Reflection releases Beam, a 501B open coding model under Apache 2.0

Reflection has released Beam, an open-weight model for coding and agent work under the Apache 2.0 licence, with a launch guide from Hugging Face. It is a mixture-of-experts model with 501B total parameters and about 23B active per token, text only, with a 1M token context window, and comes with its own open-source Rust-based agent harness. Reflection's own figures for the BF16 version include 66.1% on SWE Bench Pro v1 and 80.1% on Terminal Bench v2.1, not yet independently tested. Hugging Face suggests serving the 4-bit NVFP4 checkpoint, about 280 GB, on four B200 GPUs, or trying it through Inference Providers. Reflection is also offering $10,000 in Hub credits for the best projects built on it. Sorted take: a permissive licence makes this a real option for teams that want to own and fine-tune a coding model, but most should try a hosted endpoint before buying GPUs.