, News summary

Reflection releases Beam, a 501B-parameter open model for coding agents

Reflection, a new US lab, has released Beam as an open model on Hugging Face, aimed at coding and agent work on teams’ own hardware.

At a glance

total parameters
501B
active parameters per token
23B
token context window
1M
What’s new
Beam is Reflection’s first model: a text-only mixture-of-experts model under the Apache 2.0 licence, with day-one support in transformers, vLLM and SGLang.
Who it affects
AI teams and companies that want to run and customise a large model on their own servers or cloud.

The details

A mixture-of-experts model splits its network into many specialist parts and uses only a few for each token, so it runs faster than its size suggests. Beam still needs the memory of its full size: Hugging Face suggests planning for four Nvidia B200 GPUs to serve its compressed 4-bit version. It ships with its own Rust-based harness, plus recipes for fine-tuning and reinforcement learning. On Reflection’s own figures, it scores 81.6% on SWE-bench Verified, a coding test. Reflection is offering $10,000 in Hub credits for the best projects built with it.

Why it matters

Most frontier-scale models are rented through APIs. An openly licensed model of this size lets companies keep code and data in-house and tailor the model to their own work. The catch is cost: running it still takes several top-end GPUs. The benchmark scores come from Reflection itself, so independent tests will show whether Beam holds up against closed coding models.

Original source

Welcome Beam: a 501B open model you can own, customize, and scale

Hugging Face · huggingface.co

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