Hi Leonardo,
You can refer the following
https://supportforums.cisco.com/discussion/10754506/how-get-read-only-access-cucm-7-database
CUCM 8.x specific info is here
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/devguide/8_6_1/xmldev-861/axl.html#wp1055203
https://developer.cisco.com/media/manager-xml-developer-guide/index.html?versioning.html
HTH
Manish