Reflection has introduced Beam, a 501-billion-parameter text model that it says can match China’s GLM-5.2 on difficult reasoning benchmarks while using three to four times less compute at inference. The model is due to become open later this month, with its weights and full technical documentation. Those claims have not been independently verified, making Beam’s release less a settled challenge to closed labs than a test of whether Reflection can turn a striking efficiency pitch into a model others can reproduce and use.