New Model: Reflection Beam is a new Open Weight Model

Summary

This session announces Reflection Beam, a new open-weight model designed for advanced agentic use cases and coding. The discussion details Beam's technical strengths—including high token efficiency and robust reasoning—and outlines the comprehensive ecosystem built around it. Key components include the 'Mirror' agentic coding harness and integrations across major platforms (e.g., VLLM, SG Lang). The session concludes by promoting 'Beam Build,' a hackathon encouraging the community to build and fine-tune projects using the model.

Technical details

• Model Architecture & Training 1200s

  Beam was trained on a massive dataset of 23 trillion tokens. The training process emphasizes meticulous curation of educational quality across sources (PDFs, code, essays) and utilizes advanced RL techniques to shape cognitive skills like self-verification and backtracking.

• Agentic Capabilities & Harnesses 1400s

  The 'Mirror' harness is the dedicated agentic coding tool, built upon an internal harness called 'Daedalus.' The model's ability to generalize across different harnesses (e.g., Pi, Open Code) is a key feature, suggesting a strong foundation for open-source adaptation.

• Optimization and Deployment 350s

  Beam is optimized for various hardware and precision levels, including BF16, FP8, and NVFP4. Deployment can be managed via first-party APIs, or optimized using inference engines like VLLM, SG Lang, and Nvidia AutoModel (for SFT).

• Fine-Tuning and Customization 600s

  Customization can involve Supervised Fine-Tuning (SFT) using TRL (Hugging Face library) or Reinforcement Learning (RL) using TRL/Miles. The process requires a tight loop involving data sourcing, environment creation, and evaluation to ensure high data quality and prevent reward hacking.

Mentioned resources

• Reflection Beam Model (Open Weight Model)
• Hugging Face Transformers (Library/Framework)
• Mirror Harness (Agentic Coding Tool)
• Beam Build (Hackathon/Competition)

Channel & topics

• Hugging Face
• Large Language Models (LLMs)
• Agentic AI
• Open Source AI
• Reinforcement Learning (RL)
• Model Quantization
• AI Infrastructure
• Reflection Beam Model
• Hugging Face Transformers
• Mirror Harness
• Beam Build