Nanbeige4.2-3B

Nanbeige4.2-3B: A 3B-parameter agentic model outperforming 9B–12B models on agentic benchmarks

Researchers present Nanbeige4.2-3B, a 3-billion non-embedding parameter model designed for agentic tasks including code-agent, office-agent, and complex tool use. The model is pretrained on 28T tokens using a Looped Transformer architecture that reuses layer stacks to increase capacity without adding parameters, and trained with a multi-stage RL pipeline combining mixed-mode RLHF, length-controlled reasoning RL, and agentic RL with outcome and process rewards. Evaluations claim Nanbeige4.2-3B outperforms larger models including Qwen3.5-9B and Gemma4-12B on diverse agentic benchmarks while remaining competitive on reasoning tasks. The result contributes to the ongoing question of how much agentic capability can be packed into compact, locally-deployable models.