---
title: "Reflection AI unveils Beam, a 501B open-weight coding model"
url: https://www.parallelquant.com/posts/reflection-ai-unveils-beam-a-501b-open-weight-coding-model-1ca568
source_name: "MarkTechPost"
source_url: https://www.marktechpost.com/2026/10/05/reflection-ai-introduces-beam-a-501b-open-weight-moe-model-with-23b-active-parameters-for-coding-and-agentic-workloads/
published: 2026-10-05T21:04:20.000Z
topics: ["llms", "open source"]
publisher: "Parallel Quant"
---

# Reflection AI unveils Beam, a 501B open-weight coding model

*2026-10-05 · Source: [MarkTechPost](https://www.marktechpost.com/2026/10/05/reflection-ai-introduces-beam-a-501b-open-weight-moe-model-with-23b-active-parameters-for-coding-and-agentic-workloads/)*

Reflection AI's first open-weight model is a 501B-parameter sparse Mixture-of-Experts (MoE) model with 23B active parameters, aimed at coding and agentic work. The company says it matches GLM-5.2 on reasoning with 3 to 4x less inference compute. Apache 2.0 weights are due later in October 2026.

**Why it matters:** A US lab shipping a permissively licensed frontier-scale open model puts it in direct competition with the Chinese open-weight models that currently dominate this tier. The pitch of cheaper inference and customizable local systems for institutions and governments fits the wider push for sovereign AI, though the efficiency claim is unverified until weights ship.

**Topics:** llms, open source

---
Read the original: https://www.marktechpost.com/2026/10/05/reflection-ai-introduces-beam-a-501b-open-weight-moe-model-with-23b-active-parameters-for-coding-and-agentic-workloads/
Canonical: https://www.parallelquant.com/posts/reflection-ai-unveils-beam-a-501b-open-weight-coding-model-1ca568
Published by Parallel Quant — https://www.parallelquant.com