Find licenses for your project's dependencies.
Ruby HTML Python Shell Erlang Batchfile
Latest commit c377463 Feb 7, 2017 @Manifaust Manifaust remove travis configuration
[finish #138444751]

License Finder

Code Climate

Build status

  • Ruby 2.1.5 Ruby 2.1.5 build status
  • Ruby 2.2.0 Ruby 2.2.0 build status
  • Ruby 2.3.0 Ruby 2.3.0 build status
  • Ruby 2.4.0 Ruby 2.4.0 build status
  • JRuby JRuby build status

LicenseFinder works with your package managers to find dependencies, detect the licenses of the packages in them, compare those licenses against a user-defined whitelist, and give you an actionable exception report.

Supported project types

  • Ruby Gems (via bundler)
  • Python Eggs (via pip)
  • Node.js (via npm)
  • Bower
  • Nuget (without license discovery)
  • Godep
  • Go workspace (via a .envrc file)
  • Go submodules
  • Java (via maven)
  • Java (via gradle)

Experimental project types


License Finder requires Ruby 1.9.3 or greater to run. If you have an older version of Ruby installed, you can update via Homebrew:

$ ruby -e "$(curl -fsSL"


$ brew install ruby

The easiest way to use license_finder is to install it as a command line tool, like brew, awk, gem or bundler:

$ gem install license_finder

Though it's less preferable, if you are using bundler in a Ruby project, you can add license_finder to your Gemfile:

gem 'license_finder', :group => :development

This approach helps you remember to install license_finder, but can pull in unwanted dependencies, including bundler. To mitigate this problem, see Excluding Dependencies.


Make sure your dependencies are installed (with your package manager's install command: bundle install, npm install, etc.)

The first time you run license_finder it will list all your project's packages.

$ license_finder

Or, if you installed with bundler:

$ bundle exec license_finder

The output will report that none of your packages have been approved. Over time you will tell license_finder which packages are approved, so when you run this command in the future, it will report current action items; i.e., packages that are new or have never been approved.

If you don't wish to see progressive output "dots", use the --quiet option.

If you'd like to see debugging output, use the --debug option. license_finder will then output info about packages, their dependencies, and where and how each license was discovered. This can be useful when you need to track down an unexpected package or license.

Run license_finder help to see other available commands, and license_finder help [COMMAND] for detailed help on a specific command.


license_finder will find and include packages for all supported languages, as long as that language has a package definition in the project directory:

  • Gemfile (for bundler)
  • requirements.txt (for pip)
  • package.json (for npm)
  • pom.xml (for maven)
  • build.gradle (for gradle)
  • settings.gradle that specifies rootProject.buildFileName (for gradle)
  • bower.json (for bower)
  • Podfile (for CocoaPods)
  • rebar.config (for rebar)
  • packages/ directory (for Nuget)

Continuous Integration

license_finder will return a non-zero exit status if there are unapproved dependencies. This can be useful for inclusion in a CI environment to alert you if someone adds an unapproved dependency to the project.

Approving Dependencies

license_finder will inform you whenever you have an unapproved dependency. If your business decides this is an acceptable risk, the easiest way to approve the dependency is by running license_finder approval add.

For example, let's assume you've added the awesome_gpl_gem to your Gemfile, which license_finder reports is unapproved:

$ license_finder
Dependencies that need approval:
awesome_gpl_gem, 1.0.0, GPL

Your business tells you that in this case, it's acceptable to use this gem. You now run:

$ license_finder approval add awesome_gpl_gem

If you rerun license_finder, you should no longer see awesome_gpl_gem in the output.

To record who approved the dependency and why:

$ license_finder approval add awesome_gpl_gem --who CTO --why "Go ahead"


Approving packages one-by-one can be tedious. Usually your business has blanket policies about which packages are approved. To tell license_finder that any package with the MIT license should be approved, run:

$ license_finder whitelist add MIT

Any current or future packages with the MIT license will be excluded from the output of license_finder.

You can also record --who and --why when changing the whitelist, or making any other decision about your project.

Output and Artifacts

Decisions file

Any decisions you make about approvals will be recorded in a YAML file named doc/dependency_decisions.yml.

This file must be committed to version control. Rarely, you will have to manually resolve conflicts in it. In this situation, keep in mind that each decision has an associated timestamp, and the decisions are processed top-to-bottom, with later decisions overwriting or appending to earlier decisions.

