Reflection announces Beam, a 501B-parameter open-weight MoE for coding
Key points
- Full weights under Apache 2.0 are due this month. The text-only model has 23B active parameters per token.
- Team posts cite 23.8T pretraining tokens. Reflection's claimed 80.9 on SWE-bench Verified is unverified, and a tech report is promised.
- Observers reportedly place Beam around GLM-5.2 level and below DeepSeek V4 Flash on some benchmarks.
- Artificial Analysis, which had early access, expects Beam to be among the most token-efficient open models for its intelligence.
Why it matters for marketers: Content and marketing teams citing open-model benchmarks should wait for the promised weights and tech report before repeating Beam's self-reported scores.