diff --git a/frontend/packages/agent/src/app.js b/frontend/packages/agent/src/app.js
index 39ec8475..afd9abc9 100644
--- a/frontend/packages/agent/src/app.js
+++ b/frontend/packages/agent/src/app.js
@@ -548,6 +548,7 @@ window.marked = marked;
     { name: '/cancel',      desc: 'SIGINT the in-flight claude turn' },
     { name: '/compact',     desc: 'compact the persistent claude session' },
     { name: '/model',       desc: '/model <name>  — switch claude model for future turns' },
+    { name: '/effort',      desc: '/effort <level>  — set claude effort (medium/high/xhigh) for future turns' },
     { name: '/new-session', desc: 'next turn runs without --continue (fresh claude session)' },
     { name: '/logout',      desc: 'rotate OAuth credentials + park in needs-login (--continue session preserved)' },
   ];
@@ -668,6 +669,16 @@ window.marked = marked;
         }
         return true;
       }
+      case '/effort': {
+        const parts = trimmed.split(/\s+/);
+        if (parts.length < 2 || !parts[1]) {
+          termAPI.row('turn-end-fail',
+            '✗ /effort needs a level (e.g. /effort medium, /effort high, /effort xhigh)');
+        } else {
+          postEffort(parts[1]);
+        }
+        return true;
+      }
       default:
         termAPI.row('turn-end-fail', '✗ unknown slash command: ' + cmd + ' — try /help');
         return true;