feat(child-workflows): nested execution snapshots

apps/sim/app/api/logs/execution/[executionId]/route.ts

@@ -6,7 +6,7 @@ import {
   workflowExecutionSnapshots,
 } from '@sim/db/schema'
 import { createLogger } from '@sim/logger'
-import { and, eq } from 'drizzle-orm'
+import { and, eq, inArray } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { checkHybridAuth } from '@/lib/auth/hybrid'
 import { generateRequestId } from '@/lib/core/utils/request'
@@ -48,6 +48,7 @@ export async function GET(
         endedAt: workflowExecutionLogs.endedAt,
         totalDurationMs: workflowExecutionLogs.totalDurationMs,
         cost: workflowExecutionLogs.cost,
+        executionData: workflowExecutionLogs.executionData,
       })
       .from(workflowExecutionLogs)
       .innerJoin(workflow, eq(workflowExecutionLogs.workflowId, workflow.id))
@@ -78,10 +79,44 @@ export async function GET(
       return NextResponse.json({ error: 'Workflow state snapshot not found' }, { status: 404 })
     }
 
+    const traceSpans =
+      (workflowLog.executionData as { traceSpans?: Array<{ [key: string]: unknown }> })
+        ?.traceSpans || []
+    const childSnapshotIds = new Set<string>()
+    const collectSnapshotIds = (spans: Array<{ [key: string]: unknown }>) => {
+      spans.forEach((span) => {
+        const snapshotId = span.childWorkflowSnapshotId
+        if (typeof snapshotId === 'string') {
+          childSnapshotIds.add(snapshotId)
+        }
+        const children = span.children
+        if (Array.isArray(children)) {
+          collectSnapshotIds(children as Array<{ [key: string]: unknown }>)
+        }
+      })
+    }
+    if (traceSpans.length > 0) {
+      collectSnapshotIds(traceSpans)
+    }
+
+    const childWorkflowSnapshots =
+      childSnapshotIds.size > 0
+        ? await db
+            .select()
+            .from(workflowExecutionSnapshots)
+            .where(inArray(workflowExecutionSnapshots.id, Array.from(childSnapshotIds)))
+        : []
+
+    const childSnapshotMap = childWorkflowSnapshots.reduce<Record<string, unknown>>((acc, snap) => {
+      acc[snap.id] = snap.stateData
+      return acc
+    }, {})
+
     const response = {
       executionId,
       workflowId: workflowLog.workflowId,
       workflowState: snapshot.stateData,
+      childWorkflowSnapshots: childSnapshotMap,
       executionMetadata: {
         trigger: workflowLog.trigger,
         startedAt: workflowLog.startedAt.toISOString(),

apps/sim/app/workspace/[workspaceId]/logs/components/log-details/components/execution-snapshot/execution-snapshot.tsx

@@ -80,6 +80,9 @@ export function ExecutionSnapshot({
   }, [executionId, closeMenu])
 
   const workflowState = data?.workflowState as WorkflowState | undefined
+  const childWorkflowSnapshots = data?.childWorkflowSnapshots as
+    | Record<string, WorkflowState>
+    | undefined
 
   const renderContent = () => {
     if (isLoading) {
@@ -148,6 +151,7 @@ export function ExecutionSnapshot({
         key={executionId}
         workflowState={workflowState}
         traceSpans={traceSpans}
+        childWorkflowSnapshots={childWorkflowSnapshots}
         className={className}
         height={height}
         width={width}

apps/sim/app/workspace/[workspaceId]/w/components/preview/components/preview-editor/preview-editor.tsx

