Something like antonym for "dependent"

The dependent object would more context-appropriately be termed the

depender

(programming) An agent that depends on another agent, the dependee; the subject of a dependency, a dependent (used in agent-oriented programming)

Usage notes
Technical term, not widely used in software engineering outside of agent-oriented programming; the common term dependent is used instead. In agent-oriented programming, the antonym is dependee, though there is no common language equivalent (other metaphors are used instead, such as parent/child). Further, the circumlocutions “A depends on B” and “B is depended on by A” are used for clarity.

and the object on which the depender depends is termed the

dependee

(programming) An agent that is depended on by a depender, the target of a dependency (used in agent-oriented programming)

Usage notes
Technical term, not widely used in software engineering outside of agent-oriented programming but finds some use. In agent-oriented programming the antonym is depender, though in general usage the common term dependent is used instead. There is no common language equivalent for dependee, however – other metaphors are used instead, such as parent/child. The circumlocutions “A depends on B” and “B is depended on by A” are much more common in general use than “A is the depender, B is the dependee”.

src: Wikipedia

See also, related post What is the correct word for “dependee”? right here on ELU. Especially the answer by EvanK.