sbt / sbt-proguard

Proguard sbt plugin

Version Matrix


sbt plugin for running ProGuard. This plugin requires sbt 0.13 or 1.0.

Build Status

Add plugin

Add plugin to project/plugins.sbt. For example:

addSbtPlugin("com.lightbend.sbt" % "sbt-proguard" % "{version}")

See released versions.

Note: earlier versions of sbt-proguard used the "com.typesafe.sbt" organization.


A simple build.sbt with settings to configure sbt-proguard:


proguardOptions in Proguard ++= Seq("-dontnote", "-dontwarn", "-ignorewarnings")

proguardOptions in Proguard += ProguardOptions.keepMain("some.MainClass")

Run proguard at the sbt shell with:


Specifying the proguard version

In your build.sbt:

Proguard/proguardVersion := "6.2.2"

Or interactively in the sbt shell:

set myProject/Proguard/proguardVersion := "6.2.2"
show myProject/Proguard/proguardVersion

Available proguard versions:


Proguard supports file filtering for inputs, libraries, and outputs. In sbt-proguard there are File => Option[String] settings for adding filters to files.

For example, to add a !META-INF/** filter to just the scala-library jar:

proguardInputFilter in Proguard := { file => match {
    case "scala-library.jar" => Some("!META-INF/**")
    case _                   => None

which will create the following proguard configuration:

-injars "/path/to/scala-library.jar"(!META-INF/**)

There are corresponding settings for libraries and outputs: proguardLibraryFilter and proguardOutputFilter.

For more advanced usage the proguardFilteredInputs, proguardFilteredLibraries, and proguardFilteredOutputs settings can be set directly.


If the same path exists in multiple inputs then proguard will throw an error. The conflicting paths can be resolved using file filters, as described above, but this is not always the most useful approach. For example, reference.conf files for the Typesafe Config library need to be retained and not discarded.

The sbt-proguard plugin supports pre-merging inputs, similar to creating an assembly jar first. To enable this merging use:

proguardMerge in Proguard := true

Conflicting paths that are not identical will now fail at the merge stage. These conflicting paths can have merge strategies applied, similar to the sbt-assembly plugin.

Helper methods for creating common merges are available. These are:

  • discard -- discard all matching entries
  • first -- only keep the first entry
  • last -- only keep the last entry
  • rename -- rename entries adding the name of the source
  • append -- append entries together into one file

The paths matched against in these helpers are normalised to be separated by / regardless of platform. Paths can be matched exactly with a string or with a regular expression.

The default strategy is to only discard META-INF/MANIFEST.MF. This same strategy could be added with:

proguardMergeStrategies in Proguard += ProguardMerge.discard("META-INF/MANIFEST.MF")

Or all META-INF contents could be discarded with a regular expression:

proguardMergeStrategies in Proguard += ProguardMerge.discard("META-INF/.*".r)

To concatenate all reference.conf files together use:

proguardMergeStrategies in Proguard += ProguardMerge.append("reference.conf")

To discard all .html and .txt files you may use two strategies together:

proguardMergeStrategies in Proguard ++= Seq(

Completely custom merge strategies can also be created. See the plugin source code for how this could be done.

Sample projects

There are some runnable sample projects included as sbt scripted tests.

Contribution policy

Contributions via GitHub pull requests are gladly accepted from their original author. Before we can accept pull requests, you will need to agree to the Lightbend Contributor License Agreement online, using your GitHub account.


ProGuard is licensed under the GNU General Public License. sbt and sbt scripts are included in a special exception to the GPL licensing.

The code for this sbt plugin is licensed under the Apache 2.0 License.