refactor(workflow): use pre-computed lock state from contextMenuBlocks

contextMenuBlocks already has locked and isParentLocked properties
computed in use-canvas-context-menu.ts, so there's no need to look
up blocks again via hasProtectedBlocks.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/docs/content/docs/en/quick-reference/index.mdx

@@ -180,6 +180,11 @@ A quick lookup for everyday actions in the Sim workflow editor. For keyboard sho
       <td>Right-click → **Enable/Disable**</td>
       <td><ActionImage src="/static/quick-reference/disable-block.png" alt="Disable block" /></td>
     </tr>
+    <tr>
+      <td>Lock/Unlock a block</td>
+      <td>Hover block → Click lock icon (Admin only)</td>
+      <td><ActionImage src="/static/quick-reference/lock-block.png" alt="Lock block" /></td>
+    </tr>
     <tr>
       <td>Toggle handle orientation</td>
       <td>Right-click → **Toggle Handles**</td>

apps/docs/content/docs/en/tools/pulse.mdx

@@ -11,7 +11,7 @@ import { BlockInfoCard } from "@/components/ui/block-info-card"
 />
 
 {/* MANUAL-CONTENT-START:intro */}
-The [Pulse](https://www.pulseapi.com/) tool enables seamless extraction of text and structured content from a wide variety of documents—including PDFs, images, and Office files—using state-of-the-art OCR (Optical Character Recognition) powered by Pulse. Designed for automated agentic workflows, Pulse Parser makes it easy to unlock valuable information trapped in unstructured documents and integrate the extracted content directly into your workflow.
+The [Pulse](https://www.runpulse.com) tool enables seamless extraction of text and structured content from a wide variety of documents—including PDFs, images, and Office files—using state-of-the-art OCR (Optical Character Recognition) powered by Pulse. Designed for automated agentic workflows, Pulse Parser makes it easy to unlock valuable information trapped in unstructured documents and integrate the extracted content directly into your workflow.
 
 With Pulse, you can:
 

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/action-bar/action-bar.tsx

@@ -1,5 +1,5 @@
 import { memo, useCallback } from 'react'
-import { ArrowLeftRight, ArrowUpDown, Circle, CircleOff, LogOut } from 'lucide-react'
+import { ArrowLeftRight, ArrowUpDown, Circle, CircleOff, Lock, LogOut, Unlock } from 'lucide-react'
 import { Button, Copy, PlayOutline, Tooltip, Trash2 } from '@/components/emcn'
 import { cn } from '@/lib/core/utils/cn'
 import { isInputDefinitionTrigger } from '@/lib/workflows/triggers/input-definition-triggers'
@@ -49,6 +49,7 @@ export const ActionBar = memo(
       collaborativeBatchRemoveBlocks,
       collaborativeBatchToggleBlockEnabled,
       collaborativeBatchToggleBlockHandles,
+      collaborativeBatchToggleLocked,
     } = useCollaborativeWorkflow()
     const { setPendingSelection } = useWorkflowRegistry()
     const { handleRunFromBlock } = useWorkflowExecution()
@@ -84,16 +85,28 @@ export const ActionBar = memo(
       )
     }, [blockId, addNotification, collaborativeBatchAddBlocks, setPendingSelection])
 