@@ -690,6 +690,7 @@ interface ExecutionData {
   output?: unknown
   status?: string
   durationMs?: number
+  childWorkflowSnapshotId?: string
 }
 
 interface WorkflowVariable {
@@ -714,6 +715,8 @@ interface PreviewEditorProps {
   parallels?: Record<string, Parallel>
   /** When true, shows "Not Executed" badge if no executionData is provided */
   isExecutionMode?: boolean
+  /** Child workflow snapshots keyed by snapshot ID (execution mode only) */
+  childWorkflowSnapshots?: Record<string, WorkflowState>
   /** Optional close handler - if not provided, no close button is shown */
   onClose?: () => void
   /** Callback to drill down into a nested workflow block */
@@ -739,6 +742,7 @@ function PreviewEditorContent({
   loops,
   parallels,
   isExecutionMode = false,
+  childWorkflowSnapshots,
   onClose,
   onDrillDown,
 }: PreviewEditorProps) {
@@ -768,17 +772,31 @@ function PreviewEditorContent({
   const { data: childWorkflowState, isLoading: isLoadingChildWorkflow } = useWorkflowState(
     childWorkflowId ?? undefined
   )
+  const childWorkflowSnapshotId = executionData?.childWorkflowSnapshotId
+  const childWorkflowSnapshotState = childWorkflowSnapshotId
+    ? childWorkflowSnapshots?.[childWorkflowSnapshotId]
+    : undefined
 
   /** Drills down into the child workflow or opens it in a new tab */
   const handleExpandChildWorkflow = useCallback(() => {
-    if (!childWorkflowId || !childWorkflowState) return
+    if (!childWorkflowId) return
 
     if (isExecutionMode && onDrillDown) {
-      onDrillDown(block.id, childWorkflowState)
+      const resolvedChildState = childWorkflowSnapshotState ?? childWorkflowState
+      if (!resolvedChildState) return
+      onDrillDown(block.id, resolvedChildState)
     } else if (workspaceId) {
       window.open(`/workspace/${workspaceId}/w/${childWorkflowId}`, '_blank', 'noopener,noreferrer')
     }
-  }, [childWorkflowId, childWorkflowState, isExecutionMode, onDrillDown, block.id, workspaceId])
+  }, [
+    childWorkflowId,
+    childWorkflowSnapshotState,
+    childWorkflowState,
+    isExecutionMode,
+    onDrillDown,
+    block.id,
+    workspaceId,
+  ])
 
   const contentRef = useRef<HTMLDivElement>(null)
   const subBlocksRef = useRef<HTMLDivElement>(null)

apps/sim/app/workspace/[workspaceId]/w/components/preview/preview.tsx

@@ -19,6 +19,8 @@ interface TraceSpan {
   status?: string
   duration?: number
   children?: TraceSpan[]
+  childWorkflowSnapshotId?: string
+  childWorkflowId?: string
 }
 
 interface BlockExecutionData {
@@ -28,6 +30,7 @@ interface BlockExecutionData {
   durationMs: number
   /** Child trace spans for nested workflow blocks */
   children?: TraceSpan[]
+  childWorkflowSnapshotId?: string
 }
 
 /** Represents a level in the workflow navigation stack */
@@ -89,6 +92,7 @@ export function buildBlockExecutions(spans: TraceSpan[]): Record<string, BlockEx
         status: span.status || 'unknown',
         durationMs: span.duration || 0,
         children: span.children,
+        childWorkflowSnapshotId: span.childWorkflowSnapshotId,
       }
     }
   }
@@ -103,6 +107,8 @@ interface PreviewProps {
   traceSpans?: TraceSpan[]
   /** Pre-computed block executions (optional - will be built from traceSpans if not provided) */
   blockExecutions?: Record<string, BlockExecutionData>
+  /** Child workflow snapshots keyed by snapshot ID (execution mode only) */
+  childWorkflowSnapshots?: Record<string, WorkflowState>
   /** Additional CSS class names */
   className?: string
   /** Height of the component */
@@ -135,6 +141,7 @@ export function Preview({
   workflowState: rootWorkflowState,
   traceSpans: rootTraceSpans,
   blockExecutions: providedBlockExecutions,
+  childWorkflowSnapshots,
   className,
   height = '100%',
   width = '100%',
@@ -284,6 +291,7 @@ export function Preview({
           loops={workflowState.loops}
           parallels={workflowState.parallels}
           isExecutionMode={isExecutionMode}
+          childWorkflowSnapshots={childWorkflowSnapshots}
           onClose={handleEditorClose}
           onDrillDown={handleDrillDown}
         />

apps/sim/executor/errors/child-workflow-error.ts

@@ -6,6 +6,7 @@ interface ChildWorkflowErrorOptions {
   childWorkflowName: string
   childTraceSpans?: TraceSpan[]
   executionResult?: ExecutionResult
+  childWorkflowSnapshotId?: string
   cause?: Error
 }
 
