diff --git a/crates/goose-server/src/routes/extension.rs b/crates/goose-server/src/routes/extension.rs
index 1ab49234..c327ea2b 100644
--- a/crates/goose-server/src/routes/extension.rs
+++ b/crates/goose-server/src/routes/extension.rs
@@ -21,6 +21,7 @@ enum ExtensionConfigRequest {
         /// The URI endpoint for the SSE extension.
         uri: String,
         /// List of environment variable keys. The server will fetch their values from the keyring.
+        #[serde(default)]
         env_keys: Vec<String>,
     },
     /// Standard I/O (stdio) extension.
@@ -31,8 +32,10 @@ enum ExtensionConfigRequest {
         /// The command to execute.
         cmd: String,
         /// Arguments for the command.
+        #[serde(default)]
         args: Vec<String>,
         /// List of environment variable keys. The server will fetch their values from the keyring.
+        #[serde(default)]
         env_keys: Vec<String>,
     },
     /// Built-in extension that is part of the goose binary.
diff --git a/ui/desktop/src/extensions.ts b/ui/desktop/src/extensions.ts
index 16ca4a29..a73237b4 100644
--- a/ui/desktop/src/extensions.ts
+++ b/ui/desktop/src/extensions.ts
@@ -290,7 +290,7 @@ export async function addExtensionFromDeepLink(url: string, navigate: NavigateFu
     args,
     description,
     enabled: true,
-    env_keys: Object.keys(envs).length > 0 ? Object.keys(envs) : undefined,
+    env_keys: Object.keys(envs).length > 0 ? Object.keys(envs) : [],
   };
 
   // Store the extension config regardless of env vars status