• NPM License Checker
  • Table of Contents
  • Introduction
  • Changes
    • Version 3.1.0
    • Version 3.0.1
    • Version 3.0.0
  • All options in alphabetical order:
  • Exclusions
  • Examples
  • Custom format
  • Requiring
  • Debugging
  • How Licenses are Found
  • Related information sources on the internet

This is a fork of davglass' license-checker v.25.0.1 - Since that code doesn't seem to be updated regularly, I created this fork for being able to adding new features and fixing bugs.

I changed the original exclude argument to excludeLicenses in order to prevent confusion and better align it with the excludePackages argument. Also, the argument includeLicenses has been added for listing only packages that include the licenses listed.

Please notice: Version 1.2.2 is the last version working fine on node v12. From Version 2 on, you will need at least Node v14 to run this NPM license checker. Thanks to @daniel-schulz for pointing this out!

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

It's this easy:

npm install -g license-checker-rseidelsohn

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

You should see something like this:

├─ [email protected]
│  ├─ repository: http://github.com/chriso/cli
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-glob
│  └─ licenses: UNKNOWN
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-graceful-fs
│  └─ licenses: UNKNOWN
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/inherits
│  └─ licenses: UNKNOWN
├─ [email protected]
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-lru-cache
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-lru-cache
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/minimatch
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/minimatch
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/sigmund
│  └─ licenses: UNKNOWN
└─ [email protected]
   ├─ 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:

└─ [email protected]
   ├─ repository: https://github.com/visionmedia/debug
   └─ licenses: MIT*

Add new option --limitAttributes. Example usage: node bin/license-checker-rseidelsohn --limitAttributes publisher,email will only list the publisher and email attributes for every dependency.

Fix the --direct option.

From now on, when you give the --files option, this tool outputs the path to the copied license files rather than to the originals. When the relativeLicensePath option is given, this path will either be relative to the working directory or - if also the out option is given - relative to the out path.

When using the --out option, you will not see output in the console, as the output goes into the file specified by --out. When using the --files option without --out option, you will now get console output, which was not the case before.

• --angularCli is just a synonym for --plainVertical
• --csv output in csv format.
• --csvComponentPrefix prefix column for component in csv format.
• --customPath to add a custom Format file in JSON
• --development only show development dependencies.
• --direct look for direct dependencies only
• --excludeLicenses [list] exclude modules which licenses are in the comma-separated list from the output
• --excludePackages [list] restrict output to the packages (either "package@fullversion" or "package@majorversion" or only "package") not in the semicolon-seperated list
• --excludePackagesStartingWith [list] exclude modules which names start with the comma-separated list from the output (useful for excluding modules from a specific vendor and such). Example: --excludePackagesStartingWith "webpack;@types;@babel"
• --excludePrivatePackages restrict output to not include any package marked as private
• --failOn [list] fail (exit with code 1) on the first occurrence of the licenses of the semicolon-separated list
• --files [path] copy all license files to path and rename them to module-name@version-LICENSE.txt.
• --includeLicenses [list] include only modules which licenses are in the comma-separated list from the output
• --includePackages [list] restrict output to the packages (either "package@fullversion" or "package@majorversion" or only "package") in the semicolon-seperated list
• --json output in json format.
• --limitAttributes [list] limit the attributes to be output.
• --markdown output in markdown format.
• --nopeer skip peer dependencies in output.
• --onlyAllow [list] fail (exit with codexclusionse 1) on the first occurrence of the licenses not in the semicolon-seperated list
• --onlyunknown only list packages with unknown or guessed licenses.
• --out [filepath] write the data to a specific file.
• --plainVertical output license info in plain vertical format like Angular CLI does
• --production only show production dependencies.
• --relativeLicensePath output the location of the license files as relative paths
• --relativeModulePath output the location of the module files as relative paths
• --start [filepath] path of the initial json to look for
• --summary output a summary of the license usage',
• --unknown report guessed licenses as unknown licenses.
• --version The current version
• --help The text you are reading right now :)

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.

license-checker-rseidelsohn --json > /path/to/licenses.json
license-checker-rseidelsohn --csv --out /path/to/licenses.csv
license-checker-rseidelsohn --unknown
license-checker-rseidelsohn --customPath customFormatExample.json
license-checker-rseidelsohn --excludeModules 'MIT, MIT OR X11, BSD, ISC'
license-checker-rseidelsohn --includePackages '[email protected];[email protected];[email protected]'
license-checker-rseidelsohn --excludePackages 'internal-1;internal-2'
license-checker-rseidelsohn --onlyunknown

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:

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

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

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

checker.init(
    {
        start: '/path/to/start/looking',
    },
    // eslint-disable-next-line no-unused-vars
    function (err, packages) {
        if (err) {
            //Handle error
        } else {
            //The sorted package data
            //as an Object
        }
    },
);

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

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

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

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

We walk through the node_modules directory with the read-installed-packages 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.

• ChooseALicense.com - aims at helping you in choosing an open source license for your project
• TLDRLegal.com - aims at exlaining complicated legal details of software licenses in easy to understand english