{
  "schema_version": 1,
  "kind": "sa_wm_pretrained_model_release",
  "model_id": "sa_wm_pretrained_v1",
  "status": "selected_for_release_and_post_training",
  "selected_at": "2026-07-25",
  "selected_checkpoint": {
    "training_stage": "sa_wm_pretrain_v6_512x768",
    "micro_step": 55000,
    "path": "/mnt/cfs/wmcprg/RoboCoach/checkpoints/sa_wm_pretrain_v6_512x768/checkpoint-55000",
    "training_config": "configs/training/sa_wm_pretrain_v6.yaml",
    "weights": "dit_model.safetensors",
    "checkpoint_format": "safetensors+optim_shards",
    "post_training_load_mode": "model_only_init_from"
  },
  "selection_evidence": {
    "monitoring_selection": "/mnt/cfs/wmcprg/RoboCoach/checkpoints/sa_wm_pretrain_v6_512x768/validation/selection_closed_loop.json",
    "samples": 30,
    "rollout_chunks": 4,
    "future_frames": 1440,
    "metrics": {
      "psnr": 21.503524390835977,
      "ssim": 0.9163767135968223,
      "lpips_alex": 0.07815770965373506
    },
    "selection_reason": [
      "Human review preferred the motion and physical behavior of checkpoint-55000.",
      "DROID exterior_1 and exterior_2 PSNR, SSIM, and LPIPS all outperform checkpoint-70000.",
      "The fourth closed-loop chunk is slightly better than checkpoint-70000 in PSNR and LPIPS.",
      "The aggregate metric difference from checkpoint-70000 is too small to override the qualitative review."
    ]
  },
  "historical_comparison": {
    "checkpoint": "/mnt/cfs/wmcprg/RoboCoach/checkpoints/sa_wm_pretrain_v6_512x768/checkpoint-70000",
    "micro_step": 70000,
    "status": "retained_late_training_reference_not_selected",
    "metrics": {
      "psnr": 21.552308871443916,
      "ssim": 0.9175402801300698,
      "lpips_alex": 0.07684179975799957
    }
  },
  "usage_contract": {
    "inference": "load selected_checkpoint/dit_model.safetensors",
    "post_training": "initialize model weights from the selected checkpoint and start a new optimizer, scheduler, step counter, output directory, and run id",
    "exact_v6_resume": "allowed only for reproducing the historical v6 stage; do not use it for domain post-training",
    "immutability": "never overwrite the selected checkpoint directory"
  }
}