Reflection AI introduces 501B Beam open-weight model to challenge Chinese AI rivals

Reflection AI introduced Beam, its first open-weight model, moving a well-funded U.S. startup into direct competition with Chinese labs that have dominated the open-model frontier. The company says Beam is a 501B-parameter sparse Mixture-of-Experts model built for coding, reasoning and agentic workloads, with weights and technical materials promised later in October.