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 or Eyeo GmbH.

The source code can be found at GitHub and is distributed under the terms of GNU General Public License Version 3, GNU Lesser General Public License Version 3, Apache License 2.0.

Quick Start

flattr4j is available at Maven Central. Just add this snippet to your pom.xml:



flattr4j needs at least Java 1.6 or Android API level 11 (earlier levels do not work because they do not support SNI).

flattr4j version 2 requires the json.org reference library. If you use Maven, the dependency is loaded automatically. Android API provides it, so flattr4j-core does not need additional libraries on Android devices.

Up to version 2.11, flattr4j also required Apache HttpComponents 4.