-    const { isEnabled, horizontalHandles, parentId, parentType } = useWorkflowStore(
+    const {
+      isEnabled,
+      horizontalHandles,
+      parentId,
+      parentType,
+      isLocked,
+      isParentLocked,
+      isParentDisabled,
+    } = useWorkflowStore(
       useCallback(
         (state) => {
           const block = state.blocks[blockId]
           const parentId = block?.data?.parentId
+          const parentBlock = parentId ? state.blocks[parentId] : undefined
           return {
             isEnabled: block?.enabled ?? true,
             horizontalHandles: block?.horizontalHandles ?? false,
             parentId,
-            parentType: parentId ? state.blocks[parentId]?.type : undefined,
+            parentType: parentBlock?.type,
+            isLocked: block?.locked ?? false,
+            isParentLocked: parentBlock?.locked ?? false,
+            isParentDisabled: parentBlock ? !parentBlock.enabled : false,
           }
         },
         [blockId]
@@ -161,25 +174,27 @@ export const ActionBar = memo(
         {!isNoteBlock && !isInsideSubflow && (
           <Tooltip.Root>
             <Tooltip.Trigger asChild>
-              <Button
-                variant='ghost'
-                onClick={(e) => {
-                  e.stopPropagation()
-                  if (canRunFromBlock && !disabled) {
-                    handleRunFromBlockClick()
-                  }
-                }}
-                className={ACTION_BUTTON_STYLES}
-                disabled={disabled || !canRunFromBlock}
-              >
-                <PlayOutline className={ICON_SIZE} />
-              </Button>
+              <span className='inline-flex'>
+                <Button
+                  variant='ghost'
+                  onClick={(e) => {
+                    e.stopPropagation()
+                    if (canRunFromBlock && !disabled) {
+                      handleRunFromBlockClick()
+                    }
+                  }}
+                  className={ACTION_BUTTON_STYLES}
+                  disabled={disabled || !canRunFromBlock}
+                >
+                  <PlayOutline className={ICON_SIZE} />
+                </Button>
+              </span>
             </Tooltip.Trigger>
             <Tooltip.Content side='top'>
               {(() => {
                 if (disabled) return getTooltipMessage('Run from block')
                 if (isExecuting) return 'Execution in progress'
-                if (!dependenciesSatisfied) return 'Run upstream blocks first'
+                if (!dependenciesSatisfied) return 'Run previous blocks first'
                 return 'Run from block'
               })()}
             </Tooltip.Content>
@@ -193,18 +208,54 @@ export const ActionBar = memo(
                 variant='ghost'
                 onClick={(e) => {
                   e.stopPropagation()
-                  if (!disabled) {
+                  // Can't enable if parent is disabled (must enable parent first)
+                  const cantEnable = !isEnabled && isParentDisabled
+                  if (!disabled && !isLocked && !isParentLocked && !cantEnable) {
                     collaborativeBatchToggleBlockEnabled([blockId])
                   }
                 }}
                 className={ACTION_BUTTON_STYLES}
-                disabled={disabled}
+                disabled={
+                  disabled || isLocked || isParentLocked || (!isEnabled && isParentDisabled)
+                }
               >
                 {isEnabled ? <Circle className={ICON_SIZE} /> : <CircleOff className={ICON_SIZE} />}
               </Button>
             </Tooltip.Trigger>
             <Tooltip.Content side='top'>
-              {getTooltipMessage(isEnabled ? 'Disable Block' : 'Enable Block')}
+              {isLocked || isParentLocked
+                ? 'Block is locked'
+                : !isEnabled && isParentDisabled
+                  ? 'Parent container is disabled'
+                  : getTooltipMessage(isEnabled ? 'Disable Block' : 'Enable Block')}
+            </Tooltip.Content>
+          </Tooltip.Root>
+        )}
+
+        {userPermissions.canAdmin && (
+          <Tooltip.Root>
+            <Tooltip.Trigger asChild>
+              <Button
+                variant='ghost'
+                onClick={(e) => {
+                  e.stopPropagation()
+                  // Can't unlock a block if its parent container is locked
+                  if (!disabled && !(isLocked && isParentLocked)) {
+                    collaborativeBatchToggleLocked([blockId])
+                  }
+                }}
+                className={ACTION_BUTTON_STYLES}
+                disabled={disabled || (isLocked && isParentLocked)}
+              >
+                {isLocked ? <Unlock className={ICON_SIZE} /> : <Lock className={ICON_SIZE} />}
+              </Button>
+            </Tooltip.Trigger>
+            <Tooltip.Content side='top'>
+              {isLocked && isParentLocked
+                ? 'Parent container is locked'
+                : isLocked
+                  ? 'Unlock Block'
+                  : 'Lock Block'}
             </Tooltip.Content>
           </Tooltip.Root>
         )}
@@ -237,12 +288,12 @@ export const ActionBar = memo(
                 variant='ghost'
                 onClick={(e) => {
                   e.stopPropagation()
-                  if (!disabled) {
+                  if (!disabled && !isLocked && !isParentLocked) {
                     collaborativeBatchToggleBlockHandles([blockId])
                   }
                 }}
                 className={ACTION_BUTTON_STYLES}
-                disabled={disabled}
+                disabled={disabled || isLocked || isParentLocked}
               >
                 {horizontalHandles ? (
                   <ArrowLeftRight className={ICON_SIZE} />
@@ -252,7 +303,9 @@ export const ActionBar = memo(
               </Button>
             </Tooltip.Trigger>
             <Tooltip.Content side='top'>
-              {getTooltipMessage(horizontalHandles ? 'Vertical Ports' : 'Horizontal Ports')}
+              {isLocked || isParentLocked
+                ? 'Block is locked'
+                : getTooltipMessage(horizontalHandles ? 'Vertical Ports' : 'Horizontal Ports')}
             </Tooltip.Content>
           </Tooltip.Root>
         )}
@@ -264,19 +317,23 @@ export const ActionBar = memo(
                 variant='ghost'
                 onClick={(e) => {
                   e.stopPropagation()
-                  if (!disabled && userPermissions.canEdit) {
+                  if (!disabled && userPermissions.canEdit && !isLocked && !isParentLocked) {
                     window.dispatchEvent(
                       new CustomEvent('remove-from-subflow', { detail: { blockIds: [blockId] } })
                     )
                   }
                 }}
                 className={ACTION_BUTTON_STYLES}
-                disabled={disabled || !userPermissions.canEdit}
+                disabled={disabled || !userPermissions.canEdit || isLocked || isParentLocked}
               >
                 <LogOut className={ICON_SIZE} />
               </Button>
             </Tooltip.Trigger>
-            <Tooltip.Content side='top'>{getTooltipMessage('Remove from Subflow')}</Tooltip.Content>
+            <Tooltip.Content side='top'>
+              {isLocked || isParentLocked
+                ? 'Block is locked'
+                : getTooltipMessage('Remove from Subflow')}
+            </Tooltip.Content>
           </Tooltip.Root>
         )}
 
