Fix

apps/sim/lib/copilot/client-sse/handlers.ts

@@ -332,13 +332,11 @@ export const sseHandlers: Record<string, SSEHandler> = {
           }
         }
 
-        if (targetState === ClientToolCallState.success) {
-          applyToolEffects({
-            effectsRaw: eventData.effects,
-            toolCall: updatedMap[toolCallId],
-            resultPayload,
-          })
-        }
+        applyToolEffects({
+          effectsRaw: eventData.effects,
+          toolCall: updatedMap[toolCallId],
+          resultPayload,
+        })
       }
 
       for (let i = 0; i < context.contentBlocks.length; i++) {

apps/sim/lib/copilot/client-sse/subagent-handlers.ts

@@ -358,13 +358,11 @@ export const subAgentSSEHandlers: Record<string, SSEHandler> = {
         })
       }
 
-      if (targetState === ClientToolCallState.success) {
-        applyToolEffects({
-          effectsRaw: resultData.effects,
-          toolCall: updatedSubAgentToolCall,
-          resultPayload,
-        })
-      }
+      applyToolEffects({
+        effectsRaw: resultData.effects,
+        toolCall: updatedSubAgentToolCall,
+        resultPayload,
+      })
     }
 
     updateToolCallWithSubAgentData(context, get, set, parentToolCallId)

apps/sim/lib/copilot/client-sse/tool-effects.ts

@@ -119,7 +119,21 @@ export function applyToolEffects(params: {
   resultPayload?: Record<string, unknown>
 }): void {
   const effects = parseToolEffects(params.effectsRaw)
-  if (effects.length === 0) return
+  if (effects.length === 0) {
+    if (params.toolCall?.name === 'workflow_change' && params.resultPayload) {
+      const workflowState = resolveWorkflowState({}, params.resultPayload)
+      if (!workflowState) return
+      useWorkflowDiffStore
+        .getState()
+        .setProposedChanges(workflowState)
+        .catch((error) => {
+          logger.error('Failed to apply fallback workflow diff from result payload', {
+            error: error instanceof Error ? error.message : String(error),
+          })
+        })
+    }
+    return
+  }
 
   for (const effect of effects) {
     switch (effect.kind) {
@@ -159,4 +173,3 @@ export function applyToolEffects(params: {
     }
   }
 }
-