There's a lot of open issues
A long-lived project that still receives updates
LicenseFinder works with your package managers to find dependencies, detect the licenses of the packages in them, compare those licenses against a user-defined list of permitted licenses, and give you an actionable exception report.


~> 3.39.2
~> 2.5.0
~> 1.10
> 0.7, ~> 2.1.0
~> 3
~> 1.3.0
~> 0.1.0
~> 0.4.2
= 3.5.2
~> 0.14.1
~> 3.0.0
~> 13.1.0
~> 1.60.2
~> 3.14


~> 3.2
>= 1, < 3
>= 1.3, < 2.1
= 1.1.0
~> 1.2
~> 1.1.9
 Project Readme

License Finder

Code Climate

Build status

  • Ruby 2.7.8 Ruby 2.7.8 build status
  • Ruby 3.1.4 Ruby 3.1.4 build status
  • Ruby 3.2.3 Ruby 3.2.3 build status
  • Ruby 3.3.0 Ruby 3.3.0 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 list of permitted licenses, and give you an actionable exception report.

Supported project types

Project Type Package Manager Tested on Version
Ruby Gems bundler 2.3.7
Python 2.7 Eggs pip2 19.0.2
Python 3.5 Eggs pip3 20.0.2
Node.js npm 6.4.1
Bower bower 1.8.4
Nuget (without license discovery) nuget
Godep Godep 80
Go workspace Go lang 1.11.5
Go modules Go lang 1.14.3
Java maven 3.6.0
Java gradle 5.6.4

Experimental project types

  • Erlang (via rebar and Erlang.mk)
  • Objective-C, Swift (via Carthage, CocoaPods [0.39 and below. See CocoaPods Specs Repo Sharding]) and Swift Package Manager(SPM)
  • Elixir (via mix)
  • Golang (via gvt, glide,dep, trash and govendor)
  • JavaScript (via yarn)
  • C++/C (via conan)
  • Scala (via sbt)
  • Rust (via cargo)
  • PHP (via composer)
  • Python (via Conda, pipenv)
  • Flutter (via flutter pub)


License Finder may be run as a pre-commit hook by adding the following to your .pre-commit-config.yaml:

  - repo: https://github.com/pivotal/LicenseFinder
    rev: v7.1.0 # You probably want the latest tag.
      - id: license-finder

Running License Finder directly requires Ruby 2.6.0 or greater. If you have an older version of Ruby installed, you can update via Homebrew:

$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"


$ brew install ruby

The easiest way to use license_finder directly 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.

If you do not want to manually run an individual package manager's prepare command (ex: bundle install, npm install, etc) to ensure your project is fully prepared to be scanned, use the --prepare or -p option which will run each active package manager's prepare command for you. If you would like to continue running license_finder even if there is an issue with a prepare step, use the --prepare-no-fail option which prepares but carries on despite any potential failures.

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


If you have docker installed, try using the included dlf script (potentially symlinked to be in your path via ln -s LicenseFinder/dlf /usr/local/bin or whatever method you prefer). This will run any commands passed to it inside a pre-provisioned Docker container to maintain consistent versions of all the package managers. For example,

$ dlf npm --version

$ dlf license_finder --help

Dependencies that need approval:
license_finder, 3.0.3, MIT

$ dlf "bundle install && license_finder"

You can better understand the way this script works by looking at its source, but for reference it will mount your current directory at the path /scan and run any commands passed to it from that directory. If your command has &&, ensure you quote the command. If it does not, ensure the command is not quoted.

Note that the docker image will run the gem which is installed within it. So the docker image tagged 7.0.0 will run License Finder Version 7.0.0

See the contributing guide for information on development.


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)
  • Pipfile.lock (for pipenv)
  • package.json (for npm)
  • pom.xml (for maven)
  • build.gradle or build.gradle.kts (for gradle)
  • settings.gradle that specifies rootProject.buildFileName (for gradle)
  • bower.json (for bower)
  • Podfile (for pod) (set ACKNOWLEDGEMENTS_PATH variable if you want to target a particular Pods-acknowledgements-<TARGET>.plist. Can be useful in multi-target pods projects.)
  • Cartfile (for carthage)
  • workspace-state.json under build directory (provided as enviroment variable SPM_DERIVED_DATA for Xcode, or default .build for non-Xcode projects), (for spm)
  • rebar.config (for rebar)
  • Erlang.mk or erlang.mk file (for Erlang.mk)
  • mix.exs (for mix)
  • packages/ directory (for nuget)
  • *.csproj (for dotnet)
  • vendor/manifest or */vendor/manifest file (for gvt)
  • glide.lock file (for glide)
  • vendor/vendor.json file (for govendor)
  • Gopkg.lock file (for dep)
  • Godeps/Godeps.json (for godep)
  • *.envrc file (for go)
  • go.mod file (for go mod)
  • vendor.conf file (for trash)
  • yarn.lock file (for yarn)
  • conanfile.txt file (for conan)
  • build.sbt file (for sbt)
  • Cargo.lock file (for cargo)
  • composer.lock file (for composer)
  • environment.yml file (for conda)
  • pubspec.yaml & .pub cache locaton through ENV variable (for flutter)

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 approvals 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 approvals add awesome_gpl_gem

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

To approve specific version

$ license_finder approvals add awesome_gpl_gem --version=1.0.0

To record who approved the dependency and why:

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

Permitting Licenses

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 permitted_licenses 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 permitted licenses, 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 permitted:

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 project_roots

The license_finder project_roots command will output the current working directory as a string in an array.

