Hello! We are happy to announce the *first Open Lab Online workshops *on *Bonsai*. *Bonsai* is an open-source reactive programming language that is particularly useful for modern behavioral neuroscience experiments. It allows users to synchronize multiple data streams, precisely deliver stimuli, and run experiments in closed-loop settings, while integrating signals and devices from different systems. From calcium imaging and sound recordings to sensors, feeders, motors, and stimulus delivery systems, Bonsai offers a flexible and powerful way to build experimental workflows. These workshops correspond to *Module I* of a *3-module online course of increasing difficulty*. In this first module, participants will be introduced to the basics of Bonsai — its logic, core principles, and potential applications. The workshop will also cover how to track animals during experiments, detect their presence in ROIs, run simple closed-loop paradigms, and perform basic logical operations. To make participation easier across schedules and time zones, we are offering *two alternative sessions of the same workshop*: *Session 1:* May 8, 2026, 10:00–12:00 CEST (UTC+2) https://nenckiopenlab.org/event/introduction-to-bonsai-module-i/ *Session 2:* May 18, 2026, 16:00–18:00 CEST (UTC+2) https://nenckiopenlab.org/event/introduction-to-bonsai-module-i-2/ *Requirements:* no prior programming experience is needed. A *Windows computer* and a *webcam* are required. *Workshop fee:* EUR 10 *Fee waivers are available upon request.* *Instructor:* Mateusz Kostecki, Heidelberg University We also warmly invite you to join our *Open Lab Online Discord*, which is a space for discussion, exchange, and community around open tools and methods. All important workshop information and updates will also be shared there. Discord: https://discord.gg/z7gvyj9yrV If you would like to get involved in Open Lab Online, you can also fill out our surveys: *Organizer survey*: https://docs.google.com/forms/d/e/1FAIpQLSeRqICetBCRbKZnjM9HlmLp1RKql3nUqxgu... *Instructor survey*: https://docs.google.com/forms/d/e/1FAIpQLSdDZioKGcDdsP7AFE6-mS6R_y7-kWTf6t2w... If you have any questions, feel free to contact us at *openlab@nencki.edu.pl* <openlab@nencki.edu.pl> or reach out to us on *Discord*. Best wishes, Mateusz Kostecki -- --- Mateusz Kostecki PhD Student Knapska Laboratory Nencki Institute 02-093 Warsaw, Pasteura 3, Poland https://twitter.com/mtkostecki https://evolvingbehavior.blog/