WSO2 ESB: Simple Sequence To Send A Static XML Response. Link: http://www.mmdemirbas.com/2013/04/wso2-esb-simple-sequence-to-send-static.html

static_xml.xml

<sequence xmlns="http://ws.apache.org/ns/synapse" name="main" trace="disable">
    <in>
        <log level="headers">
            <property name="?" value="[main] in: started"/>
            <property name="To" expression="get-property('To')"/>
            <property name="PAYLOAD" expression="/*"/>
        </log>
        <script language="js"><![CDATA[
            mc.setPayloadXML(<greeting>Hello World</greeting>);
        ]]></script>
        <header name="To" action="remove"/>
        <property name="NO_ENTITY_BODY" action="remove" scope="axis2"/>
        <property name="RESPONSE" value="true"/>
        <send/>
        <log level="headers">
            <property name="?" value="[main] in: ended"/>
            <property name="PAYLOAD" expression="/*"/>
        </log>
    </in>
    <out>
        <log level="headers">
            <property name="?" value="[main] out: started"/>
            <property name="RESPONSE" expression="/*"/>
        </log>
        <send/>
        <log level="headers">
            <property name="?" value="[main] out: ended"/>
        </log>
    </out>
</sequence>