In programming, the term dependency refers to a software component that is required by another piece of code to run.
What do you call the code that requires the dependency to run?
The opposite of a dependency is independency.
The inverse of a dependency is a dependent. This term applies specifically in programming to refer to the piece of code that requires the dependency to run.
The term is widely used. Some quotes to support the claim:
In the book Dependency Injection: Design patterns using Spring and Guice (so a book that is mainly about dependencies in the programming context):
Dependency — A specific service that is required by another object to fulfill its function.
Dependent — A client object that needs a dependency (or dependencies) in order to perform its function.
In the book The Unified Modeling Language Reference Manual, 2nd ed by Booch, Rumbaugh and Jacobson:
Dependency: A relationship between two elements in which a change to one element (the supplier) may affect or supply information needed by the other element (the client). (...) the dependent elements are called clients.
In the semantic versioning manifesto, they explain how semver can allow to release new versions of dependencies without disrupting dependent software or packages.
In the documentation of Maven:
Compile dependencies are available in all classpaths of a project. Furthermore, those dependencies are propagated to dependent projects.
Last but not least, linguist have also confirmed suitability of this term for very similar dependency management needs.
Dependency being a relation between something that is dependent and something that it depends on, there is a little residual ambiguity on the direction that is meant. Regardless the terms used, it's recommended to provide the definitions. Supplier/Client are alternatives that are imho more easily understood although not universally suitable.