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OSS Review Toolkit Logo



Linux build status Windows build status Docker build status JitPack build status

Linux analyzer tests Windows analyzer tests Code coverage

TODOs Static Analysis LGTM REUSE status CII


The OSS Review Toolkit (ORT) aims to assist with the tasks that commonly need to be performed in the context of license compliance checks, especially for (but not limited to) Free and Open Source Software dependencies.

It does so by orchestrating a highly customizable pipeline of tools that abstract away the underlying services. These tools are implemented as libraries (for programmatic use) and exposed via a command line interface (for scripted use):

  • Analyzer - determines the dependencies of projects and their metadata, abstracting which package managers or build systems are actually being used.
  • Downloader - fetches all source code of the projects and their dependencies, abstracting which Version Control System (VCS) or other means are used to retrieve the source code.
  • Scanner - uses configured source code scanners to detect license / copyright findings, abstracting the type of scanner.
  • Advisor - retrieves security advisories for used dependencies from configured vulnerability data services.
  • Evaluator - evaluates license / copyright findings against customizable policy rules and license classifications.
  • Reporter - presents results in various formats such as visual reports, Open Source notices or Bill-Of-Materials (BOMs) to easily identify dependencies, licenses, copyrights or policy rule violations.


From binaries

Preliminary binary artifacts for ORT are currently available via JitPack. Please note that due to limitations with the JitPack build environment, the reporter is not able to create the Web App report.

From sources

Install the following basic prerequisites:

  • Git (any recent version will do).

Then clone this repository. If you intend to run tests, you need to clone with submodules by running git clone --recurse-submodules. If you have already cloned non-recursively, you can initialize submodules afterwards by running git submodule update --init --recursive.

Build using Docker

Install the following basic prerequisites:

  • Docker 18.09 or later (and ensure its daemon is running).
  • Enable BuildKit for Docker.

Change into the directory with ORT's source code and run docker build -t ort ..

Build natively

Install these additional prerequisites:

  • Java Development Kit (JDK) version 11 or later; also remember to set the JAVA_HOME environment variable accordingly.

Change into the directory with ORT's source code and run ./gradlew installDist (on the first run this will bootstrap Gradle and download all required dependencies).

Basic usage

ORT can now be run using

./cli/build/install/ort/bin/ort --help

Note that if you make any changes to ORT's source code, you would have to regenerate the distribution using the steps above.

To avoid that, you can also build and run ORT in one go (if you have the prerequisites from the Build natively section installed):

./gradlew cli:run --args="--help"

Note that in this case the working directory used by ORT is that of the cli project, not the directory gradlew is located in (see

Running the tools

Like for building ORT from sources you have the option to run ORT from a Docker image (which comes with all runtime dependencies) or to run ORT natively (in which case some additional requirements need to be fulfilled).

Run using Docker

After you have built the image as described above, simply run docker run <DOCKER_ARGS> ort <ORT_ARGS>. You typically use <DOCKER_ARGS> to mount the project directory to analyze into the container for ORT to access it, like:

docker run -v /workspace:/project ort --info analyze -f JSON -i /project -o /project/ort/analyzer

You can find further hints for using ORT with Docker in the documentation.

Run natively

First of all, make sure that the locale of your system is set to en_US.UTF-8 as using other locales might lead to issues with parsing the output of some external tools.

Then install any missing external command line tools as listed by

./cli/build/install/ort/bin/ort requirements


./gradlew cli:run --args="requirements"

Then run ORT like

./cli/build/install/ort/bin/ort --info analyze -f JSON -i /project -o /project/ort/analyzer


./gradlew cli:run --args="--info analyze -f JSON -i /project -o /project/ort/analyzer"

Running on CI

A basic ORT pipeline (using the analyzer, scanner and reporter) can easily be run on Jenkins CI by using the Jenkinsfile in a (declarative) pipeline job. Please see the Jenkinsfile itself for documentation of the required Jenkins plugins. The job accepts various parameters that are translated to ORT command line arguments. Additionally, one can trigger a downstream job which e.g. further processes scan results. Note that it is the downstream job's responsibility to copy any artifacts it needs from the upstream job.

