diff --git a/frontend/packages/agent/src/app.js b/frontend/packages/agent/src/app.js
index 70db5adc..feedcce7 100644
--- a/frontend/packages/agent/src/app.js
+++ b/frontend/packages/agent/src/app.js
@@ -1431,11 +1431,38 @@ window.marked = marked;
       return false;
     }
     function renderStream(v, api) {
-      // Drop session init, claude's result line, rate-limit — noise.
-      // TurnEnd communicates pass/fail; session init isn't actionable.
-      if (v.type === 'system' && v.subtype === 'init') return;
+      // Drop claude's result line and rate-limit — noise. TurnEnd
+      // communicates pass/fail; rate-limit events are noisy status chatter.
       if (v.type === 'rate_limit_event') return;
       if (v.type === 'result') return;
+      // `system` events: `init` is silent startup noise; `api_retry`
+      // and `api_error` get human-readable notes; unknown subtypes get a
+      // muted line rather than a raw-JSON dump in the loud `sys` colour.
+      if (v.type === 'system') {
+        if (v.subtype === 'init') return;
+        if (v.subtype === 'api_retry') {
+          const parts = ['⚠ api retry'];
+          if (v.attempt != null && v.max_retries != null)
+            parts.push(v.attempt + '/' + v.max_retries);
+          if (v.error) parts.push(String(v.error));
+          else if (v.error_status) parts.push('HTTP ' + v.error_status);
+          if (v.retry_delay_ms != null)
+            parts.push(Math.round(v.retry_delay_ms) + 'ms');
+          api.row('note', parts.join(' · '));
+          return;
+        }
+        if (v.subtype === 'api_error') {
+          const msg = v.error || v.message
+            || (v.error_status ? 'HTTP ' + v.error_status : 'unknown');
+          api.row('note stderr', '✗ api error · ' + msg);
+          return;
+        }
+        // Other system subtypes (context_window_exceeded, etc.) — render a
+        // muted note with the subtype label; reserve the loud orange `sys`
+        // catch-all for truly unrecognised top-level types.
+        api.row('note', '⚙ ' + (v.subtype || 'system'));
+        return;
+      }
       // Background-task subagent events (claude's `Task` tool spawns
       // a separate session whose progress lands here as `task_*`
       // subtypes). Match by subtype so we don't have to track which