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flict / FOSS License Compatibility Tool


FOSS License Compatibility Tool (flict) is a Free and Open Source Software tool to verify license compatibility for a package and its dependencies. You can use the tool to automate license compatibility verification in your compliance work flow.

flict can:

  • verify licenses compatibilty for license expression and a packages and its dependencies

  • suggest candidate outbound licenses

  • simplify license expressions

  • display, in misc format, compatibilies between licenses

  • check outbound licenses against a policy (policy as supplied by the user)

flict supports:

  • 71 licenses (flict -of text list)

  • 925 licenses in experimental mode using scancode classification (flict -es -of text list)

  • 'or-later' relicensing (e.g GPL-2.0-or-later -> GPL-2.0-only or GPL-3.0-only)

  • explicit relicensing (LGPL -> GPL)

  • common non SPDX ways to write licenses (e.g GPLv2 -> GPL-2.0-only)

  • grouping of common licenses in to well known license classification

  • policy framework where you can specify which licenses you want to: allow, avoid or deny


Check out our EXAMPLES

Extensible and tweakable

flict does not come with any knowledge about certain policies, licenses and their compatibilities. These things are specified outside the tool, using JSON and CSV files. By default flict has files defining licenses and compatibilities which probably gets most of our users going. Having licenses and compatibilities (and even more stuff) defined outside the tool makes it easy to extend the tool with new licenses etc without modifying the code.

Read more in SETTINGS

Supported licenses

License matrix

To check compatibility between two licenses flict is using OSADL's matrix.

Scancode's db

Flict can also (experimentally) use Scancode's database.


Look at our INSTALLATION page.

Docker image

Flict is included in the docker image Compliance Tools which is easily managed by Compliance Tool Collection

Exit code and reports

flict outputs a report as well as an exit code.

Exit code

0 - success

5 - missing arguments

10 - invalid project file

10 - invalid license expression


A report of the component's compatibility with suggested outbound licenses is created. By default a short text report is created, but flict can provide a report in a couple of formats.

Report formats


This is currently rewritten and not available.


Using this format you can create txt, html, pdf and what format pandoc can create from markdown.

User specific configuration

You can create a user specific configuration for the tool that defines a few default parameters to your choices. Either create a json file at ~/.flict.cfg or at a path defined by environment variable FLICT_USERCONFIG.

key sets CLI option
group-file -gf --group-file
matrix-file -mf --matrix-file
output-format -of --output-format
relicense-file -rf --relicense-file
scancode-file -sf --scancode-file
translations-file -tf --translations-file

Example user configuration

    "matrix-file": "/my/very/own/osadl-matrix.csv",
    "output-format": "text",
    "scancode-file": "/my/secret/stash/scancode-licenses.json"

Policy report

To the above report you can apply your own policy (see SETTINGS). Applying this will create a policy report with your policy applied to the suggested outbound license from the usual report and with some complementary information.

Reporting bugs

File a ticket at

Contribute to the project


License of flict

flict is released under GPLv3 (