A demo instance of a Jenkins pipeline for ORT will soon be

Fosshost Logo

Getting started

Please see Getting Started for an introduction to the individual tools.


Environment variables

ORT supports several environment variables that influence its behavior:

Name Default value Purpose
ORT_DATA_DIR ~/.ort All data, like caches, archives, storages (read & write)
ORT_CONFIG_DIR $ORT_DATA_DIR/config Configuration files, see below (read only)
ORT_HTTP_USERNAME Empty (n/a) Generic username to use for HTTP(S) downloads
ORT_HTTP_PASSWORD Empty (n/a) Generic password to use for HTTP(S) downloads
http_proxy Empty (n/a) Proxy to use for HTTP downloads
https_proxy Empty (n/a) Proxy to use for HTTPS downloads

Configuration files

ORT looks for its configuration files in the directory pointed to by the ORT_CONFIG_DIR environment variable. If this variable is not set, it defaults to the config directory below the directory pointed to by the ORT_DATA_DIR environment variable, which in turn defaults to the .ort directory below the current user's home directory.

The following provides an overview of the various configuration files that can be used to customize ORT behavior:

ORT configuration file

The main configuration file for the operation of ORT. This configuration is maintained by an administrator who manages the ORT instance. In contrast to the configuration files in the following, this file rarely changes once ORT is operational.

Format Scope Default location Default value
HOCON Global $ORT_CONFIG_DIR/ort.conf Empty

The reference configuration file gives a good impression about the content of the main ORT configuration file. It consists of sections related to different sub components of ORT. The meaning of these sections and the properties they can contain is described together with the corresponding sub components.

While the file is rather static, there are means to override configuration options for a specific run of ORT or to customize the configuration to a specific environment. The following options are supported, in order of precedence:

  • Properties can be defined via environment variables by using the full property path as the variable name. For instance, one can override the Postgres schema by setting ort.scanner.storages.postgresStorage.schema=test_schema. The variable's name is case sensitive. Some programs like Bash do not support dots in variable names. For this case, the dots can be replaced by double underscores, i.e., the above example is turned into ort__scanner__storages__postgresStorage__schema=test_schema.

  • In addition to that, one can override the values of properties on the command line using the -P option. The option expects a key-value pair. Again, the key must define the full path to the property to be overridden, e.g. -P ort.scanner.storages.postgresStorage.schema=test_schema. The -P option can be repeated on the command line to override multiple properties.

  • Properties in the configuration file can reference environment variables using the syntax ${VAR}. This is especially useful to reference dynamic or sensitive data. As an example, the credentials for the Postgres database used as scan results storage could be defined in the POSTGRES_USERNAME and POSTGRES_PASSWORD environment variables. The configuration file can then reference these values as follows:

    postgres {
      url = "jdbc:postgresql://your-postgresql-server:5444/your-database"
      username = ${POSTGRES_USERNAME}
      password = ${POSTGRES_PASSWORD}

Copyright garbage file

A list of copyright statements that are considered garbage, for example statements that were incorrectly classified as copyrights by the scanner.

Format Scope Default location Default value
YAML / JSON Global $ORT_CONFIG_DIR/copyright-garbage.yml Empty (n/a)

Curations file

A file to correct invalid or missing package metadata, and to set the concluded license for packages.

Format Scope Default location Default value
YAML / JSON Global $ORT_CONFIG_DIR/curations.yml Empty (n/a)

Custom license texts dir

A directory that contains license texts which are not provided by ORT.

Format Scope Default location Default value
Text Global $ORT_CONFIG_DIR/custom-license-texts/ Empty (n/a)

How to fix text provider script

A Kotlin script that enables the injection of how-to-fix texts in markdown format for ORT issues into the reports.

