diff --git a/.gitea/workflows/build-ext.yml b/.gitea/workflows/build-ext.yml
index 4c0979b1..0fcb7c20 100644
--- a/.gitea/workflows/build-ext.yml
+++ b/.gitea/workflows/build-ext.yml
@@ -40,9 +40,21 @@ jobs:
             . ./.env.example
           fi
           set +a
-          echo "Environment NEXT_PUBLIC_* available:" || true
+          echo "Environment NEXT_PUBLIC_* available (current step):" || true
           env | grep '^NEXT_PUBLIC_' || true
 
+          # Exporter pour les étapes suivantes via GITHUB_ENV
+          count=0
+          while IFS='=' read -r key value; do
+            echo "$key=$value" >> "$GITHUB_ENV"
+            count=$((count+1))
+          done < <(env | grep '^NEXT_PUBLIC_')
+
+          if [ "$count" -eq 0 ]; then
+            echo "Aucune variable NEXT_PUBLIC_* détectée (ni .env/.env.example ni secrets). Abandon." >&2
+            exit 1
+          fi
+
       - name: Compute Docker tag from commit message or fallback
         id: tag
         shell: bash