diff --git a/frontend/src/main.js b/frontend/src/main.js
index 9c2dedf..1af24b6 100644
--- a/frontend/src/main.js
+++ b/frontend/src/main.js
@@ -742,7 +742,14 @@ async function handleCallback() {
         const response = await fetch(`${API_URL}/auth/callback?code=${code}&redirect_uri=${encodeURIComponent(AUTH_CONFIG.redirectUri)}`, {
             credentials: 'include'
         });
-        const data = await response.json();
+        const contentType = response.headers.get("content-type");
+        let data;
+        if (contentType && contentType.includes("application/json")) {
+            data = await response.json();
+        } else {
+            const text = await response.text();
+            throw new Error(`Expected JSON but got ${contentType}. Body: ${text.substring(0, 100)}`);
+        }
 
         if (response.ok) {
             state.isAuthenticated = true;
@@ -820,7 +827,12 @@ if ('serviceWorker' in navigator) {
                 console.log('SW registered', reg);
                 setupPush(reg);
             })
-            .catch(err => console.error('SW registration failed', err));
+            .catch(err => {
+                console.error('SW registration failed:', err);
+                if (window.isSecureContext === false) {
+                    console.error('Context is NOT secure. Service Workers require HTTPS or localhost.');
+                }
+            });
     });
 }
 
diff --git a/src/config.rs b/src/config.rs
index 5a1d6d6..b69a4c0 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -15,7 +15,6 @@ pub struct Config {
     pub agent_max_turns: u32,
     pub agent_max_duration_secs: u64,
     pub vapid_private_key: String,
-    pub vapid_public_key: String,
 }
 
 impl Config {
@@ -58,8 +57,6 @@ impl Config {
 
         let vapid_private_key = env::var("VAPID_PRIVATE_KEY")
             .map_err(|_| AppError::Config("VAPID_PRIVATE_KEY must be set".into()))?;
-        let vapid_public_key = env::var("VAPID_PUBLIC_KEY")
-            .map_err(|_| AppError::Config("VAPID_PUBLIC_KEY must be set".into()))?;
 
         Ok(Config {
             database_url,
@@ -74,7 +71,6 @@ impl Config {
             agent_max_turns,
             agent_max_duration_secs,
             vapid_private_key,
-            vapid_public_key,
         })
     }
 }