Format Scope Default location Default value
Kotlin script Global $ORT_CONFIG_DIR/how-to-fix-text-provider.kts Empty (n/a)

License classifications file

A file that contains user-defined categorization of licenses.

Format Scope Default location Default value
YAML / JSON Global $ORT_CONFIG_DIR/license-classifications.yml Empty (n/a)

Resolution file

Configurations to resolve any issues or rule violations by providing a mandatory reason, and an optional comment to justify the resolution on a global scale.

Format Scope Default location Default value
YAML / JSON Global $ORT_CONFIG_DIR/resolutions.yml Empty (n/a)

Repository configuration file

A configuration file, usually stored in the project's repository, for license finding curations, exclusions, and issues or rule violations resolutions in the context of the repository.

Format Scope Default location Default value
YAML / JSON Repository (project) [analyzer-input-dir]/.ort.yml Empty (n/a)

Package configuration file / directory

A single file or a directory with multiple files containing configurations to set provenance-specific path excludes and license finding curations for dependency packages to address issues found within a scan result. helper-cli's package-config create command can be used to populate a directory with template package configuration files.

Format Scope Default location Default value
YAML / JSON Package (dependency) $ORT_CONFIG_DIR/package-configurations/ Empty (n/a)

Policy rules file

The file containing any policy rule implementations to be used with the evaluator.

Format Scope Default location Default value
Kotlin script (DSL) Evaluator $ORT_CONFIG_DIR/rules.kts Empty (n/a)

Details on the tools


The analyzer is a Software Composition Analysis (SCA) tool that determines the dependencies of software projects inside the specified input directory (-i). It does so by querying the detected package managers; no modifications to your existing project source code, like applying build system plugins, are necessary for that to work. The tree of transitive dependencies per project is written out as part of an OrtResult in YAML (or JSON, see -f) format to a file named analyzer-result.yml in the specified output directory (-o). The output file exactly documents the status quo of all package-related metadata. It can be further processed or manually edited before passing it to one of the other tools.

Currently, the following package managers (grouped by the programming language they are most commonly used with) are supported:

If another package manager that is not part of the list above is used (or no package manager at all), the generic fallback to SPDX documents can be leveraged to describe projects or packages.



Taking an ORT result file with an analyzer result as the input (-i), the downloader retrieves the source code of all contained packages to the specified output directory (-o). The downloader takes care of things like normalizing URLs and using the appropriate VCS tool to checkout source code from version control.

Currently, the following Version Control Systems (VCS) are supported:



This tool wraps underlying license / copyright scanners with a common API so all supported scanners can be used in the same way to easily run them and compare their results. If passed an ORT result file with an analyzer result (-i), the scanner will automatically download the sources of the dependencies via the downloader and scan them afterwards.

We recommend to use ORT with one of the following scanners as their integration has been thoroughly tested (in alphabetical order):

Additionally, the following reference implementations exist (in alphabetical order):

For a comparison of some of these, see this Bachelor Thesis.

Storage Backends

In order to not download or scan any previously scanned sources again, or to reuse scan results generated via other services, the scanner can be configured to use so-called storage backends. Before processing a package, it checks whether compatible scan results are already available in one of the storages declared; if this is the case, they are fetched and reused. Otherwise, the package's source code is downloaded and scanned. Afterwards, the new scan results can be put into a storage for later reuse.

It is possible to configure multiple storages to read scan results from or to write scan results to. For reading, the declaration order in the configuration is important, as the scanner queries the storages in this order and uses the first matching result. This allows a fine-grained control over the sources, from which existing scan results are loaded. For instance, you can specify that the scanner checks first whether results for a specific package are available in a local storage on the file system. If this is not the case, it can look up the package in a Postgres database. If this does not yield any results either, a service like ClearlyDefined can be queried. Only if all of these steps fail, the scanner has to actually process the package.

When storing a newly generated scan result the scanner invokes all the storages declared as writers. The storage operation is considered successful if all writer storages could successfully persist the scan result.

