Get Started with Langchain JS

a basic node.js template to run langchain.js

How to use this template

All you need to do is

1. add your OpenAI API key to the .env file OPENAI_API_KEY=YOUR-KEY and

2. run the app with the following command

npm install && npm run dev 

After that, you can edit the app.ts file to change the prompt.

app.ts uses langchain with OpenAI to generate a code snippet, format the response, and save the output (a complete react component) to a file.

How this template was built

1. install dependencies

npm init es6 -y && npm install langchain openai dotenv @types/node

2. setup node project

typescript ts-node 

npx tsc --init --rootDir src --outDir ./dist --esModuleInterop --lib ES2020 --target ES2020 --module nodenext --noImplicitAny true

3. Update Package.json

  "scripts": { 
      "build": "tsc", 
      "start": "node ./dist/app.js", 
      "dev": "ts-node --esm ./src/app.ts"
  },

4. Create app.ts in the src folder.

mkdir src 
echo "console.log('Welcome to the LangChain.js tutorial by LangChainers.')" > src/app.ts

5. boot up

npm run build
npm run start

I followed this Blog post tutorial to setup the initial node environment.