We incorporate logic programs (in particular Prolog) into reactive systems. We do this using Logic-labeled finitestate machines (LLFSMs), whose non-event-driven nature results in a deterministic schedule. We also advocate the use of a middleware under the Pull-approach, as opposed to the, currently very common, Push-approach, achieving deterministic semantics and the ability to ensure correctness in both the time and value domains. The deterministic schedule has other advantages, such as bounded resource use for inter-process communication as well as a smaller state space for formal verification. We demonstrate this architecture through a simple case study, contrasting the current prevalent Push approach in ROS [1] with the Pull approach recommended for LLFSMs.