The configuration of storage backends is located in the ORT configuration file. (For the general structure of this file and the set of options available refer to the reference configuration.) The file has a section named storages that lists all the storage backends and assigns them a name. Each storage backend is of a specific type and needs to be configured with type-specific properties. The different types of storage backends supported by ORT are described below.

After the declaration of the storage backends, the configuration file has to specify which ones of them the scanner should use for looking up existing scan results or to store new results. This is done in two list properties named storageReaders and storageWriters. The lists reference the names of the storage backends declared in the storages section. The scanner invokes the storage backends in the order they appear in the lists; so for readers, this defines a priority for look-up operations. Each storage backend can act as a reader; however, some types do not support updates and thus cannot serve as writers. If a storage backend is referenced both as reader and writer, the scanner creates only a single instance of this storage class.

The following subsections describe the different storage backend implementations supported by ORT. Note that the name of a storage entry (like fileBasedStorage) can be freely chosen. That name is then used to refer to the storage from the storageReaders and storageWriters sections.

Local File Storage

By default, the scanner stores scan results on the local file system in the current user's home directory (i.e. ~/.ort/scanner/scan-results) for later reuse. Settings like the storage directory and the compression flag can be customized in the ORT configuration file (-c) with a respective storage configuration:

ort {
  scanner {
    storages {
      fileBasedStorage {
        backend {
          localFileStorage {
            directory = "/tmp/ort/scan-results"
            compression = false

    storageReaders: [

    storageWriters: [

HTTP Storage

Any HTTP file server can be used to store scan results. Custom headers can be configured to provide authentication credentials. For example, to use Artifactory to store scan results, use the following configuration:

ort {
  scanner {
    storages {
      artifactoryStorage {
        backend {
          httpFileStorage {
            url = ""
            headers {
              X-JFrog-Art-Api = "api-token"

    storageReaders: [

    storageWriters: [

PostgreSQL Storage

To use PostgreSQL for storing scan results you need at least version 9.4, create a database with the client_encoding set to UTF8, and a configuration like the following:

ort {
  scanner {
    storages {
      postgresStorage {
        url = "jdbc:postgresql://"
        schema = "public"
        username = "username"
        password = "password"
        sslmode = "verify-full"

    storageReaders: [

    storageWriters: [

The database needs to exist. If the schema is set to something else than the default of public, it needs to exist and be accessible by the configured username.

The scanner will itself create a table called scan_results and store the data in a jsonb column.

If you do not want to use SSL set the sslmode to disable, other possible values are explained in the documentation. For other supported configuration options see ScanStorageConfiguration.kt.

ClearlyDefined Storage

ClearlyDefined is a service offering curated metadata for Open Source components. This includes scan results that can be used by ORT's scanner tool (if they have been generated by a compatible scanner version with a suitable configuration). This storage backend queries the ClearlyDefined service for scan results of the packages to be processed. It is read-only; so it will not upload any new scan results to ClearlyDefined. In the configuration the URL of the ClearlyDefined service needs to be set:

ort {
  scanner {
    storages {
      clearlyDefined {
        serverUrl = ""

    storageReaders: [



The advisor retrieves security advisories from configured services. It requires the analyzer result as an input. For all the packages identified by the analyzer, it queries the services configured for known security vulnerabilities. The vulnerabilities returned by these services are then stored in the output result file together with additional information like the source of the data and a severity (if available).

Multiple providers for security advisories are available. The providers require specific configuration in the ORT configuration file, which needs to be placed in the advisor section. When executing the advisor the providers to enable are selected with the --advisors option (or its short alias -a); here a comma-separated list with provider IDs is expected. The following sections describe the providers supported by the advisor:


A security data provider that queries Nexus IQ Server. In the configuration, the URL where Nexus IQ Server is running and the credentials to authenticate need to be provided:

ort {
  advisor {
    nexusIq {
      serverUrl = ""
      username = myUser
      password = myPassword

To enable this provider, pass -a NexusIQ on the command line.