@@ -286,17 +343,19 @@ export const ActionBar = memo(
               variant='ghost'
               onClick={(e) => {
                 e.stopPropagation()
-                if (!disabled) {
+                if (!disabled && !isLocked && !isParentLocked) {
                   collaborativeBatchRemoveBlocks([blockId])
                 }
               }}
               className={ACTION_BUTTON_STYLES}
-              disabled={disabled}
+              disabled={disabled || isLocked || isParentLocked}
             >
               <Trash2 className={ICON_SIZE} />
             </Button>
           </Tooltip.Trigger>
-          <Tooltip.Content side='top'>{getTooltipMessage('Delete Block')}</Tooltip.Content>
+          <Tooltip.Content side='top'>
+            {isLocked || isParentLocked ? 'Block is locked' : getTooltipMessage('Delete Block')}
+          </Tooltip.Content>
         </Tooltip.Root>
       </div>
     )

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/block-menu/block-menu.tsx

@@ -20,6 +20,9 @@ export interface BlockInfo {
   horizontalHandles: boolean
   parentId?: string
   parentType?: string
+  locked?: boolean
+  isParentLocked?: boolean
+  isParentDisabled?: boolean
 }
 
 /**
@@ -46,10 +49,17 @@ export interface BlockMenuProps {
   showRemoveFromSubflow?: boolean
   /** Whether run from block is available (has snapshot, was executed, not inside subflow) */
   canRunFromBlock?: boolean
+  /** Whether to disable edit actions (user can't edit OR blocks are locked) */
   disableEdit?: boolean
+  /** Whether the user has edit permission (ignoring locked state) */
+  userCanEdit?: boolean
   isExecuting?: boolean
   /** Whether the selected block is a trigger (has no incoming edges) */
   isPositionalTrigger?: boolean
+  /** Callback to toggle locked state of selected blocks */
+  onToggleLocked?: () => void
+  /** Whether the user has admin permissions */
+  canAdmin?: boolean
 }
 
