# The Client Classpath Apache ActiveMQ Artemis requires several jars on the *Client Classpath* depending on whether the client uses Apache ActiveMQ Artemis Core API, JMS, and JNDI. > **Warning** > > All the jars mentioned here can be found in the `lib` directory of the > Apache ActiveMQ Artemis distribution. Be sure you only use the jars from the correct > version of the release, you *must not* mix and match versions of jars > from different Apache ActiveMQ Artemis versions. Mixing and matching different jar > versions may cause subtle errors and failures to occur. ## Apache ActiveMQ Artemis Core Client If you are using just a pure Apache ActiveMQ Artemis Core client (i.e. no JMS) then you need `activemq-core-client.jar`, `activemq-commons.jar`, and `netty.jar` on your client classpath. ## JMS Client If you are using JMS on the client side, then you will also need to include `activemq-jms-client.jar` and `geronimo-jms_2.0_spec.jar`. > **Note** > > `geronimo-jms_2.0_spec.jar` just contains Java EE API interface classes needed > for the `javax.jms.*` classes. If you already have a jar with these > interface classes on your classpath, you will not need it.