diff --git a/gemini-extension.json b/gemini-extension.json
index d791666..52b1f79 100644
--- a/gemini-extension.json
+++ b/gemini-extension.json
@@ -12,5 +12,22 @@
       ]
     }
   },
-  "contextFileName": "SPANNER.md"
+  "contextFileName": "SPANNER.md",
+  "settings": [
+    {
+      "name": "Project ID",
+      "description": "ID of the Google Cloud project",
+      "envVar": "SPANNER_PROJECT"
+    },
+    {
+      "name": "Instance ID",
+      "description": "ID of the Spanner instance",
+      "envVar": "SPANNER_INSTANCE"
+    },
+    {
+      "name": "Database ID",
+      "description": "ID of the Spanner database",
+      "envVar": "SPANNER_DATABASE"
+    }
+  ]
 }