diff --git a/.github/workflows/build-default-big-model.yaml b/.github/workflows/build-default-big-model.yaml
new file mode 100644
index 0000000000..1a734a3af8
--- /dev/null
+++ b/.github/workflows/build-default-big-model.yaml
@@ -0,0 +1,82 @@
+name: Build default big model
+
+on:
+  push:
+    branches: [ master, master-dev ]
+    paths:
+      - 'openpilot/selfdrive/modeld/models/big_driving_supercombo.onnx'
+  workflow_dispatch:
+
+env:
+  HF_REPO: sunnypilot/sunnypilot_models_v1
+  HF_DEFAULTS_PATH: models/defaults/big
+
+jobs:
+  build_model:
+    uses: ./.github/workflows/sunnypilot-build-model.yaml
+    with:
+      upstream_branch: ${{ github.sha }}
+      custom_name: default-big-model
+      target_hardware: usbgpu
+    secrets: inherit
+
+  upload_defaults:
+    needs: build_model
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+      - run: git lfs pull -I "openpilot/selfdrive/modeld/models/big_driving_supercombo.onnx"
+
+      - name: Install huggingface_hub
+        run: pip install --upgrade "huggingface_hub>=0.22.0"
+
+      - name: Download artifact name
+        uses: actions/download-artifact@v4
+        with:
+          name: artifact-name-default-big-model
+          path: artifact_name
+
+      - name: Read artifact name
+        id: artifact
+        run: |
+          ARTIFACT_NAME=$(cat artifact_name/artifact_name.txt)
+          echo "artifact_name=$ARTIFACT_NAME" >> $GITHUB_OUTPUT
+
+      - name: Download model artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ steps.artifact.outputs.artifact_name }}
+          path: output
+
+      - name: Upload model to HF defaults
+        env:
+          HF_OIDC_RESOURCE: datasets/${{ env.HF_REPO }}
+          ARTIFACT_NAME: ${{ steps.artifact.outputs.artifact_name }}
+        run: |
+          rm -f output/artifact_name.txt
+          hf upload ${{ env.HF_REPO }} \
+            output/ \
+            "${HF_DEFAULTS_PATH}/${ARTIFACT_NAME}/" \
+            --repo-type=dataset
+
+      - name: Get tinygrad ref and ONNX hash
+        id: meta
+        run: |
+          export PYTHONPATH=$(pwd)
+          echo "tinygrad_ref=$(python3 openpilot/sunnypilot/models/tinygrad_ref.py)" >> $GITHUB_OUTPUT
+          echo "onnx_sha256=$(sha256sum openpilot/selfdrive/modeld/models/big_driving_supercombo.onnx | cut -d' ' -f1)" >> $GITHUB_OUTPUT
+
+      - name: Update default_models.json on HF
+        env:
+          HF_OIDC_RESOURCE: datasets/${{ env.HF_REPO }}
+          ARTIFACT_NAME: ${{ steps.artifact.outputs.artifact_name }}
+        run: |
+          python3 release/ci/upload_default_model.py \
+            --hf-repo "${{ env.HF_REPO }}" \
+            --hf-defaults-path "${{ env.HF_DEFAULTS_PATH }}" \
+            --artifact-name "$ARTIFACT_NAME" \
+            --metadata-path "output/metadata.json" \
+            --onnx-sha256 "${{ steps.meta.outputs.onnx_sha256 }}" \
+            --tinygrad-ref "${{ steps.meta.outputs.tinygrad_ref }}"
diff --git a/release/ci/upload_default_model.py b/release/ci/upload_default_model.py
new file mode 100644
index 0000000000..ab31dcabce
--- /dev/null
+++ b/release/ci/upload_default_model.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+"""
+Copyright (c) 2021-, Haibin Wen, sunnypilot, and a number of other contributors.
+
+This file is part of sunnypilot and is licensed under the MIT License.
+See the LICENSE.md file in the root directory for more details.
+"""
+
+import argparse
+import json
+import sys
+import tempfile
+
+from huggingface_hub import HfApi, hf_hub_download
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument("--hf-repo", required=True)
+  parser.add_argument("--hf-defaults-path", required=True)
+  parser.add_argument("--artifact-name", required=True)
+  parser.add_argument("--metadata-path", required=True)
+  parser.add_argument("--onnx-sha256", required=True)
+  parser.add_argument("--tinygrad-ref", required=True)
+  args = parser.parse_args()
+
+  with open(args.metadata_path) as f:
+    metadata = json.load(f)
+
+  bundle = metadata['bundles'][0]
+  bundle['onnx_sha256'] = args.onnx_sha256
+
+  artifact = bundle['models'][0]['artifact']
+  hf_base = f"https://huggingface.co/datasets/{args.hf_repo}/resolve/main/{args.hf_defaults_path}/{args.artifact_name}"
+  artifact['download_uri']['url'] = f"{hf_base}/{artifact['file_name']}"
+  for chunk in artifact.get('chunks', []):
+    chunk['url'] = f"{hf_base}/{chunk['file_name']}"
+
+  json_filename = f"{args.hf_defaults_path}/default_models.json"
+  try:
+    local_path = hf_hub_download(repo_id=args.hf_repo, repo_type='dataset', filename=json_filename)
+    with open(local_path) as f:
+      defaults_json = json.load(f)
+  except Exception:
+    defaults_json = {"tinygrad_ref": args.tinygrad_ref, "bundles": []}
+
+  defaults_json['tinygrad_ref'] = args.tinygrad_ref
+
+  existing_idx = next((i for i, b in enumerate(defaults_json['bundles'])
+                       if b.get('display_name') == bundle.get('display_name')), None)
+  if existing_idx is not None:
+    defaults_json['bundles'][existing_idx] = bundle
+  else:
+    defaults_json['bundles'].append(bundle)
+
+  print(json.dumps(defaults_json, indent=2))
+
+  api = HfApi()
+  with tempfile.NamedTemporaryFile(mode='w', suffix='.json', delete=False) as f:
+    json.dump(defaults_json, f, indent=2)
+    tmp_path = f.name
+
+  api.upload_file(
+    path_or_fileobj=tmp_path,
+    path_in_repo=json_filename,
+    repo_id=args.hf_repo,
+    repo_type="dataset",
+  )
+
+  print(f"Updated {json_filename}")
+
+
+if __name__ == "__main__":
+  main()