Nemotron 3.5 Lightning

NVIDIA's compact execution model for long-running agents, designed to handle high-volume tool calls, result validation, and specialized tasks after larger models perform planning. It has 30B total / 3B active parameters in a hybrid Mamba-2 + Attention MoE: 52 backbone layers interleave Mamba-2, attention, and MoE blocks with 128 routed experts (top-6) plus one shared expert. Multi-Token Prediction (MTP) supplies an additional attention/MoE prediction layer and native speculative decoding.

The model was pretrained from scratch by NVIDIA on more than 20T tokens using an NVFP4 recipe, then continued-pretrained for MTP, supervised fine-tuned, and post-trained with asynchronous multi-environment GRPO across math, code, science, instruction following, multi-step tool use, multi-turn conversation, and structured-output tasks. It supports up to a 1M-token context and can deploy on one 80GB H100 or A100; BF16 reference, NVFP4 inference, pretrained-base, and DSpark/DFlash speculative-drafter checkpoints shipped under OpenMDW-1.1.

NVIDIA's reproducible release evaluation reports MMLU-Pro 81.94, GPQA Diamond 75.44, SWE-Bench Verified 51.56, Terminal-Bench 2.1 24.58, PinchBench 85.37, IFBench 71.88, and AA-LCR 52.0. NVIDIA positions Lightning below larger frontier planners but as a faster, customizable executor for always-on agent workflows, with reasoning enabled or disabled through its chat template.