@@ -16,6 +17,7 @@ export class ChildWorkflowError extends Error {
   readonly childTraceSpans: TraceSpan[]
   readonly childWorkflowName: string
   readonly executionResult?: ExecutionResult
+  readonly childWorkflowSnapshotId?: string
 
   constructor(options: ChildWorkflowErrorOptions) {
     super(options.message, { cause: options.cause })
@@ -23,6 +25,7 @@ export class ChildWorkflowError extends Error {
     this.childWorkflowName = options.childWorkflowName
     this.childTraceSpans = options.childTraceSpans ?? []
     this.executionResult = options.executionResult
+    this.childWorkflowSnapshotId = options.childWorkflowSnapshotId
   }
 
   static isChildWorkflowError(error: unknown): error is ChildWorkflowError {

apps/sim/executor/execution/block-executor.ts

@@ -237,6 +237,9 @@ export class BlockExecutor {
     if (ChildWorkflowError.isChildWorkflowError(error)) {
       errorOutput.childTraceSpans = error.childTraceSpans
       errorOutput.childWorkflowName = error.childWorkflowName
+      if (error.childWorkflowSnapshotId) {
+        errorOutput.childWorkflowSnapshotId = error.childWorkflowSnapshotId
+      }
     }
 
     this.state.setBlockOutput(node.id, errorOutput, duration)

apps/sim/executor/handlers/workflow/workflow-handler.ts

@@ -1,4 +1,5 @@
 import { createLogger } from '@sim/logger'
+import { snapshotService } from '@/lib/logs/execution/snapshot/service'
 import { buildTraceSpans } from '@/lib/logs/execution/trace-spans/trace-spans'
 import type { TraceSpan } from '@/lib/logs/types'
 import type { BlockOutput } from '@/blocks/types'
@@ -57,6 +58,7 @@ export class WorkflowBlockHandler implements BlockHandler {
     const workflowMetadata = workflows[workflowId]
     let childWorkflowName = workflowMetadata?.name || workflowId
 
+    let childWorkflowSnapshotId: string | undefined
     try {
       const currentDepth = (ctx.workflowId?.split('_sub_').length || 1) - 1
       if (currentDepth >= DEFAULTS.MAX_WORKFLOW_DEPTH) {
@@ -107,6 +109,12 @@ export class WorkflowBlockHandler implements BlockHandler {
         childWorkflowInput = inputs.input
       }
 
+      const childSnapshotResult = await snapshotService.createSnapshotWithDeduplication(
+        workflowId,
+        childWorkflow.workflowState
+      )
+      childWorkflowSnapshotId = childSnapshotResult.snapshot.id
+
       const subExecutor = new Executor({
         workflow: childWorkflow.serializedState,
         workflowInput: childWorkflowInput,
@@ -139,7 +147,8 @@ export class WorkflowBlockHandler implements BlockHandler {
         workflowId,
         childWorkflowName,
         duration,
-        childTraceSpans
+        childTraceSpans,
+        childWorkflowSnapshotId
       )
 
       return mappedResult
@@ -172,6 +181,7 @@ export class WorkflowBlockHandler implements BlockHandler {
         childWorkflowName,
         childTraceSpans,
         executionResult,
+        childWorkflowSnapshotId,
         cause: error instanceof Error ? error : undefined,
       })
     }
@@ -279,6 +289,10 @@ export class WorkflowBlockHandler implements BlockHandler {
     )
 
     const workflowVariables = (workflowData.variables as Record<string, any>) || {}
+    const workflowStateWithVariables = {
+      ...workflowState,
+      variables: workflowVariables,
+    }
 
