on (in) tap, on draught, ready for immediate consumption or use (literal and figurative); also spec. in Stock Market use, applied to securities…

to the fore: (Scottish and Anglo-Irish phrase, introduced into English literary use in the 19th cent.) Of money, etc.: Ready at or to hand…

Of a kind to be easily procured.

Easily obtainable, as at the press of a button; instant, immediate.

done or available when required or requested; providing or requiring a commodity, service, etc., on demand.