autogluon/mitra-classifier-2

1---2license: apache-2.03pipeline_tag: tabular-classification4tags:5- arxiv:2609.045406---7 8# Mitra-v2 Classifier9 10Mitra-v2 classifier is a tabular foundation model that is pre-trained on purely synthetic datasets sampled from a mix of random classifiers, including the new Hybrid SCM prior. It is the second generation of the Mitra classifier ([autogluon/mitra-classifier](https://huggingface.co/autogluon/mitra-classifier)), pre-trained with a 10x longer context, three times as many features, and an improved optimizer. On the TabArena and TALENT benchmarks it delivers state-of-the-art accuracy at the level of TabFM and EXAONE Tabular, while surpassing TabPFN-3 by a wide margin. The regression model is at [autogluon/mitra-regressor-2](https://huggingface.co/autogluon/mitra-regressor-2), and the inference and fine-tuning code with our evaluation results is at [autogluon/mitra-finetune](https://huggingface.co/autogluon/mitra-finetune).11 12## Architecture13 14Mitra-v2 is based on a 12-layer 2D Transformer of 75.7 M parameters (attention across rows and across columns), pre-trained by incorporating an in-context learning paradigm. The architecture is unchanged from Mitra-v1; the gains come from the scaled-up synthetic pre-training distribution and the optimizer.15 16## Usage17 18To use Mitra-v2 classifier, install AutoGluon and the `mitra-finetune` package by running:19 20```sh21pip install uv22uv pip install "autogluon.tabular[mitra]>=1.6" "tabarena>=0.1.0"23uv pip install git+https://huggingface.co/autogluon/mitra-finetune24```25 26A minimal example showing how to fine-tune and predict with the Mitra-v2 classifier using the same recipe as our reported results (50-step fine-tuning with 8-fold bagging). The recipe fine-tunes and bags eight copies of the model and requires a CUDA GPU; each `predict_proba` or `predict` call runs one bagged fine-tune:27 28```python29import pandas as pd30from sklearn.model_selection import train_test_split31from sklearn.datasets import load_wine32from huggingface_hub import snapshot_download33from mitra_finetune import MitraFinetune34 35# Load dataset36wine_data = load_wine()37X = pd.DataFrame(wine_data.data, columns=wine_data.feature_names)38y = pd.Series(wine_data.target, name="target")39X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42, stratify=y)40 41# Download the Mitra-v2 classifier weights42ckpt_dir = snapshot_download("autogluon/mitra-classifier-2")43 44# Fine-tune and predict45model = MitraFinetune(checkpoint_dir=ckpt_dir, problem_type="classification")46model.fit(X_train, y_train)47proba = model.predict_proba(X_test)48pred = proba.argmax(axis=1)49print("Accuracy:", (pred == y_test.values).mean())50```51 52A minimal example showing how to perform inference with the Mitra-v2 classifier directly in AutoGluon (the weights are a drop-in replacement for the Mitra-v1 classifier):53 54```python55from autogluon.tabular import TabularDataset, TabularPredictor56 57train_data = TabularDataset(pd.concat([X_train, y_train], axis=1))58test_data = TabularDataset(pd.concat([X_test, y_test], axis=1))59 60mitra_predictor = TabularPredictor(label="target")61mitra_predictor.fit(62    train_data,63    hyperparameters={64        "MITRA": {"hf_model": "autogluon/mitra-classifier-2", "fine_tune": False}65    },66)67 68mitra_predictor.leaderboard(test_data)69```70 71Set `"fine_tune": True` to fine-tune inside AutoGluon. Note that AutoGluon's stock defaults differ from the `mitra-finetune` recipe used for the reported benchmark numbers.72 73## License74 75This project is licensed under the Apache-2.0 License.76 77## Reference78 79[Mitra-v2 Technical Report](https://arxiv.org/abs/2609.04540) (Amazon, 2026), also available on the [Hub](https://huggingface.co/autogluon/mitra-finetune/blob/main/Mitra_v2_Technical_Report.pdf).80 81```82@article{mitrav2_2026,83  title={{Mitra-v2} Technical Report},84  author={Tao, Yefan and Zhang, Xiyuan and Liu, Xinyi and Han, Boran and Maddix, Danielle and Fang, Haoyang and Han, Zhen and Gai, Jiading and Liu, Xuanqing and Bohlke-Schneider, Michael and Wang, Yuyang (Bernie) and Friedland, Gerald and Mah, Kevan and Lee, Chris and Kong, Chris},85  journal={arXiv preprint arXiv:2609.04540},86  year={2026}87}88```89 90The original Mitra:91 92```93@article{zhang2025mitra,94  title={Mitra: Mixed synthetic priors for enhancing tabular foundation models},95  author={Zhang, Xiyuan and Maddix, Danielle C and Yin, Junming and Erickson, Nick and Ansari, Abdul Fatir and Han, Boran and Zhang, Shuai and Akoglu, Leman and Faloutsos, Christos and Mahoney, Michael W and others},96  journal={arXiv preprint arXiv:2510.21204},97  year={2025}98}99```100 101Amazon Science blog: [Mitra: Mixed synthetic priors for enhancing tabular foundation models](https://www.amazon.science/blog/mitra-mixed-synthetic-priors-for-enhancing-tabular-foundation-models)102