The CAS Extension API provides interfaces and classes to build extensions to the Content Acquisition System such as data sources and manipulators. An extension developer packages extensions into a JAR, and a CAS application developer installs the JAR and any additional JARs (for third-party dependencies) into the Content Acquisition System. After installation, the extensions are available and configurable using the CAS Console, the CAS Server API, and the CAS Server Command-line Utility.