OSS Index

This vulnerability provider does not require any further configuration as it uses the public service at

To enable this provider, pass -a OssIndex on the command line.


This provider obtains information about security vulnerabilities from a VulnerableCode instance. The configuration is limited to the server URL, as authentication is not required:

ort {
  advisor {
    vulnerableCode {
      serverUrl = "http://localhost:8000"

To enable this provider, pass -a VulnerableCode on the command line.



The evaluator is used to perform custom license policy checks on scan results. The rules to check against are implemented as scripts (currently Kotlin scripts, with a dedicated DSL, but support for other scripting can be added as well. See rules.kts for an example file.



The reporter generates a wide variety of documents in different formats from ORT result files. Currently, the following formats are supported (reporter names are case-insensitive):

  • AsciiDoc Template (-f AsciiDocTemplate)
  • CycloneDX BOM (-f CycloneDx)
  • Excel sheet (-f Excel)
  • GitLabLicenseModel (-f GitLabLicenseModel)
    • A nice tutorial video has been published by GitLab engineer @mokhan.
  • NOTICE file in two variants
    • List license texts and copyrights by package (-f NoticeTemplate)
    • Summarize all license texts and copyrights (-f NoticeTemplate -O
    • Customizable with Apache Freemarker templates
  • SPDX Document, version 2.2 (-f SpdxDocument)
  • Static HTML (-f StaticHtml)
  • Web App (-f WebApp)

System requirements

ORT is being continuously used on Linux, Windows and macOS by the core development team, so these operating systems are considered to be well supported.

To run the ORT binaries (also see Installation from binaries) at least Java 11 is required. Memory and CPU requirements vary depending on the size and type of project(s) to analyze / scan, but the general recommendation is to configure Java with 8 GiB of memory (-Xmx=8g) and to use a CPU with at least 4 cores.

If ORT requires external tools in order to analyze a project, these tools are listed by the ort requirements command. If a package manager is not list listed there, support for it is integrated directly into ORT and does not require any external tools to be installed.


ORT is written in Kotlin and uses Gradle as the build system, with Kotlin script instead of Groovy as the DSL.

When developing on the command line, use the committed Gradle wrapper to bootstrap Gradle in the configured version and execute any given tasks. The most important tasks for this project are:

Task Purpose
assemble Build the JAR artifacts for all projects
detekt Run static code analysis on all projects
test Run unit tests for all projects
funTest Run functional tests for all projects
installDist Build all projects and install the start scripts for distribution

All contributions need to pass the detekt, test and funTest checks before they can be merged.

For IDE development we recommend the IntelliJ IDEA Community Edition which can directly import the Gradle build files. After cloning the project's source code recursively, simply run IDEA and use the following steps to import the project.

  1. From the wizard dialog: Select Import Project.

    From a running IDEA instance: Select File -> New -> Project from Existing Sources...

  2. Browse to ORT's source code directory and select either the build.gradle.kts or the settings.gradle.kts file.

  3. In the Import Project from Gradle dialog select Use auto-import and leave all other settings at their defaults.


To set up a basic run configuration for debugging, navigate to OrtMain.kt in the cli module and look for the fun main(args: Array<String>) function. In the gutter next to it, a green "Play" icon should be displayed. Click on it and select Run 'OrtMainKt' to run the entry point, which implicitly creates a run configuration. Double-check that running ORT without any arguments will simply show the command line help in IDEA's Run tool window. Finally, edit the created run configuration to your needs, e.g. by adding an argument and options to run a specific ORT sub-command.


For running tests and individual test cases from the IDE, the kotest plugin needs to be installed. Afterwards tests can be run via the green "Play" icon from the gutter as described above.


Copyright (C) 2017-2021 HERE Europe B.V.
Copyright (C) 2019-2020 Bosch Software Innovations GmbH
Copyright (C) 2020-2021 Bosch.IO GmbH

See the LICENSE file in the root of this project for license details.

OSS Review Toolkit (ORT) is a Linux Foundation project and part of ACT.