Reflection opens Beam under Apache 2.0: a 501B-total, 23B-active MoE for coding and agents with a 1M context
The first model from the new US lab Reflection, with a clearly stated license: its size, scores and what it takes to serve.
// Key points
- 501B total parameters with 23B active per token, text-only input, a 1M context, released under Apache 2.0 in BF16, FP8 and NVFP4 checkpoints.
- Reflection’s BF16 scores: 81.6% on SWE-bench Verified, 80.1% on Terminal Bench v2.1, 80.8% on MCP Atlas and 90.6% on GPQA Diamond.
- The BF16 checkpoint is about 1 TB and NVFP4 about 280 GB; Hugging Face suggests four B200s, and FP8 for GPUs older than Blackwell.
- Day-0 support in transformers, SGLang and vLLM; AWS listed it in SageMaker JumpStart in two US East Regions the same day.
Builder's takeCompared with Muse Spark Open on 10-16, Beam’s big difference is a stated Apache 2.0 license, which makes it the first frontier-class open coding model I’d put on a self-hosting shortlist. Four B200s means it’s only for teams with the hardware; I’d first run it through an inference provider on real tasks from my own repos, compare per-task cost with closed models, then decide whether to host it.
// Background · from #Open models
Full timeline →- Oct 17 IBM releases Granite Switch 4.1 in 8B and 30B: chat, decisions and speech-to-text from one endpoint, using about the base model’s VRAM
- Oct 17 Black Forest Labs opens FLUX.3 Image Klein: text-to-image, multi-reference editing and bounding-box layout in one model, about 2 seconds per 1024 image on an H100
- Oct 16 Meta releases open weights for Muse Spark Open, an 816B-total, 42B-active multimodal MoE with a 1M context