chore(utils): replace deepClone wrapper with structuredClone built-in

deepClone() was a one-line wrapper around structuredClone(), which is
universally available in Node 17+ and all modern browsers. Removing the
abstraction reduces indirection and means contributors don't need to
learn a project-specific name for a well-known built-in.

- Remove deepClone from packages/utils/src/object.ts and index.ts
- Replace all 17 call sites with structuredClone() directly
- Update check:utils script suggestion text
- Update CLAUDE.md and global.md docs

Author: waleedlatif1

.claude/rules/global.md

@@ -39,7 +39,7 @@ Use shared helpers from `@sim/utils` instead of writing inline implementations:
 - `sleep(ms)` from `@sim/utils/helpers` — async delay. Never write `new Promise(resolve => setTimeout(resolve, ms))`
 - `toError(value)` from `@sim/utils/errors` — normalize unknown caught values to `Error`. Never write `e instanceof Error ? e : new Error(String(e))`
 - `getErrorMessage(value, fallback?)` from `@sim/utils/errors` — extract error message string. Never write `e instanceof Error ? e.message : 'fallback'`
-- `deepClone(value)` from `@sim/utils/object` — structural clone. Never write `JSON.parse(JSON.stringify(obj))`
+- `structuredClone(value)` — built-in deep clone, no import needed. Never write `JSON.parse(JSON.stringify(obj))`
 - `omit(obj, keys)` from `@sim/utils/object` — remove keys from object
 - `filterUndefined(obj)` from `@sim/utils/object` — strip undefined-valued keys. Never write `Object.fromEntries(Object.entries(obj).filter(([, v]) => v !== undefined))`
 - `truncate(str, maxLength, suffix?)` from `@sim/utils/string` — safe string truncation with ellipsis
@@ -56,10 +56,10 @@ const filtered = Object.fromEntries(Object.entries(obj).filter(([, v]) => v !==
 // ✓ Good
 import { sleep } from '@sim/utils/helpers'
 import { getErrorMessage, toError } from '@sim/utils/errors'
-import { deepClone, filterUndefined } from '@sim/utils/object'
+import { filterUndefined } from '@sim/utils/object'
 await sleep(1000)
 const msg = getErrorMessage(error, 'Unknown error')
-const clone = deepClone(obj)
+const clone = structuredClone(obj)
 const filtered = filterUndefined(obj)
 ```
 

CLAUDE.md

@@ -14,7 +14,7 @@ You are a professional software engineer. All code must follow best practices: a
   - `sleep(ms)` from `@sim/utils/helpers` — never `new Promise(resolve => setTimeout(resolve, ms))`
   - `toError(e)` from `@sim/utils/errors` — normalize caught values to `Error`
   - `getErrorMessage(e, fallback?)` from `@sim/utils/errors` — extract message string from unknown caught value; never write `e instanceof Error ? e.message : 'fallback'`
-  - `deepClone(value)` from `@sim/utils/object` — structural clone; never `JSON.parse(JSON.stringify(...))`
+  - `structuredClone(value)` — built-in deep clone; never `JSON.parse(JSON.stringify(...))`
   - `omit(obj, keys)` / `filterUndefined(obj)` from `@sim/utils/object` — object trimming; never `Object.fromEntries(Object.entries(...).filter(...))`
   - `truncate(str, maxLength, suffix?)` from `@sim/utils/string` — never inline slice + ellipsis
   - `backoffWithJitter(attempt, retryAfterMs, options?)` / `parseRetryAfter(header)` from `@sim/utils/retry` — shared retry pacing; never reimplement exponential backoff inline

apps/sim/app/resume/[workflowId]/[executionId]/page.tsx

@@ -1,4 +1,3 @@
-import { deepClone } from '@sim/utils/object'
 import type { Metadata } from 'next'
 import { PauseResumeManager } from '@/lib/workflows/executor/human-in-the-loop-manager'
 import ResumeExecutionPage from '@/app/resume/[workflowId]/[executionId]/resume-page-client'
@@ -40,7 +39,7 @@ export default async function ResumeExecutionPageWrapper({
   return (
     <ResumeExecutionPage
       params={resolvedParams}
-      initialExecutionDetail={detail ? deepClone(detail) : null}
+      initialExecutionDetail={detail ? structuredClone(detail) : null}
       initialContextId={initialContextId}
     />
   )

apps/sim/app/workspace/[workspaceId]/settings/components/mcp/components/mcp-server-form-modal/mcp-server-form-modal.tsx

@@ -3,7 +3,6 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import { createLogger } from '@sim/logger'
 import { getErrorMessage } from '@sim/utils/errors'
-import { deepClone } from '@sim/utils/object'
 import {
   Button,
   Input as EmcnInput,
@@ -329,7 +328,7 @@ export function McpServerFormModal({
   if (open && !prevOpen) {
     const data = initialData ?? DEFAULT_FORM_DATA
     setFormData(data)
-    setOriginalData(deepClone(data))
+    setOriginalData(structuredClone(data))
     setFormMode('form')
     setJsonInput('')
     setJsonError(null)

apps/sim/app/workspace/[workspaceId]/settings/components/secrets/secrets-manager.tsx

@@ -4,7 +4,6 @@ import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import { createLogger } from '@sim/logger'
 import { getErrorMessage } from '@sim/utils/errors'
 import { generateShortId } from '@sim/utils/id'
-import { deepClone } from '@sim/utils/object'
 import { useQueryClient } from '@tanstack/react-query'
