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.