Acording to
addons/amxx/configs/core.ini the vault file (vault.ini) is
addons/amxx/configs/vault.ini, you don't need to create your own although you could if you wanted to

.
As for using the vault, it's pretty simple, you'll need to #include the vault include file, and there are four vault functions (read,write,remove,exists?).
Eg:
Code:
#include <vault>
/* store client's name in vault, indexed by authid,
if they already have name in vault, extract it first */
storeName(id) {
new newName[32], oldName[32] authid[32]
get_user_name(id,newName,31)
get_user_authid(id,authid,31)
if (vaultdata_exists(authid))
get_vaultdata(authid,oldName,31)
set_vaultdata(authid,newName)
}
/* remove client data from vault on disconnect */
public client_disconnect(id) {
new authid[32]
get_user_authid(id,authid,31)
if (vaultdata_exists(authid))
remove_vaultdata(authid)
}
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