How to Publish Your Library to npm

German CoccaFebruary 8, 2025About 2 min

How to Publish Your Library to npm 관련

In the world of JavaScript development, npm (Node Package Manager) has become an essential tool for managing dependencies and sharing reusable code. Whether you're building a simple website or a complex web application, npm libraries help streamline ...

How to Create an npm Library

Now that we’ve created our npm package, the next step is publishing it to the npm registry so others can install and use it. In this section, we’ll cover how to publish the package step by step.

Creating an npm Account

Before publishing, you need an npm account.

Go to https://npmjs.com/signup and create an account.
Verify your email address.

Step 2: Log in to npm from the Terminal

Run the following command in your terminal:

npm login

You will be prompted to enter:

Your npm username
Your password
Your email (associated with your npm account)

If the login is successful, you’ll see a message:

Logged in as your-username on https://registry.npmjs.org/

Configuring package.json for Publishing

Step 3: Ensure Your Package Name is Unique

Every npm package needs a unique name. Run the following command to check if your desired name is available:

npm search my-awesome-library

If the name is already taken, you’ll need to modify package.json and change the "name" field.

Step 4: Add Metadata and Keywords

Open package.json and ensure it includes useful metadata:

{
  "name": "my-awesome-library",
  "version": "1.0.0",
  "description": "A simple npm package for formatting dates",
  "main": "index.js",
  "repository": {
    "type": "git",
    "url": "https://github.com/yourusername/my-awesome-library.git"
  },
  "keywords": ["date", "formatter", "utility", "npm package"],
  "author": "Your Name <your-email@example.com>",
  "license": "MIT"
}

🔹 repository – Useful if you plan to host the project on GitHub.
🔹 keywords – Helps people discover your package on npm.
🔹 license – Specifies how others can use your package (for example, MIT, GPL, and so on).

Publishing the Package

Step 5: Publish Your Package to npm

Run the following command inside your project folder:

npm publish

If successful, you’ll see output similar to:

+ my-awesome-library@1.0.0

Your package is now available at:

📌 https://www.npmjs.com/package/my-awesome-library

Step 6: Making Changes and Updating the Package

If you want to release a new version, update the version field in package.json. npm follows Semantic Versioning (SemVer):

Patch: Bug fixes (1.0.0 → 1.0.1)
Minor: New features, backward-compatible (1.0.0 → 1.1.0)
Major: Breaking changes (1.0.0 → 2.0.0)

Instead of manually updating package.json, use:

npm version patch   # 1.0.0 → 1.0.1
npm version minor   # 1.0.0 → 1.1.0
npm version major   # 1.0.0 → 2.0.0

Then, publish the new version:

npm publish

If you accidentally publish a package and need to remove it:

npm unpublish my-awesome-library --force

Note

You can only unpublish packages within 72 hours of publishing.

🎯 You’ve successfully published your own npm library! Now, other developers can install it using:

npm install my-awesome-library

By following Semantic Versioning, writing clear documentation, and maintaining your package, you contribute to the open-source ecosystem and make your code reusable.