Model Description
Sage-A1.5-UD-4bit-fp16 inherits the full capability stack of Sage-A1.5 — agentic orchestration, verification mode, tool use, and open scientific discovery reasoning — while consuming a fraction of the memory. It is designed for long-horizon task execution with sub-agent delegation, evidence validation, and exploratory research across domains.
Base model
Quantization details
- Scheme: per-layer affine INT4 (
mode: affine, group_size: 64)
- Mixed precision: some blocks are kept at INT8 to preserve accuracy where it matters most:
- INT4:
switch_mlp (gating), plus MTP layers' gate/down/up — the largest memory savings come from the MoE switch FFN.
- INT8:
lm_head, embed_tokens, all linear_attn projections, and all shared_expert MLP weights.
- Output size: ~20.6 GB (5 shards, 4 GiB each +
model-mtp.safetensors), vs ~67 GB full precision.
- Activation dtype: the model itself runs in FP16/BF16 at runtime; only weights are quantized.
Architecture
Table with columns: Parameter, Value| Parameter | Value |
|---|
| Architecture | Qwen3_5MoeForConditionalGeneration |
| Layer type | MoE Transformer with switch FFN + linear attention hybrid |
| Hidden size | 2048 |
| Number of layers | 40 (linear attention / full attention: 3/1 per block) |
| Attention heads | 16 (GQA, 2 KV heads) |
| Head dim | 256 (16 linear key heads @ 128 + 32 linear value heads @ 128) |
| Vocabulary size | 248,320 |
| Max sequence length | 262,144 (256K) |
| RoPE theta | 10,000,000 (partial rotary factor 0.25) |
| RoPE layout | mRoPE interleaved, sections [11, 11, 10] |
| MoE experts | 256 total, 8 active per token |
| Expert FFN hidden size | 512 (switch MLP) / 512 (shared expert) |
| Vision encoder hidden size | 1152 → 2048 (out) |
| Norm | RMSNorm, eps 1e-6 |
| Init std | 0.02 |
Capabilities
- Agentic Orchestration — delegates tasks to sub-agents with isolated contexts, decomposes complex problems and synthesizes results.
- Verification Mode — opt-in self-review mid-trajectory (requires
chat_template_kwargs: {"verification": true} and a non-empty system message).
- Tool Use — native function calling / tool integration, API and code interpreter compatible.
- Vision & Video — image and video understanding via the Qwen3.5-style vision tower (image token 248056, video token 248057).
- Long context — supports up to 256K tokens with mRoPE (text/image/video).
- Scientific & professional reasoning — designed for long-horizon scientific discovery, code engineering, and research tasks.
The base model Sage-A1.5 (unquantized) achieves:
- 🥇 Overall SOTA on XBench-DS-2510 (92.0), IFBench (81.6), PinchBench (90.0), FrontierScience-Olympiad (81.0), FrontierScience-Research (48.3), CMT (80.0), OmniDocBench (91.5)
- 🟢 Best among comparable ~35B models on BrowseComp (81.7), SWE-bench Pro (61.2), MLE-Lite (65.2), SciCode (44.3), AA-LCR (81.0), HLE w/ tools (55.1), VitaBench (45.4), ChemCOTBench (66.5)
- 95.1 on GAIA — higher than every larger-scale model compared against
See the Sage-A1.5 README for the full evaluation table (GAIA, BrowseComp, DeepResearch-Bench2, SWE-bench Pro/Multilingual, HiPhO, CritPt, ALE-CLI, MatTools).
Usage
Load with Transformers (4.57+) in safetensors format:
from transformers import AutoModelForCausalLM, AutoTokenizer model = AutoModelForCausalLM.from_pretrained( "NapYang/Sage-A1.5-UD-4bit-fp16", # your repo name device_map="auto", torch_dtype=torch.float16,)tokenizer = AutoTokenizer.from_pretrained("NapYang/Sage-A1.5-UD-4bit-fp16")
Recommended sampling parameters (from base model card):
temperature: 1.0
top_p: 0.95
top_k: 20
min_p: 0.0
presence_penalty: 1.5
repetition_penalty: 1.0
Verification Mode (self-review)
Pass a non-empty system message plus chat_template_kwargs: {"verification": true}; the model pauses mid-trajectory and reviews its own chain of thought. Read reasoning_content in addition to content.
message = model.chat( tokenizer, messages=[ {"role": "system", "content": "You are a helpful assistant."}, {"role": "user", "content": "Find the population of Beijing and cross-check it."}, ], tools=TOOLS, chat_template_kwargs={"verification": True},)print(message.reasoning_content) # self-review happens inside the chain of thoughtprint(message.content)
Limitations
- Quantized weights trade a small amount of accuracy (usually <1% on standard benchmarks) for ~3× lower memory footprint; report your use case-specific validation.
- The model is multimodal — image/video input requires the full processor (
PreTrainedProcessor) from the base repo, not just the tokenizer.
- Tool use and verification mode rely on the base model's chat template (
chat_template.jinja); make sure to load it alongside this checkpoint.
- This checkpoint is provided as-is; the base model license (Apache 2.0) applies to all derivatives.
Citation
If you find our work helpful, feel free to give us a cite.
@misc{lou2026sagea15longhorizonexecutionscientific, title={Sage-A1.5: From Long-Horizon Execution to Scientific Exploration with Capability Composition}, author={Sage-A1.5 Team}, year={2026}, eprint={2610.28578}, archivePrefix={arXiv}, primaryClass={cs.AI}, url={https://arxiv.org/abs/2610.28578},}
Acknowledgements
This model is a derivative of InternScience/Sage-A1.5 (Shanghai AI Laboratory, Apache 2.0). Base model built on Qwen3.6 (Alibaba Cloud, Apache 2.0) and Agents-A1.