Key Info

Reflection AI unveiled Beam, a highly efficient agentic open model with 501B total parameters and 23B active parameters, trained end-to-end from scratch, with full weights release planned for this month.

Highlights

  • 501B total parameters, 23B active parameters, positioning it as a sparse efficient design
  • Marketed for frontier reasoning efficiency and agentic/coding tasks
  • Trained end-to-end from scratch, advancing the Western open frontier on coding and agentic tasks
  • Full weights release scheduled for later this month
  • Early open-source community reaction highlights Reflection AI's engineering-first contributions to transformers, vLLM, SGLang, TRL, and OpenEnv