The Chemistry Development Kit
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The Chemical Development Kit (CDK)

Copyright 1997-2014 The CDK Development Team License: LGPL v2, see doc/lgpl.license


You are currently reading the README file for the Chemistry Development Project (CDK). This project is hosted under Please refer to these pages for updated information and the latest version of the CDK.

The CDK is an open-source library of algorithms for structural chemo- and bioinformatics, implemented in the programming language Java(tm). The library is published under terms of the the GNU Lesser General Public License v2. This has implications on what you can do with sources and binaries of the CDK library. For details, please refer to the file LICENSE, which should have been provided with this distribution.

PLEASE NOTE: This is a library of useful data structures and algorithms to manipulate them from the area of structural chemo- and bioinformatics. As such, it is intended for the use by programmers, who wish to save some effort by reusing code. It is not intended for the enduser. If you consider yourself to be more like user, you might not find what you wanted. Please refer to other projects like the JChemPaint project ( or the Jmol project ( for programs that actually take advantage of the CDK library.


Compiling the library is performed with Apache Maven and requires Java 1.6.0 or later:

cdk/$ ls pom.xml
cdk/$ pom.xml
cdk/$ mvn compile

This will produce a 'jar' file for each module located in each modules 'target/' directory.

Creating the JavaDoc documentation for the API

The JavaDoc documentation for the API describes all of the CDK classes in detail. It functions as the user manual for the CDK, although you should also look at the list of examples and tutorials below. This documentation is created by 'mvn' from the Java source code for the CDK as follows:

cdk/$ ls pom.xml
cdk/$ mvn javadoc:aggregate

The documenation is created as a series of .html pages in target/site/apidocs. If you use firefox, you can read the documentation using the following command:

cdk/$ firefox target/site/apidocs/index.html

Running tests

IMPORTANT: this requires the Git version of the sources, because the test files are not included in the source code distribution.

After you compiled the code, you can do "mvn test" to run the test suite of non-interactive, automated tests. Upon "mvn test", you should see something like:

test: Running org.openscience.cdk.test.CDKTests Tests run: 1065, Failures: 7, Errors: 1, Time elapsed: 27,55 sec

As you can see, the vast majority of tests ran successfully, but that there are failures and errors.

You can run the tests for an individual module by changing to the module directory:

cdk/$ cd descriptor/fingerprint
cdk/descriptor/fingerprint/$ mvn test

Tutorials on building the project in integrated development enviroments (IDEs) are avaialble on the wiki:

Using CDK

CDK is a class library intended to be used by other programs. It will not run as a stand-alone program, although it contains some GUI- and command line applications. If your project is also using maven you can install the library in your local repository (~/.m2/repository) as follows:

cdk/$ mvn install -Dmaven.test.failure.ignore=true

A large bundled jar with all dependencies can also be built. If you have locally made modifications to the source code you will need to install these to your local repository. The jar will in the target directory of the 'bundle' module.

cdk/$ mvn install -DskipTests=true cdk/$ ls bundle/target/cdk-{version}.jar

If you have not made any changes you need only package the bundle module. The other modules will be automatically downloaded.

cdk/$ cd bundle
cdk/$ mvn package
cdk/$ ls target/cdk-{version}.jar

Maven Artefacts

The Maven artefacts are currently deployed to the European Bioinformatics Institute (EMBL-EBI) remote repositories. To use the repositories from a maven project add the following configuration to you pom.xml.


You can then use a cdk module by specifying a dependency in the pom.xml. Any additional requirements of the module will also be included. The RELEASE specifies the latest released version whilst LATEST will provide the latest development build (snapshot). You may also specify a specific version.


Examples and tutorials

To get started using the CDK, you may be interested in the following websites which contain examples and tutorials:

To keep up with the latest news on CDK development and usage