ultralytics/docs/en/reference/utils/callbacks/hub.md

description	keywords
Explore detailed guides on Ultralytics callbacks, including pretrain, model save, train start/end, and more. Enhance your ML training workflows with ease.	Ultralytics, callbacks, pretrain, model save, train start, train end, validation, predict, export, training, machine learning

Reference for ultralytics/utils/callbacks/hub.py

!!! note

This file is available at [https://github.com/ultralytics/ultralytics/blob/main/ultralytics/utils/callbacks/hub.py](https://github.com/ultralytics/ultralytics/blob/main/ultralytics/utils/callbacks/hub.py). If you spot a problem please help fix it by [contributing](https://docs.ultralytics.com/help/contributing/) a [Pull Request](https://github.com/ultralytics/ultralytics/edit/main/ultralytics/utils/callbacks/hub.py) 🛠️. Thank you 🙏!

::: ultralytics.utils.callbacks.hub.on_pretrain_routine_start

---

::: ultralytics.utils.callbacks.hub.on_pretrain_routine_end

---

::: ultralytics.utils.callbacks.hub.on_fit_epoch_end

---

::: ultralytics.utils.callbacks.hub.on_model_save

---

::: ultralytics.utils.callbacks.hub.on_train_end

---

::: ultralytics.utils.callbacks.hub.on_train_start

---

::: ultralytics.utils.callbacks.hub.on_val_start

---

::: ultralytics.utils.callbacks.hub.on_predict_start

---

::: ultralytics.utils.callbacks.hub.on_export_start