavaScript LLM capability. Honestly framed as R&D, not production.

Capabilities Demonstrated

• Rapid LLM building in Node.js
• LangChain.js + OpenAI integration
• Schema-validated structured LLM output (Zod)