Skip to content
Java and Android client for Flattr API
Latest commit 56dc7e1 @shred Move issue tracker to GitHub
Failed to load latest commit information.
flattr4j-async Add missing for async module
flattr4j-spring-social Move documentation from wiki to git
src/site Move documentation from wiki to git
.gitignore Ignore Eclipse classpath files
.project Changes for Eclipse Indigo
LICENSE-APL.txt First import
LICENSE-GPL.txt First import
LICENSE-LGPL.txt First import Move documentation from wiki to git
pom.xml Move issue tracker to GitHub

Java Flattr Client build status

flattr4j is a free open source Java library for using the Flattr API and adding Flattr buttons to JSP web sites.

It primarily targets for business grade Flattr integration, e.g. on servers, web sites and full-featured desktop applications, but it can also be used on Android devices.

flattr4j is not endorsed by or affiliated with Flattr AB.

Important Note

Flattr is currently changing its API. Because of that, some of the flattr4j calls are failing or not delivering the expected results. It is unclear to me what a future API may look like, and to what extend flattr4j is going to support it. For the time being, I recommend not to use flattr4j in new projects.

Are you getting a "Received fatal alert: handshake_failure" exception? OpenJDK does not seem to support any of the Flattr server's cipher suites. Use the Oracle JDK instead!


  • Lightweight and easy to use
  • Covers the entire Flattr API
  • Also runs on Android
  • JSP tag library for inserting static and javascript Flattr buttons
  • Helps through the OAuth authentication process at Flattr, no OAuth knowledge is needed
  • With Maven and Spring support
  • Spring Social provider available (currently beta)




flattr4j is open source software. The source code is distributed under the terms of GNU General Public License Version 3, GNU Lesser General Public License Version 3, Apache License 2.0.

Something went wrong with that request. Please try again.