.z.wo:f

Where

• f is a unary function
• h is the handle to a websocket connection to a kdb+ session

f[h] is evaluated when the connection has been initialized, i.e. after it has been validated against any -u/-U file and .z.pw checks. (Since V3.3t 2014.11.26)

The handle argument is typically used by f to build a dictionary of handles to session information such as the value of .z.a, .z.u.