diff --git a/.github/workflows/build-xpi.yml b/.github/workflows/build-xpi.yml
index cca8598..e7183b0 100644
--- a/.github/workflows/build-xpi.yml
+++ b/.github/workflows/build-xpi.yml
@@ -1,4 +1,4 @@
-name: Build XPI
+name: Build & Sign XPI
 
 on:
   push:
@@ -8,15 +8,14 @@ on:
       - "fix/**"
     paths:
       - "src/**"
-  workflow_dispatch:
 
 jobs:
   build:
-    name: Package extension
+    name: Package, sign and release
     runs-on: ubuntu-latest
 
     permissions:
-      contents: write   # nécessaire pour créer la release et uploader l'artefact
+      contents: write   # nécessaire pour créer la release GitHub
 
     steps:
       # ---------------------------------------------------------------
@@ -26,41 +25,95 @@ jobs:
         uses: actions/checkout@v4
 
       # ---------------------------------------------------------------
-      # 2. Lire la version depuis manifest.json
+      # 2. Installer Node.js + web-ext (outil officiel Mozilla)
+      # ---------------------------------------------------------------
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+
+      - name: Install web-ext
+        run: npm install -g web-ext
+
+      # ---------------------------------------------------------------
+      # 3. Lire la version depuis manifest.json
       # ---------------------------------------------------------------
       - name: Read version
         id: version
         run: |
           VERSION=$(jq -r '.version' src/manifest.json)
           echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
-          echo "xpi_name=ytptube-extension-${VERSION}.xpi" >> "$GITHUB_OUTPUT"
+          echo "unsigned_xpi=ytptube-extension-${VERSION}.xpi" >> "$GITHUB_OUTPUT"
+          echo "signed_xpi=ytptube-extension-${VERSION}-signed.xpi" >> "$GITHUB_OUTPUT"
 
       # ---------------------------------------------------------------
-      # 3. Construire le XPI (= zip renommé)
+      # 4. Construire le XPI non signé (lint + zip)
       # ---------------------------------------------------------------
-      - name: Build XPI
+      - name: Lint extension
+        run: web-ext lint --source-dir src/
+
+      - name: Build unsigned XPI
         run: |
-          cd src
-          zip -r "../${{ steps.version.outputs.xpi_name }}" . \
-            -x "*.git*" "*.DS_Store" "*.idea*" "*.vscode*" \
-               "node_modules/*" "dist/*" "build/*"
-          cd ..
+          web-ext build \
+            --source-dir src/ \
+            --artifacts-dir dist/ \
+            --filename "${{ steps.version.outputs.unsigned_xpi }}" \
+            --overwrite-dest
           echo "Contenu du XPI :"
-          unzip -l "${{ steps.version.outputs.xpi_name }}"
+          unzip -l "dist/${{ steps.version.outputs.unsigned_xpi }}"
 
       # ---------------------------------------------------------------
-      # 4. Uploader comme artefact CI (disponible dans l'onglet Actions)
+      # 5. Uploader le XPI non signé comme artefact CI
+      #    (toutes branches, utile pour debug)
       # ---------------------------------------------------------------
-      - name: Upload artifact
-        uses: actions/upload-artifact@v3
+      - name: Upload unsigned artifact
+        uses: actions/upload-artifact@v4
         with:
-          name: ${{ steps.version.outputs.xpi_name }}
-          path: ${{ steps.version.outputs.xpi_name }}
+          name: ${{ steps.version.outputs.unsigned_xpi }}
+          path: dist/${{ steps.version.outputs.unsigned_xpi }}
           retention-days: 30
 
       # ---------------------------------------------------------------
-      # 5. Créer ou mettre à jour la pre-release "latest-dev"
-      #    (uniquement sur la branche main)
+      # 6. Signer via l'API Mozilla AMO (uniquement sur main)
+      #    Requiert les secrets AMO_JWT_ISSUER et AMO_JWT_SECRET
+      # ---------------------------------------------------------------
+      - name: Sign XPI with Mozilla
+        if: github.ref == 'refs/heads/main'
+        id: sign
+        env:
+          AMO_JWT_ISSUER: ${{ secrets.AMO_JWT_ISSUER }}
+          AMO_JWT_SECRET: ${{ secrets.AMO_JWT_SECRET }}
+        run: |
+          web-ext sign \
+            --source-dir src/ \
+            --artifacts-dir dist/ \
+            --api-key "$AMO_JWT_ISSUER" \
+            --api-secret "$AMO_JWT_SECRET" \
+            --channel unlisted
+          
+          # web-ext sign produit un fichier signé dans dist/ — on le retrouve
+          SIGNED=$(find dist/ -name "*.xpi" ! -name "${{ steps.version.outputs.unsigned_xpi }}" | head -1)
+          if [ -z "$SIGNED" ]; then
+            echo "Aucun XPI signé trouvé, on utilise l'unsigned en fallback"
+            SIGNED="dist/${{ steps.version.outputs.unsigned_xpi }}"
+          fi
+          cp "$SIGNED" "dist/${{ steps.version.outputs.signed_xpi }}"
+          echo "signed_path=dist/${{ steps.version.outputs.signed_xpi }}" >> "$GITHUB_OUTPUT"
+
+      # ---------------------------------------------------------------
+      # 7. Uploader le XPI signé comme artefact CI
+      # ---------------------------------------------------------------
+      - name: Upload signed artifact
+        if: github.ref == 'refs/heads/main'
+        uses: actions/upload-artifact@v3
+        with:
+          name: ${{ steps.version.outputs.signed_xpi }}
+          path: ${{ steps.sign.outputs.signed_path }}
+          retention-days: 90
+
+      # ---------------------------------------------------------------
+      # 8. Créer ou mettre à jour la pre-release "latest-dev" sur main
+      #    avec le XPI signé en pièce jointe
       # ---------------------------------------------------------------
       - name: Create or update dev release
         if: github.ref == 'refs/heads/main'
@@ -68,16 +121,27 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           TAG="latest-dev"
-          XPI="${{ steps.version.outputs.xpi_name }}"
+          XPI="${{ steps.sign.outputs.signed_path }}"
           SHORT_SHA="${GITHUB_SHA::7}"
-          TITLE="Dev build v${{ steps.version.outputs.version }} (${SHORT_SHA})"
+          VERSION="${{ steps.version.outputs.version }}"
+          TITLE="Dev build v${VERSION} (${SHORT_SHA})"
 
           # Supprimer l'ancienne release/tag si elle existe
           gh release delete "$TAG" --yes 2>/dev/null || true
           git push --delete origin "$TAG" 2>/dev/null || true
 
-          # Recréer la release pre-release avec le nouveau XPI
+          # Recréer la release pre-release avec le XPI signé
           gh release create "$TAG" "$XPI" \
             --title "$TITLE" \
-            --notes "Build automatique du commit \`${SHORT_SHA}\` sur \`main\`." \
-            --prerelease
\ No newline at end of file
+            --notes "$(cat <<NOTES
+          ## Dev build v${VERSION}
+
+          Commit : \`${SHORT_SHA}\` sur \`main\`
+
+          ### Installation sur Firefox Android
+          1. Ouvrir Firefox Android
+          2. Aller sur cette page de release et télécharger le \`.xpi\`
+          3. Firefox installe automatiquement l'extension (signée Mozilla ✓)
+          NOTES
+          )" \
+            --prerelease