Using the --recursive option means the array will include subdirectories that contain a known package manager. With the exception that Gradle and Maven subprojects will not be included.

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.


When using the yarn package manager, when a node_module's package.json doesn't explicitly declare a license, yarn indicates that it has inferred the license based on some keywords in other files by appending an asterisk to the license name. If you see a * at the end of the license name, this is intended.

See CONTRIBUTING.md 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 all versions of the dependency my_unknown_dependency. If you prefer, you could instead assign the license to only a specific version of the dependency:

$ license_finder licenses add my_unknown_dependency MIT --version=1.0.0

Please note that adding a license to a specific version of a dependency will cause any licenses previously added to all versions of that dependency to be forgotten. Similarly, adding a license to all versions of a dependency will override any licenses previously added to specific versions of that dependency.

There are several ways in which you can remove licenses that were previously added through the licenses add command:

# Removes all licenses from any version of the dependency
$ license_finder licenses remove my_unknown_dependency

# Removes just the MIT license from any version of the dependency
$ license_finder licenses remove my_unknown_dependency MIT

# Removes all licenses from only version 1.0.0 of the dependency
# This has no effect if you had last added a license to all versions of the dependency
$ license_finder licenses remove my_unknown_dependency --version=1.0.0

# Removes just the MIT license from only version 1.0.0 of the dependency
# This has no effect if you had last added a license to all versions of the dependency
$ license_finder licenses remove my_unknown_dependency MIT --version=1.0.0

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, Yarn, Maven, Pip2, Pip3, 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.

Restricting Licenses

Some projects will have a list of licenses that cannot be used. You can restrict these licenses with license_finder restricted_licenses add. Any dependency that has exclusively restricted licenses will always appear in the action items, even if someone attempts to manually approve or permit it. However, if a dependency has even one license that is not restricted, it can still be manually approved or permitted.

Decision inheritance

Add or remove decision files you want to inherit from - see license_finder inherited_decisions help for more information.

This allows you to have a centralized decision file for approved/restricted licenses. If you have multiple projects it's way easier to have one single place where you approved or restricted licenses defined.

Add one or more decision files to the inherited decisions

license_finder inherited_decisions add DECISION_FILE

Remove one or more decision files from the inherited decisions

license_finder inherited_decisions remove DECISION_FILE

List all the inherited decision files

license_finder inherited_decisions list


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.

Package Manager Configuration

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 rebar. If you store rebar dependencies in a custom directory (by setting deps_dir in rebar.config), set --rebar_deps_dir.

You can also invoke a custom Mix script remix with --mix_command remix and set --mix_deps_dir to fetch Mix dependencies from a custom directory.

Narrow down Package Manager

By default, license_finder will check for all supported package managers, but you can narrow it down to use only those you pass to --enabled-package-managers. For example,

$ license_finder --enabled-package-managers bundler npm

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'
mix_command: './mixw'
mix_deps_dir: './mix_deps'
  - bundler
  - gradle
  - rebar
  - mix

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: https://github.com/hierynomus/license-gradle-plugin

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* applying the appropriate plugin from [https://github.com/hierynomus/license-gradle-plugin](https://github.com/hierynomus/license-gradle-plugin)

downloadLicenses {
  dependencyConfiguration "compile"

Conan Projects

license_finder supports Conan. You need to have the following lines in your conanfile.txt for license_finder to retrieve dependencies' licenses. Ensure that conan install does not generate an error.

., license* -> ./licenses @ folder=True, ignore_case=True

SBT Projects

license_finder supports SBT. You need to have installed the sbt-license-report in your project: https://github.com/sbt/sbt-license-report

By default, license_finder will report on SBT's "compile" and "test" dependencies. If you want to generate a report for some other dependency configuration, you can specify it in your projects's build.sbt

licenseConfigurations := Set("compile", "provided")


license_finder requires ruby >= 2.6.0.


To upgrade to license_finder version >= 6.0, you have to replace the terminology whitelist with permit and blacklist with restrict in your dependency_decisions.yml. See Changelog for more details.

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:

Gem::Specification.new do |s|
  s.name = "my_great_gem"
  s.license = "MIT"

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

Known issues with specific package managers

  • Bundler

    • When using --project-path, Bundler cannot find the Gemfile.
  • Yarn

    • A module that is incompatible with the platform on which license_finder is run will always be reported to have a license type of "unknown". (#456)





LicenseFinder is released under the MIT License. http://www.opensource.org/licenses/mit-license