Reflection Releases Beam Open Weights Model With Launch-Day vLLM Support

Latent Space’s AINews recap covers DeepSeek V4.1 Flash 1017, MiniMax M3.1 Flash, and Mercury 3, while noting they are not yet expected to see very wide use. It reports that DeepSeek’s model has a 1M-token context window and scores 45 on the Artificial Analysis Intelligence Index, tying GLM-5.3 for second among open-weight models. The recap also includes benchmark results, pricing, availability, and caveats for the releases.

Reflection-Beam-1.0 from @reflection_ai has Day-0 support in vLLM. 501B total parameters, 23B active per token, and a 1M-token context window. Beam combines hybrid attention with Harmony-format reasoning and tool use. Beam also has Day-0 RL support in SkyRL (@NovaSkyAI): https://t.co/3SjWJKKgpH https://t.co/EkmA1L6B3H

Reflection’s first model, Beam, scores 30 on the Artificial Analysis Intelligence Index, placing it #2 among US open weights models. Beam is an open weights model with 501B total and 23B active parameters, released on Hugging Face.

Reflection-Beam-1.0 has Day-0 support in vLLM, with 501B total parameters, 23B active per token, and a 1M-token context window. Beam combines hybrid attention with Harmony-format reasoning and tool use, and has Day-0 RL support in SkyRL through LoRA, BF16 full fine-tuning and MXFP8 RL, with vLLM rollouts. vLLM worked with Reflection and Inferact on the serving path, from fused kernels to DFlash.

Reflection released Beam on Hugging Face, a 501B MoE model with 23B active parameters per token, a 1M-token context window, and an Apache 2.0 license. The text-only model targets coding and agentic work, with BF16, FP8, and NVFP4 checkpoints and day-0 support in transformers, vLLM, and SGLang. Hugging Face provides deployment and post-training recipes alongside its own task evaluations and demos.