     if (Object.keys(workflowVariables).length > 0) {
       logger.info(
@@ -290,6 +304,7 @@ export class WorkflowBlockHandler implements BlockHandler {
       name: workflowData.name,
       serializedState: serializedWorkflow,
       variables: workflowVariables,
+      workflowState: workflowStateWithVariables,
       rawBlocks: workflowState.blocks,
     }
   }
@@ -358,11 +373,16 @@ export class WorkflowBlockHandler implements BlockHandler {
     )
 
     const workflowVariables = (wfData?.variables as Record<string, any>) || {}
+    const workflowStateWithVariables = {
+      ...deployedState,
+      variables: workflowVariables,
+    }
 
     return {
       name: wfData?.name || DEFAULTS.WORKFLOW_NAME,
       serializedState: serializedWorkflow,
       variables: workflowVariables,
+      workflowState: workflowStateWithVariables,
       rawBlocks: deployedState.blocks,
     }
   }
@@ -504,7 +524,8 @@ export class WorkflowBlockHandler implements BlockHandler {
     childWorkflowId: string,
     childWorkflowName: string,
     duration: number,
-    childTraceSpans?: WorkflowTraceSpan[]
+    childTraceSpans?: WorkflowTraceSpan[],
+    childWorkflowSnapshotId?: string
   ): BlockOutput {
     const success = childResult.success !== false
     const result = childResult.output || {}
@@ -521,6 +542,8 @@ export class WorkflowBlockHandler implements BlockHandler {
     return {
       success: true,
       childWorkflowName,
+      childWorkflowId,
+      childWorkflowSnapshotId,
       result,
       childTraceSpans: childTraceSpans || [],
     } as Record<string, any>

apps/sim/hooks/queries/logs.ts

@@ -210,6 +210,7 @@ export interface ExecutionSnapshotData {
   executionId: string
   workflowId: string
   workflowState: Record<string, unknown>
+  childWorkflowSnapshots?: Record<string, Record<string, unknown>>
   executionMetadata: {
     trigger: string
     startedAt: string

apps/sim/lib/logs/execution/trace-spans/trace-spans.ts

@@ -112,6 +112,26 @@ export function buildTraceSpans(result: ExecutionResult): {
     const duration = log.durationMs || 0
 
     let output = log.output || {}
+    let childWorkflowSnapshotId: string | undefined
+    let childWorkflowId: string | undefined
+
+    if (output && typeof output === 'object') {
+      const outputRecord = output as Record<string, unknown>
+      childWorkflowSnapshotId =
+        typeof outputRecord.childWorkflowSnapshotId === 'string'
+          ? outputRecord.childWorkflowSnapshotId
+          : undefined
+      childWorkflowId =
+        typeof outputRecord.childWorkflowId === 'string' ? outputRecord.childWorkflowId : undefined
+      if (childWorkflowSnapshotId || childWorkflowId) {
+        const {
+          childWorkflowSnapshotId: _childSnapshotId,
+          childWorkflowId: _childWorkflowId,
+          ...outputRest
+        } = outputRecord
+        output = outputRest
+      }
+    }
 
     if (log.error) {
       output = {
@@ -134,6 +154,8 @@ export function buildTraceSpans(result: ExecutionResult): {
       blockId: log.blockId,
       input: log.input || {},
       output: output,
+      ...(childWorkflowSnapshotId ? { childWorkflowSnapshotId } : {}),
+      ...(childWorkflowId ? { childWorkflowId } : {}),
       ...(log.loopId && { loopId: log.loopId }),
       ...(log.parallelId && { parallelId: log.parallelId }),
       ...(log.iterationIndex !== undefined && { iterationIndex: log.iterationIndex }),

apps/sim/lib/logs/types.ts

@@ -178,6 +178,8 @@ export interface TraceSpan {
   blockId?: string
   input?: Record<string, unknown>
   output?: Record<string, unknown>
+  childWorkflowSnapshotId?: string
+  childWorkflowId?: string
   model?: string
   cost?: {
     input?: number