fix(terminal): attribute repeated block output by invocation

apps/sim/app/api/workflows/[id]/execute/route.ts

@@ -1866,7 +1866,8 @@ async function handleExecutePost(
             blockType: string,
             executionOrder: number,
             iterationContext?: IterationContext,
-            childWorkflowContext?: ChildWorkflowContext
+            childWorkflowContext?: ChildWorkflowContext,
+            blockExecutionId?: string
           ) => {
             reqLogger.info('onBlockStart called', { blockId, blockName, blockType })
             await sendEvent({
@@ -1892,6 +1893,7 @@ async function handleExecutePost(
                   childWorkflowBlockId: childWorkflowContext.parentBlockId,
                   childWorkflowName: childWorkflowContext.workflowName,
                 }),
+                ...(blockExecutionId && { blockExecutionId }),
               },
             })
           }
@@ -1902,7 +1904,8 @@ async function handleExecutePost(
             blockType: string,
             callbackData: BlockCompletionCallbackData,
             iterationContext?: IterationContext,
-            childWorkflowContext?: ChildWorkflowContext
+            childWorkflowContext?: ChildWorkflowContext,
+            blockExecutionId?: string
           ) => {
             const compactCallbackData = {
               ...callbackData,
@@ -1982,6 +1985,9 @@ async function handleExecutePost(
                   }),
                   ...childWorkflowData,
                   ...instanceData,
+                  ...((blockExecutionId || callbackData.blockExecutionId) && {
+                    blockExecutionId: blockExecutionId ?? callbackData.blockExecutionId,
+                  }),
                 },
               })
             } else {
@@ -2021,13 +2027,17 @@ async function handleExecutePost(
                   }),
                   ...childWorkflowData,
                   ...instanceData,
+                  ...((blockExecutionId || callbackData.blockExecutionId) && {
+                    blockExecutionId: blockExecutionId ?? callbackData.blockExecutionId,
+                  }),
                 },
               })
             }
           }
 
           const onStream = async (streamingExec: StreamingExecution) => {
             const blockId = (streamingExec.execution as any).blockId
+            const { blockExecutionId } = streamingExec
 
             // Live answer text rides the sink when available (pending deltas
             // stream as the model generates; chunk_reset clears intermediate
@@ -2038,6 +2048,7 @@ async function handleExecutePost(
             // Sync window: attach sink before first await so pump delivers thinking/tools.
             const unsubscribe = forwardAgentStreamToExecutionEvents(streamingExec, {
               blockId,
+              blockExecutionId,
               executionId,
               workflowId,
               sendEvent,
@@ -2079,7 +2090,7 @@ async function handleExecutePost(
                   timestamp: new Date().toISOString(),
                   executionId,
                   workflowId,
-                  data: { blockId, chunk, display },
+                  data: { blockId, ...(blockExecutionId && { blockExecutionId }), chunk, display },
                 })
               }
 
@@ -2089,7 +2100,7 @@ async function handleExecutePost(
                   timestamp: new Date().toISOString(),
                   executionId,
                   workflowId,
-                  data: { blockId },
+                  data: { blockId, ...(blockExecutionId && { blockExecutionId }) },
                 })
               }
             } catch (error) {
@@ -2150,7 +2161,8 @@ async function handleExecutePost(
             childWorkflowInstanceId: string,
             iterationContext?: IterationContext,
             executionOrder?: number,
-            childWorkflowContext?: ChildWorkflowContext
+            childWorkflowContext?: ChildWorkflowContext,
+            blockExecutionId?: string
           ) => {
             await sendEvent({
               type: 'block:childWorkflowStarted',
@@ -2174,6 +2186,7 @@ async function handleExecutePost(
                   childWorkflowName: childWorkflowContext.workflowName,
                 }),
                 ...(executionOrder !== undefined && { executionOrder }),
+                ...(blockExecutionId && { blockExecutionId }),
               },
             })
           }

