KAT-Coder-V2.5-Dev (GGUF Quantizations)
This repository contains Importance-Matrix (imatrix) quantized GGUF files for Kwaipilot/KAT-Coder-V2.5-Dev.
KAT-Coder-V2.5-Dev is an open-weight, post-trained Mixture-of-Experts (MoE) coding agent model featuring 35B total parameters with 3B activated parameters per token, fine-tuned on top of Qwen3.6-35B-A3B.
⚠️ Note: This open-weight release contains only language-model weights and operates as a text-only model. Vision/multimodal components are not included.
📦 Provided GGUF Files
All quantizations in this repository were converted using llama.cpp and optimized using an imatrix (Importance Matrix) calibration file to maintain high performance at lower precision levels.
| Filename | Size | Description / Recommendation |
|---|---|---|
KAT-Coder-V2.5-Dev-IQ3_XXS.gguf |
14.9 GB | Extreme 3-bit compression. Lowest VRAM/RAM requirement. |
KAT-Coder-V2.5-Dev-IQ3_XS.gguf |
16.2 GB | High-compression 3-bit quant with imatrix tuning. |
KAT-Coder-V2.5-Dev-Q3_K_M.gguf |
16.2 GB | Standard 3-bit medium quantization. |
KAT-Coder-V2.5-Dev-IQ3_M.gguf |
16.9 GB | Balanced 3-bit quantization with strong reasoning retention. |
KAT-Coder-V2.5-Dev-IQ4_XS.gguf |
18.8 GB | Great choice for systems with ~20 GB VRAM/RAM. |
KAT-Coder-V2.5-Dev-IQ4_NL.gguf |
19.9 GB | Non-linear 4-bit quantization optimized via imatrix. |
KAT-Coder-V2.5-Dev-Q4_K_S.gguf |
20.6 GB | Small 4-bit quantization. |
KAT-Coder-V2.5-Dev-Q4_K_M.gguf |
21.4 GB | Recommended. Optimal balance of speed, size, and perplexity for 24GB GPUs. |
KAT-Coder-V2.5-Dev-Q5_K_S.gguf |
24.2 GB | 5-bit small quantization with higher fidelity. |
KAT-Coder-V2.5-Dev-Q5_K_M.gguf |
25.0 GB | High Quality. Near-lossless output; suitable for 32GB+ systems. |
KAT-Coder-V2.5-Dev-Q6_K.gguf |
30.1 GB | High-precision 6-bit quant for power users. |
KAT-Coder-V2.5-Dev-Q8_0.gguf |
36.9 GB | Virtually identical to full 16-bit float precision. |
🚀 Quickstart & Usage
Running with llama.cpp
Ensure you are using a recent build of llama.cpp that supports Qwen3 / MoE architectures.
CLI Example:
./llama-cli -m KAT-Coder-V2.5-Dev-Q4_K_M.gguf \
-p "Write a Python function that implements a binary search tree with deletion." \
-n 4096 \
-c 32768 \
--temp 0.7
Launching an OpenAI-Compatible API Server:
./llama-server -m KAT-Coder-V2.5-Dev-Q4_K_M.gguf \
--host 0.0.0.0 \
--port 8000 \
-c 262144 \
-ngl 99
GUI Frontends (LM Studio, KoboldCpp, Jan)
- Download your preferred
.gguffile from the table above. - Place the file inside your local model folder (e.g.,
~/.cache/lm-studio/modelsor KoboldCpp directory). - Set your context size up to 262,144 tokens (adjust depending on your available system RAM/VRAM).
✨ Original Model Highlights
- SOTA Agentic Coding Performance: Through post-training SFT and RL, KAT-Coder-V2.5-Dev achieves state-of-the-art results among models of similar parameter scales on benchmark tasks like SWE-bench Verified (69.40%).
- Reduced Pathological Behaviors: Reinforcement Learning significantly reduced unwanted behaviors, such as abnormal tool labels (-9pp improvement) and single-turn continuous repetitions (reduced to 0%).
- Preserve Thinking Mode: The model supports retaining historical thinking context across multi-turn interactions, improving agent consistency and saving redundant reasoning tokens.
📊 Benchmark Performance
The table below shows the official benchmark evaluation results reproduced in-house by the original authors:
| Benchmark | KAT-Coder-V2.5-Dev | Qwen3.5-27B | Qwen3.6-35BA3B | Gemma4-31B | Qwen3.5-35BA3B | Ornith-1.0-35B | Gemma4-26BA4B | Qwen3-Coder-30B |
|---|---|---|---|---|---|---|---|---|
| SWE-bench Verified | 69.40 | 68.60 | 64.40 | 60.60 | 58.60 | 55.80 | 35.80 | 31.80 |
| SWE-bench Multilingual | 63.00 | 57.67 | 57.00 | 49.33 | 47.67 | 51.67 | 27.33 | 20.67 |
| SWE-bench Pro | 45.96 | 42.13 | 40.63 | 32.97 | 38.03 | 34.47 | 9.58 | 19.84 |
| Terminal-Bench 2.1 | 41.02 | 34.84 | 32.02 | 32.59 | 26.12 | 35.98 | 20.94 | 13.50 |
| PinchBench | 93.43 | 90.71 | 92.21 | 85.53 | 88.75 | 91.62 | 82.01 | 72.30 |
| Scicode | 44.20 | 25.58 | 37.53 | 33.19 | 27.73 | 30.34 | 30.84 | 18.27 |
| KAT-Code-Bench | 46.21 | 44.83 | 42.76 | 37.93 | 35.86 | 33.10 | 22.06 | 15.17 |
🔬 Post-Training Details
KAT-Coder-V2.5-Dev follows a two-stage post-training pipeline built on top of Qwen3.6-35B-A3B:
- Supervised Fine-Tuning (SFT): Fine-tuned on 127K curated agentic and coding examples.
- Reinforcement Learning (RL):
- Token-in-Token-out (TITO) Consistency: Eliminates off-policy training discrepancies caused by tokenizer or chat-template changes.
- Truncated Importance Sampling (TIS): Mitigates policy staleness during asynchronous rollout collection.
- Reliable Execution Feedback: Built using verified sandbox execution for dense and reliable reward signals.
- Specific Penalties: Introduced targeted reward penalties against abnormal parallel tool calling (70+ tool calls in one turn), failed calls, and loops.
📜 Citation
If you use KAT-Coder-V2.5-Dev or these GGUF quantizations in your work, please cite the technical report:
@misc{katcoder_v25_2026,
title={{KAT-Coder-V2.5 Technical Report}},
author={{KwaiKAT Team}},
year={2026},
month={July},
eprint={2607.05471},
archivePrefix={arXiv},
primaryClass={cs.AI},
url={[https://arxiv.org/pdf/2607.05471](https://arxiv.org/pdf/2607.05471)}
}
Original model created by the KwaiKAT Team / Kwaipilot. Quantized to GGUF format by Abiray.