license-checker

What is license-checker?

The license-checker npm package is a tool that helps you manage and audit the licenses of the dependencies in your project. It provides detailed information about the licenses of all the packages in your node_modules directory, helping you ensure compliance with open-source license requirements.

What are license-checker's main functionalities?

List all licenses

This feature allows you to list all the licenses of the dependencies in your project. The code sample initializes the license-checker and prints out the licenses of all the packages found in the specified project directory.

const licenseChecker = require('license-checker');

licenseChecker.init({
  start: '/path/to/your/project'
}, function(err, packages) {
  if (err) {
    console.log(err);
  } else {
    console.log(packages);
  }
});

Filter by specific licenses

This feature allows you to filter the dependencies by specific licenses. The code sample initializes the license-checker and filters the packages to only include those with MIT or ISC licenses.

const licenseChecker = require('license-checker');

licenseChecker.init({
  start: '/path/to/your/project',
  onlyAllow: 'MIT;ISC'
}, function(err, packages) {
  if (err) {
    console.log(err);
  } else {
    console.log(packages);
  }
});

Custom format output

This feature allows you to customize the output format of the license information. The code sample initializes the license-checker and specifies a custom format for the output, including the name, version, licenses, and repository of each package.

const licenseChecker = require('license-checker');

licenseChecker.init({
  start: '/path/to/your/project',
  customFormat: {
    name: '',
    version: '',
    licenses: '',
    repository: ''
  }
}, function(err, packages) {
  if (err) {
    console.log(err);
  } else {
    console.log(packages);
  }
});

Other packages similar to license-checker

license-report

The license-report package provides a similar functionality to license-checker by generating a report of the licenses of the dependencies in your project. It offers a command-line interface and can output the report in various formats such as JSON, CSV, and plain text. Compared to license-checker, license-report focuses more on generating comprehensive reports.

npm-license-crawler

The npm-license-crawler package crawls through the dependencies of your project and generates a license report. It can be configured to include or exclude specific licenses and can output the report in JSON or CSV format. Compared to license-checker, npm-license-crawler provides more options for customizing the crawling process and the output format.

license-checker-webpack-plugin

The license-checker-webpack-plugin is a Webpack plugin that checks the licenses of the dependencies in your project during the build process. It integrates with Webpack and can be configured to fail the build if any disallowed licenses are found. Compared to license-checker, this package is specifically designed for use with Webpack and provides seamless integration with the build process.

README

NPM License Checker

Ever needed to see all the license info for a module and its dependencies?

It's this easy:

npm install -g license-checker

mkdir foo
cd foo
npm install yui-lint
license-checker

You should see something like this:

├─ cli@0.4.3
│  ├─ repository: http://github.com/chriso/cli
│  └─ licenses: MIT
├─ glob@3.1.14
│  ├─ repository: https://github.com/isaacs/node-glob
│  └─ licenses: UNKNOWN
├─ graceful-fs@1.1.14
│  ├─ repository: https://github.com/isaacs/node-graceful-fs
│  └─ licenses: UNKNOWN
├─ inherits@1.0.0
│  ├─ repository: https://github.com/isaacs/inherits
│  └─ licenses: UNKNOWN
├─ jshint@0.9.1
│  └─ licenses: MIT
├─ lru-cache@1.0.6
│  ├─ repository: https://github.com/isaacs/node-lru-cache
│  └─ licenses: MIT
├─ lru-cache@2.0.4
│  ├─ repository: https://github.com/isaacs/node-lru-cache
│  └─ licenses: MIT
├─ minimatch@0.0.5
│  ├─ repository: https://github.com/isaacs/minimatch
│  └─ licenses: MIT
├─ minimatch@0.2.9
│  ├─ repository: https://github.com/isaacs/minimatch
│  └─ licenses: MIT
├─ sigmund@1.0.0
│  ├─ repository: https://github.com/isaacs/sigmund
│  └─ licenses: UNKNOWN
└─ yui-lint@0.1.1
   ├─ licenses: BSD
      └─ repository: http://github.com/yui/yui-lint

An asterisk next to a license name means that it was deduced from an other file than package.json (README, LICENSE, COPYING, ...) You could see something like this:

└─ debug@2.0.0
   ├─ repository: https://github.com/visionmedia/debug
   └─ licenses: MIT*

Options

• --production only show production dependencies.
• --development only show development dependencies.
• --unknown report guessed licenses as unknown licenses.
• --onlyunknown only list packages with unknown or guessed licenses.
• --json output in json format.
• --csv output in csv format.
• --csvComponentPrefix prefix column for compoment in csv format.
• --out [filepath] write the data to a specific file.
• --customPath to add a custom Format file in JSON
• --exclude [list] exclude modules which licenses are in the comma-separated list from the output
• --relativeLicensePath output the location of the license files as relative paths
• --summary output a summary of the license usage',
• --failOn [list] fail (exit with code 1) on the first occurrence of the licenses of the comma-separated list

Exclusions

A list of licenses is the simplest way to describe what you want to exclude.

You can use valid SPDX identifiers. You can use valid SPDX expressions like MIT OR X11. You can use non-valid SPDX identifiers, like Public Domain, since npm does support some license strings that are not SPDX identifiers.

Examples

license-checker --json > /path/to/licenses.json
license-checker --csv --out /path/to/licenses.csv
license-checker --unknown
license-checker --customPath customFormatExample.json
license-checker --exclude 'MIT, MIT OR X11, BSD, ISC'
license-checker --onlyunknown

Custom format

The --customPath option can be used with CSV to specify the columns. Note that the first column, module_name, will always be used.

When used with JSON format, it will add the specified items to the usual ones.

The available items are the following:

• name
• version
• description
• repository
• publisher
• email
• url
• licenses
• licenseFile
• licenseText
• licenseModified

You can also give default values for each item. See an example in customFormatExample.json.

Requiring

var checker = require('license-checker');

checker.init({
    start: '/path/to/start/looking'
}, function(err, json) {
    if (err) {
        //Handle error
    } else {
        //The sorted json data
    }
});

Debugging

license-checker uses debug for internal logging. There’s two internal markers:

• license-checker:error for errors
• license-checker:log for non-errors

Set the DEBUG environment variable to one of these to see debug output:

$ export DEBUG=license-checker*; license-checker
scanning ./yui-lint
├─ cli@0.4.3
│  ├─ repository: http://github.com/chriso/cli
│  └─ licenses: MIT
# ...

How Licenses are Found

We walk through the node_modules directory with the read-installed module. Once we gathered a list of modules we walk through them and look at all of their package.json's, We try to identify the license with the spdx module to see if it has a valid SPDX license attached. If that fails, we then look into the module for the following files: LICENSE, LICENCE, COPYING, & README.

If one of the those files are found (in that order) we will attempt to parse the license data from it with a list of known license texts. This will be shown with the * next to the name of the license to show that we "guessed" at it.

Build Status

Changelog

v14.0.0 (2017/08/28 13:22 +00:00)

• b2a4403 14.0.0 (@davglass)
• #122 Added --failOn [list] mode (#122) (@tobilg)