The SyncGenie is a programmable synchronization device designed for a range of uses in neuroscience research. With its default firmware, it is a configurable stand-alone “trigger box” that enables neurophysiological data to be aligned with physical stimulus events. It can also be re-programmed for a wide range of other applications: for example, to support both hardware-triggered and software-triggered pulse synchronization, to measure audio or video latencies, to deliver trigger pulses on uniquely custom-programmed schedules, or even to serve as a cost-effective digitizer for real-time analysis of analog signals. This is an open-source hardware device (per [OSHWA certification number US002698][1]). The printed circuit-board design file, 3D-printable model for the enclosure, components list, assembly instructions, Arduino library, example firmware, and instruction manual are all provided here on OSF. The assembly instructions are in the article preprint, which describes the SyncGenie's motivation, manufacture, and performance in a typical use case; this article has also been published by the Elsevier journal HardwareX under [doi 10.1016/j.ohx.2024.e00619][2] . The lead designer can be reached at ludvik.alkhoury@gmail.com [1]: https://certification.oshwa.org/us002698.html [2]: https://doi.org/10.1016/j.ohx.2024.e00619