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.test.tsx

@@ -2,11 +2,13 @@
  * @vitest-environment jsdom
  */
 import { act, type ReactNode } from 'react'
+import { sleep } from '@sim/utils/helpers'
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
 import { createRoot, type Root } from 'react-dom/client'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 
 const {
+  chatStoreState,
   executionStoreState,
   mockCancel,
   mockExecute,
@@ -22,6 +24,9 @@ const {
   workflowBlocks,
   workflowStoreState,
 } = vi.hoisted(() => {
+  const chatStoreState = {
+    selectedWorkflowOutputs: [] as string[],
+  }
   const workflowBlocks = {
     start: {
       id: 'start',
@@ -82,6 +87,7 @@ const {
   }
 
   return {
+    chatStoreState,
     executionStoreState,
     mockCancel: vi.fn(),
     mockExecute: vi.fn(),
@@ -167,9 +173,18 @@ vi.mock('@/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-current-workflow
 
 vi.mock('@/app/workspace/[workspaceId]/w/[workflowId]/utils/workflow-execution-utils', () => ({
   addHttpErrorConsoleEntry: vi.fn(),
-  createBlockEventHandlers: () => ({
+  createBlockEventHandlers: (config: {
+    onBlockCompleteCallback?: (
+      blockId: string,
+      output: unknown,
+      blockExecutionId?: string
+    ) => Promise<void>
+  }) => ({
     onBlockStarted: vi.fn(),
-    onBlockCompleted: vi.fn(),
+    onBlockCompleted: vi.fn(
+      (data: { blockId: string; output: unknown; blockExecutionId?: string }) =>
+        config.onBlockCompleteCallback?.(data.blockId, data.output, data.blockExecutionId)
+    ),
     onBlockError: vi.fn(),
     onBlockChildWorkflowStarted: vi.fn(),
   }),
@@ -221,7 +236,7 @@ vi.mock('@/serializer', () => ({
 vi.mock('@/stores/chat/store', () => ({
   useChatStore: {
     getState: () => ({
-      getSelectedWorkflowOutput: () => [],
+      getSelectedWorkflowOutput: () => chatStoreState.selectedWorkflowOutputs,
     }),
   },
 }))
@@ -343,6 +358,7 @@ async function drainStream(value: unknown): Promise<void> {
 describe('useWorkflowExecution cancellation', () => {
   beforeEach(() => {
     vi.clearAllMocks()
+    chatStoreState.selectedWorkflowOutputs = []
     executionStoreState.getCurrentExecutionId.mockReturnValue('execution-1')
     mockRequestJson.mockResolvedValue({ success: true })
   })
@@ -402,6 +418,7 @@ describe('useWorkflowExecution cancellation', () => {
 describe('useWorkflowExecution attachment uploads', () => {
   beforeEach(() => {
     vi.clearAllMocks()
+    chatStoreState.selectedWorkflowOutputs = []
     executionStoreState.getCurrentExecutionId.mockReturnValue(null)
     mockResolveStartCandidates.mockReturnValue([])
     mockSelectBestTrigger.mockReturnValue([])
@@ -584,6 +601,52 @@ describe('useWorkflowExecution attachment uploads', () => {
     unmount()
   })
 
+  it('does not append a later sibling output after the block has streamed', async () => {
+    chatStoreState.selectedWorkflowOutputs = ['agent-1_content']
+    mockExecute.mockImplementationOnce(async (options) => {
+      options.onExecutionId?.('execution-1')
+      await options.callbacks?.onStreamChunk?.({
+        blockId: 'agent-1',
+        blockExecutionId: 'invoke-streamed',
+        chunk: 'streamed answer',
+      })
+      await sleep(0)
+      await options.callbacks?.onBlockCompleted?.({
+        blockId: 'agent-1',
+        blockExecutionId: 'invoke-streamed',
+        output: { content: 'streamed answer' },
+      })
+      await options.callbacks?.onBlockCompleted?.({
+        blockId: 'agent-1',
+        blockExecutionId: 'invoke-later',
+        output: { content: 'later answer' },
+      })
+    })
+
+    const { result, unmount } = renderWorkflowExecutionHook()
+    const decoder = new TextDecoder()
+    let streamedText = ''
+
+    await act(async () => {
+      const runResult = await result().handleRunWorkflow({ input: 'chat input' })
+      if (!isChatWorkflowRunResult(runResult)) {
+        throw new Error('Expected a chat workflow run result')
+      }
+      const reader = runResult.stream.getReader()
+      while (true) {
+        const { done, value } = await reader.read()
+        if (done) break
+        streamedText += decoder.decode(value, { stream: true })
+      }
+      streamedText += decoder.decode()
+    })
+
+    expect(streamedText).toContain('streamed answer')
+    expect(streamedText).not.toContain('later answer')
+
+    unmount()
+  })
+
   it('preserves legacy live thinking when no display projection field is sent', async () => {
     mockExecute.mockImplementationOnce(async (options) => {
       options.onExecutionId?.('execution-1')