# LangChain Hello World: One-Stop Framework Building Applications with LLMs

[Understand Concepts](https://docs.langchain.com/docs/)

Create a Node.js TypeScript Project.

[What is .env ? How to Set up and run a .env file in Node?](https://www.codementor.io/@parthibakumarmurugesan/what-is-env-how-to-set-up-and-run-a-env-file-in-node-1pnyxw9yxj)

    npm i dotenv
    npm i --save-dev @types/node

[Read Quick Start Setup and installation](https://js.langchain.com/docs/getting-started/install)

    npm install -S langchain

[Quickstart, using LLMs](https://js.langchain.com/docs/getting-started/guide-llm)

Rename the file .env.example to .env and update the keys which you get from [OpenAI website](https://platform.openai.com/account/api-keys)


[Temperature](https://gptforwork.com/guides/openai-gpt3-temperature)



References:

[Langchain Javascript Coding Tutorial | Getting Started | Node.js Quickstart](https://www.youtube.com/watch?v=zAnf6PPnvLg)

[Langchain Tutorial For Typescript and Javascript Developers](https://github.com/mayooear/langchain-js-tutorial)


[LangChainJS Support for Multiple JS Environments](https://blog.langchain.dev/js-envs/)