Ultra-fast FLASH radiation therapy (FLASH-RT) is gaining wide acceptance as a major paradigm shift in cancer care resulting from pre-clinical and initial human studies. However, the lack of affordable clinical FLASH-RT systems along with the inability to measure and safely deliver the prescribed dose in real-time, has limited its wider clinical use. To overcome this, in Phase I, we have built and demonstrated the linear dosimetric behavior of an RF-based real-time beam monitor integrated into our electron-FLASH linear accelerator. The beam monitor was able to measure pulses in the order of a few microseconds and provide input to a control system that we developed in-house. The control system in turn was demonstrated to respond within a few milliseconds and was able to switch off the beam, or if needed, even modify the beam, based on the readout of the previous pulse. In Phase II, we will build five such linacs with integrated beam monitors and demonstrate the repeatability of the monitor and the updated control circuit. The beam monitor will also be tested on a photon-FLASH system that we will build. The final version will include diverse user feedback and will be presented to potential customers and the FDA.