Package Manager

What a Package Is

Almost every real project uses code that someone else wrote: things like the OpenAI SDK, a date formatting library, or a web framework. These reusable chunks of code are called packages (or libraries or modules, the terms are often interchangeable).

Writing everything from scratch would take forever. Package managers solve this by letting you install, update, and remove packages with a single command.

The Main Package Managers

• npm (Node Package Manager): the default package manager for JavaScript and Node.js. Run npm install openai to add the OpenAI library to your project.
• pip: Python's package manager. Run pip install openai to install the same library for Python projects.
• yarn and pnpm: alternatives to npm with some speed and reliability improvements; you'll see these in JavaScript projects too.

What Happens When You Install

When you run npm install openai, the package manager:

1. Looks up the package in its online registry
2. Downloads it along with any packages it depends on
3. Saves it to a local folder (node_modules for npm, site-packages for pip)
4. Records the version in a lockfile so the project is reproducible

Why This Matters for AI Development

Every AI SDK you'll ever use, OpenAI, Anthropic, LangChain, CrewAI, is installed via a package manager. Understanding npm install and pip install is a prerequisite for building anything with AI.