14 APEX_CREDENTIAL
You can use the APEX_CREDENTIAL package to change stored credentials either persistently or for the current APEX session only. 
               
- CLEAR_TOKENS Procedure
 - CREATE_CREDENTIAL Procedure
 - DROP_CREDENTIAL Procedure
 - SET_ALLOWED_URLS Procedure
 - SET_PERSISTENT_CREDENTIALS Procedure Signature 1
 - SET_PERSISTENT_CREDENTIALS Procedure Signature 2
 - SET_PERSISTENT_TOKEN Procedure
 - SET_SESSION_CREDENTIALS Procedure Signature 1
 - SET_SESSION_CREDENTIALS Procedure Signature 2
 - SET_SESSION_CREDENTIALS Procedure Signature 3
 - SET_SESSION_TOKEN Procedure