This is the exact complete checkpoint used by Team caT's final MARS2 2026 formal inference run videochat3-whisper-inference-20260731-180133-9b3e95.

The exact checkpoint is stored under checkpoint-step-000900/ so its original README.md can remain part of the immutable content identity while this repository keeps a separate Hugging Face model card. adapter_config.json and adapter_model.safetensors in that directory are sufficient for the portable reproduction runner in the companion GitHub repository. The optimizer, rank RNG, training-state, completion marker, and checkpoint manifest files are included so reviewers can also verify the original complete checkpoint identity.

The PEFT config is preserved byte-for-byte and therefore contains the absolute base model path from the training host. The companion loader first materializes the base model from MCG-NJU/VideoChat3-4B and then loads this adapter; it does not depend on that historical host path. Point the reproduction command at model/checkpoint-step-000900 after downloading this repository.

No official leaderboard score is claimed here. Use of the adapter is subject to the base model's license and the MARS2 competition data terms.