diff --git a/vibn-frontend/app/api/chat/route.ts b/vibn-frontend/app/api/chat/route.ts
index 853ef8cf..f31f3725 100644
--- a/vibn-frontend/app/api/chat/route.ts
+++ b/vibn-frontend/app/api/chat/route.ts
@@ -964,9 +964,17 @@ export async function POST(request: Request) {
             extraSystem += `\n\n[WARNING] You only have ${maxToolRounds - round} tool calls left before you are forcefully terminated. Stop exploring, make your final edits, and write your final response to the user NOW.`;
           }
 
+          // Execute tool calls and add results. OpenAI-compatible APIs
+          const resp = await callVibnChat({
+            systemPrompt: systemPrompt + extraSystem,
+            messages,
+            tools: toolDefs,
+            temperature: 0.7,
+            includeThoughts: true,
+          });
+
           // C-08: Force Checkpoint Before Mutation
-          // If the AI is trying to use mutating tools but hasn't emitted a checkpoint,
-          // intercept the tool calls, block them, and force it to state its plan.
+          // (Moved safely *after* callVibnChat so 'resp' is defined)
           const requestedMutations = resp.toolCalls.filter((tc) =>
             [
               "fs_write",
@@ -1010,15 +1018,6 @@ export async function POST(request: Request) {
             });
           }
 
-          // Execute tool calls and add results. OpenAI-compatible APIs
-          const resp = await callVibnChat({
-            systemPrompt: systemPrompt + extraSystem,
-            messages,
-            tools: toolDefs,
-            temperature: 0.7,
-            includeThoughts: true,
-          });
-
           if (resp.error) {
             emit({ type: "error", error: resp.error });
             safeClose();