diff --git a/README.md b/README.md
index 84eb809..5691379 100644
--- a/README.md
+++ b/README.md
@@ -60,9 +60,16 @@ Since secrets and database files shouldn't be in Git, you need to place them on
 5. Under **Environment variables**, add the following:
    - `HOST_PATH`: `/opt/bookapp` (The folder you created in Step 2)
    - `GEMINI_API_KEY`: `<your-api-key>`
+   - `ADMIN_USERNAME`: `admin` (Or your preferred username)
    - `ADMIN_PASSWORD`: `<secure-password-for-web-ui>`
    - `FLASK_SECRET_KEY`: `<random-string>`
    - `FLASK_DEBUG`: `False` (Set to `True` only for troubleshooting)
+   
+   **Optional (Advanced / Vertex AI):**
+   - `GCP_PROJECT`: Your Google Cloud Project ID (Required for Imagen 3/Vertex AI).
+   - `GCP_LOCATION`: `us-central1` (Default).
+   - `MODEL_LOGIC`: Override the logic model (e.g., `models/gemini-1.5-pro-latest`).
+   - `MODEL_WRITER`: Override the writer model.
 6. Click **Deploy the stack**.
 
 Portainer will pull the code from Git, build the image, and mount the secrets/data from your server folder.
diff --git a/docker-compose.yml b/docker-compose.yml
index 7166f2a..9ffd978 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -27,7 +27,13 @@ services:
       - PYTHONUNBUFFERED=1
       - GOOGLE_APPLICATION_CREDENTIALS=/app/credentials.json
       - PYTHONPATH=/app
-      - FLASK_SECRET_KEY=change_this_to_a_random_string
-      - ADMIN_USERNAME=admin
-      - ADMIN_PASSWORD=change_me_in_portainer
-      - GEMINI_API_KEY=${GEMINI_API_KEY}
\ No newline at end of file
+      - FLASK_SECRET_KEY=${FLASK_SECRET_KEY:-change_this_to_a_random_string}
+      - ADMIN_USERNAME=${ADMIN_USERNAME:-admin}
+      - ADMIN_PASSWORD=${ADMIN_PASSWORD:-change_me_in_portainer}
+      - FLASK_DEBUG=${FLASK_DEBUG:-False}
+      - GEMINI_API_KEY=${GEMINI_API_KEY}
+      - GCP_PROJECT=${GCP_PROJECT:-}
+      - GCP_LOCATION=${GCP_LOCATION:-us-central1}
+      - MODEL_LOGIC=${MODEL_LOGIC:-AUTO}
+      - MODEL_WRITER=${MODEL_WRITER:-AUTO}
+      - MODEL_ARTIST=${MODEL_ARTIST:-AUTO}
\ No newline at end of file