Reflection AI releases Beam, a 501B open-weight model
Nvidia-backed Reflection AI launched Beam, a 501B-parameter (23B active) MoE text model with a 1M-token context, aimed at coding, reasoning and agent workloads, with open weights under Apache 2.0 planned this month.
Nvidia-backed Reflection AI has launched Beam, a 501B-parameter open-weight AI model built for coding, reasoning and AI-agent workloads. Beam is aimed at competing with leading open-weight models from China. Beam is a text-only mixture-of-experts model with: • 501B total parameters, 23B active • 1M-token context window • Pretrained on 23.8T tokens • Built for coding, reasoning, tool use and agentic workloads Reflection says Beam performs comparably with Z .ai’s GLM-5.2 on advanced reasoning benchmarks while using 3-4x less inference compute. The company’s benchmark claims have not yet been independently verified. Beam’s reinforcement-learning run used 10,500 NVIDIA $NVDA GB300 GPUs for four weeks and generated more than 100M rollouts. Its base model was pretrained on 6,144 GB300 GPUs in under four weeks. Reflection is targeting enterprises, developers and sovereign governments, with a broader strategy around customized “AI factories” that can connect organizations’ proprietary data to locally controlled AI systems. The NVIDIA-backed startup has also signed more than $7B worth of compute deals with SpaceX and Nebius $NBIS to secure access to GB300 infrastructure through 2029. Reflection plans to release Beam’s weights under an Apache 2.0 license later this month, along with its technical report, model card and tools for running, evaluating and fine-tuning the model.