diff --git a/.gitea/workflows/build-ext.yml b/.gitea/workflows/build-ext.yml
new file mode 100644
index 00000000..0476a367
--- /dev/null
+++ b/.gitea/workflows/build-ext.yml
@@ -0,0 +1,64 @@
+name: build-and-push-ext
+
+on:
+  push:
+    branches:
+      - dev4
+
+jobs:
+  build_push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Prepare SSH agent (optional)
+        shell: bash
+        run: |
+          set -euo pipefail
+          eval "$(ssh-agent -s)"
+          if [ -n "${{ secrets.SSH_PRIVATE_KEY || '' }}" ]; then
+            echo "${{ secrets.SSH_PRIVATE_KEY }}" | tr -d '\r' | ssh-add - >/dev/null 2>&1 || true
+          fi
+          mkdir -p ~/.ssh
+          ssh-keyscan git.4nkweb.com >> ~/.ssh/known_hosts 2>/dev/null || true
+          echo "SSH agent ready: $SSH_AUTH_SOCK"
+
+      - name: Compute Docker tag from commit message or fallback
+        id: tag
+        shell: bash
+        run: |
+          set -euo pipefail
+          msg=$(git log -1 --pretty=%B)
+          if [[ "$msg" =~ ci:\ docker_tag=([a-zA-Z0-9._:-]+) ]]; then
+            tag="${BASH_REMATCH[1]}"
+          else
+            tag="dev-test"
+          fi
+          echo "TAG=$tag" | tee -a $GITHUB_OUTPUT
+
+      - name: Docker login (git.4nkweb.com)
+        shell: bash
+        env:
+          REG_USER: ${{ secrets.USER }}
+          REG_TOKEN: ${{ secrets.TOKEN }}
+        run: |
+          set -euo pipefail
+          echo "$REG_TOKEN" | docker login git.4nkweb.com -u "$REG_USER" --password-stdin
+
+      - name: Build image (target ext)
+        shell: bash
+        env:
+          DOCKER_BUILDKIT: "1"
+        run: |
+          set -euo pipefail
+          docker build --target ext --ssh default -t git.4nkweb.com/4nk/lecoffre-front:${{ steps.tag.outputs.TAG }} -f Dockerfile .
+
+      - name: Push image
+        shell: bash
+        run: |
+          set -euo pipefail
+          docker push git.4nkweb.com/4nk/lecoffre-front:${{ steps.tag.outputs.TAG }}
+