US lab Reflection open-sourced Beam (501B MoE / 23B active, 1M context, Apache 2.0) for coding and long-horizon agents, with day-0 vLLM/SGLang/Transformers support, Mirror CLI harness, and 40+ inference partners including OpenRouter and Ollama.
Mirror is Reflection's early-beta coding agent for the terminal—defaults to Beam-1.0-501B-A23B, manual/auto tool approval, resumable conversations, parallel /worktree agents, AGENTS.md+skills+MCP/extensions, with provider keys kept out of the agent's shell environment.