 import { Check, Clipboard, Key, Search } from 'lucide-react'
 import { useParams, useRouter } from 'next/navigation'
@@ -599,8 +598,8 @@ export function SecretsManager() {
       })),
       createEmptyEnvVar(),
     ]
-    initialVarsRef.current = deepClone(initialVars)
-    setEnvVars(deepClone(initialVars))
+    initialVarsRef.current = structuredClone(initialVars)
+    setEnvVars(structuredClone(initialVars))
   }, [personalEnvData])
 
   useEffect(() => {
@@ -957,7 +956,7 @@ export function SecretsManager() {
   }
 
   const resetToSaved = () => {
-    setEnvVars(deepClone(initialVarsRef.current))
+    setEnvVars(structuredClone(initialVarsRef.current))
     setWorkspaceVars({ ...initialWorkspaceVarsRef.current })
     setNewWorkspaceRows([createEmptyEnvVar()])
     setShowUnsavedChanges(false)
@@ -1038,7 +1037,7 @@ export function SecretsManager() {
       if (firstFailure) throw firstFailure.reason
 
       initialWorkspaceVarsRef.current = { ...mergedWorkspaceVars }
-      initialVarsRef.current = deepClone(envVars.filter((v) => v.key && v.value))
+      initialVarsRef.current = structuredClone(envVars.filter((v) => v.key && v.value))
 
       setWorkspaceVars(mergedWorkspaceVars)
       setNewWorkspaceRows([createEmptyEnvVar()])

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/hooks/use-sub-block-value.ts

@@ -1,6 +1,5 @@
 import { useCallback, useEffect, useRef } from 'react'
 import { createLogger } from '@sim/logger'
-import { deepClone } from '@sim/utils/object'
 import { isEqual } from 'es-toolkit'
 import { useShallow } from 'zustand/react/shallow'
 import { useStoreWithEqualityFn } from 'zustand/traditional'
@@ -150,7 +149,11 @@ export function useSubBlockValue<T = any>(
 
         // Ensure we're passing the actual value, not a reference that might change
         const valueCopy =
-          newValue === null ? null : typeof newValue === 'object' ? deepClone(newValue) : newValue
+          newValue === null
+            ? null
+            : typeof newValue === 'object'
+              ? structuredClone(newValue)
+              : newValue
 
         // If streaming, hold value locally and do not update global store to avoid render-phase updates
         if (isStreaming) {

apps/sim/lib/copilot/tools/server/workflow/edit-workflow/engine.ts

@@ -1,5 +1,4 @@
 import { createLogger } from '@sim/logger'
-import { deepClone } from '@sim/utils/object'
 import type { PermissionGroupConfig } from '@/lib/permission-groups/types'
 import { isValidKey } from '@/lib/workflows/sanitization/key-validation'
 import { validateEdges } from '@/stores/workflows/workflow/edge-validation'
@@ -153,7 +152,7 @@ export function applyOperationsToWorkflowState(
   permissionConfig: PermissionGroupConfig | null = null
 ): ApplyOperationsResult {
   // Deep clone the workflow state to avoid mutations
-  const modifiedState = deepClone(workflowState)
+  const modifiedState = structuredClone(workflowState)
 
   // Collect validation errors across all operations
   const validationErrors: ValidationError[] = []

apps/sim/lib/core/security/csp.test.ts

@@ -1,5 +1,4 @@
 import { createEnvMock, featureFlagsMock } from '@sim/testing'
-import { deepClone } from '@sim/utils/object'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 
 vi.mock('@/lib/core/config/env', () =>
@@ -186,7 +185,7 @@ describe('generateRuntimeCSP', () => {
 })
 
 describe('addCSPSource', () => {
-  const originalDirectives = deepClone(buildTimeCSPDirectives)
+  const originalDirectives = structuredClone(buildTimeCSPDirectives)
 
   afterEach(() => {
     Object.keys(buildTimeCSPDirectives).forEach((key) => {
@@ -223,7 +222,7 @@ describe('addCSPSource', () => {
 })
 
 describe('removeCSPSource', () => {
-  const originalDirectives = deepClone(buildTimeCSPDirectives)
+  const originalDirectives = structuredClone(buildTimeCSPDirectives)
 
   afterEach(() => {
     Object.keys(buildTimeCSPDirectives).forEach((key) => {

apps/sim/lib/core/security/redaction.test.ts

@@ -1,4 +1,3 @@
-import { deepClone } from '@sim/utils/object'
 import { describe, expect, it } from 'vitest'
 import {
   isLargeDataKey,
@@ -538,7 +537,7 @@ describe('Security edge cases', () => {
         },
       }
 
-      const originalCopy = deepClone(original)
+      const originalCopy = structuredClone(original)
       redactApiKeys(original)
 
       expect(original).toEqual(originalCopy)

apps/sim/lib/workflows/autolayout/index.ts

@@ -1,6 +1,5 @@
 import { createLogger } from '@sim/logger'
 import { getErrorMessage } from '@sim/utils/errors'
-import { deepClone } from '@sim/utils/object'
 import {
   DEFAULT_HORIZONTAL_SPACING,
   DEFAULT_VERTICAL_SPACING,
@@ -33,7 +32,7 @@ export function applyAutoLayout(
       edgeCount: edges.length,
     })
 
-    const blocksCopy: Record<string, BlockState> = deepClone(blocks)
+    const blocksCopy: Record<string, BlockState> = structuredClone(blocks)
 
     const horizontalSpacing = options.horizontalSpacing ?? DEFAULT_HORIZONTAL_SPACING
     const verticalSpacing = options.verticalSpacing ?? DEFAULT_VERTICAL_SPACING