Output from action_items

You could expect license_finder, which is an alias for license_finder action_items to output something like the following on a Rails project where MIT had been whitelisted:

Dependencies that need approval:

highline, 1.6.14, ruby
json, 1.7.5, ruby
mime-types, 1.19, ruby
rails, 3.2.8, unknown
rdoc, 3.12, unknown
rubyzip, 0.9.9, ruby
xml-simple, 1.1.1, unknown

You can customize the format of the output in the same way that you customize output from report.

Output from report

The license_finder report command will output human-readable reports that you could send to your non-technical business partners, lawyers, etc. You can choose the format of the report (text, csv, html or markdown); see license_finder --help report for details. The output is sent to STDOUT, so you can save the reports wherever you want them. You can commit them to version control if you like.

The HTML report generated by license_finder report --format html summarizes all of your project's dependencies and includes information about which need to be approved. The project name at the top of the report can be set with license_finder project_name add.

See for advice about adding and customizing reports.

Manual Intervention

Setting Licenses

When license_finder reports that a dependency's license is 'unknown', you should manually research what the actual license is. When you have established the real license, you can record it with:

$ license_finder licenses add my_unknown_dependency MIT

This command would assign the MIT license to the dependency my_unknown_dependency.

Adding Hidden Dependencies

license_finder can track dependencies that your package managers don't know about (JS libraries that don't appear in your Gemfile/requirements.txt/package.json, etc.)

$ license_finder dependencies add my_js_dep MIT 0.1.2

Run license_finder dependencies help for additional documentation about managing these dependencies.

license_finder cannot automatically detect when one of these dependencies has been removed from your project, so you can use:

$ license_finder dependencies remove my_js_dep

Excluding Dependencies

Sometimes a project will have development or test dependencies which you don't want to track. You can exclude theses dependencies by running license_finder ignored_groups. (Currently this only works for packages managed by Bundler, NPM, and Nuget.)

On rare occasions a package manager will report an individual dependency that you want to exclude from all reports, even though it is approved. You can exclude an individual dependency by running license_finder ignored_dependencies. Think carefully before adding dependencies to this list. A likely item to exclude is bundler, since it is a common dependency whose version changes from machine to machine. Adding it to the ignored_dependencies would prevent it (and its oscillating versions) from appearing in reports.

Blacklisting Licenses

Some projects will have a list of licenses that cannot be used. You can add these licenses to the blacklist license_finder blacklist add. Any dependency that has exclusively blacklisted licenses will always appear in the action items, even if someone attempts to manually approve or whitelist it. However, if a dependency has even one license outside of the blacklist, it can still be manually approved or whitelisted.


Be default, license_finder expects the decisions file to be stored at doc/dependency_decisions.yml. All commands can be passed --decisions_file to override this location.

Of Package Managers

If you have a gradle project, you can invoke gradle with a custom script by passing (for example) --gradle_command gradlew to license_finder or license_finder report.

Similarly you can invoke a custom rebar script with --rebar_command rebar2. If you store rebar dependencies in a custom directory (by setting deps_dir in rebar.config), set --rebar_deps_dir.

Saving Configuration

It may be difficult to remember to pass command line options to every command. In some of these cases you can store default values in a YAML formatted config file. license_finder looks for this file in config/license_finder.yml.

As an example, the file might look like this:

decisions_file: './some_path/decisions.yml'
gradle_command: './gradlew'
rebar_command: './rebarw'
rebar_deps_dir: './rebar_deps'

Gradle Projects

license_finder supports both Gradle 1.x and Gradle 2.x. You need to have installed the license-gradle-plugin in your project:

By default, license_finder will report on Gradle's "runtime" dependencies. If you want to generate a report for some other dependency configuration (e.g. Android projects will sometimes specify their meaningful dependencies in the "compile" group), you can specify it in your project's build.gradle:

// Must come *after* the 'apply plugin: license' line

downloadLicenses {
  dependencyConfiguration "compile"

Maven Projects

license_finder supports Maven.


license_finder requires ruby >= 1.9, or jruby.


To upgrade from license_finder version 1.2 to 2.0, see license_finder_upgrade. To upgrade to 2.0 from a version lower than 1.2, first upgrade to 1.2, and run license_finder at least once. This will ensure that the license_finder database is in a state which license_finder_upgrade understands.

A Plea to Package Authors and Maintainers

Please add a license to your package specs! Most packaging systems allow for the specification of one or more licenses.

For example, Ruby Gems can specify a license by name: do |s| = "my_great_gem"
  s.license = "MIT"

And save a LICENSE file which contains your license text in your repo.





LicenseFinder is released under the MIT License.