 /**
@@ -78,13 +88,22 @@ export function BlockMenu({
   showRemoveFromSubflow = false,
   canRunFromBlock = false,
   disableEdit = false,
+  userCanEdit = true,
   isExecuting = false,
   isPositionalTrigger = false,
+  onToggleLocked,
+  canAdmin = false,
 }: BlockMenuProps) {
   const isSingleBlock = selectedBlocks.length === 1
 
   const allEnabled = selectedBlocks.every((b) => b.enabled)
   const allDisabled = selectedBlocks.every((b) => !b.enabled)
+  const allLocked = selectedBlocks.every((b) => b.locked)
+  const allUnlocked = selectedBlocks.every((b) => !b.locked)
+  // Can't unlock blocks that have locked parents
+  const hasBlockWithLockedParent = selectedBlocks.some((b) => b.locked && b.isParentLocked)
+  // Can't enable blocks that have disabled parents
+  const hasBlockWithDisabledParent = selectedBlocks.some((b) => !b.enabled && b.isParentDisabled)
 
   const hasSingletonBlock = selectedBlocks.some(
     (b) =>
@@ -108,6 +127,12 @@ export function BlockMenu({
     return 'Toggle Enabled'
   }
 
+  const getToggleLockedLabel = () => {
+    if (allLocked) return 'Unlock'
+    if (allUnlocked) return 'Lock'
+    return 'Toggle Lock'
+  }
+
   return (
     <Popover
       open={isOpen}
@@ -139,7 +164,7 @@ export function BlockMenu({
         </PopoverItem>
         <PopoverItem
           className='group'
-          disabled={disableEdit || !hasClipboard}
+          disabled={!userCanEdit || !hasClipboard}
           onClick={() => {
             onPaste()
             onClose()
@@ -150,7 +175,7 @@ export function BlockMenu({
         </PopoverItem>
         {!hasSingletonBlock && (
           <PopoverItem
-            disabled={disableEdit}
+            disabled={!userCanEdit}
             onClick={() => {
               onDuplicate()
               onClose()
@@ -164,13 +189,15 @@ export function BlockMenu({
         {!allNoteBlocks && <PopoverDivider />}
         {!allNoteBlocks && (
           <PopoverItem
-            disabled={disableEdit}
+            disabled={disableEdit || hasBlockWithDisabledParent}
             onClick={() => {
-              onToggleEnabled()
-              onClose()
+              if (!disableEdit && !hasBlockWithDisabledParent) {
+                onToggleEnabled()
+                onClose()
+              }
             }}
           >
-            {getToggleEnabledLabel()}
+            {hasBlockWithDisabledParent ? 'Parent is disabled' : getToggleEnabledLabel()}
           </PopoverItem>
         )}
         {!allNoteBlocks && !isSubflow && (
@@ -195,6 +222,19 @@ export function BlockMenu({
             Remove from Subflow
           </PopoverItem>
         )}
+        {canAdmin && onToggleLocked && (
+          <PopoverItem
+            disabled={hasBlockWithLockedParent}
+            onClick={() => {
+              if (!hasBlockWithLockedParent) {
+                onToggleLocked()
+                onClose()
+              }
+            }}
+          >
+            {hasBlockWithLockedParent ? 'Parent is locked' : getToggleLockedLabel()}
+          </PopoverItem>
+        )}
 
         {/* Single block actions */}
         {isSingleBlock && <PopoverDivider />}

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/canvas-menu/canvas-menu.tsx

@@ -34,6 +34,8 @@ export interface CanvasMenuProps {
   canUndo?: boolean
   canRedo?: boolean
   isInvitationsDisabled?: boolean
+  /** Whether the workflow has locked blocks (disables auto-layout) */
+  hasLockedBlocks?: boolean
 }
 
 /**
@@ -60,6 +62,7 @@ export function CanvasMenu({
   disableEdit = false,
   canUndo = false,
   canRedo = false,
+  hasLockedBlocks = false,
 }: CanvasMenuProps) {
   return (
     <Popover
@@ -129,11 +132,12 @@ export function CanvasMenu({
         </PopoverItem>
         <PopoverItem
           className='group'
-          disabled={disableEdit}
+          disabled={disableEdit || hasLockedBlocks}
           onClick={() => {
             onAutoLayout()
             onClose()
           }}
+          title={hasLockedBlocks ? 'Unlock blocks to use auto-layout' : undefined}
         >
           <span>Auto-layout</span>
           <span className='ml-auto opacity-70 group-hover:opacity-100'>⇧L</span>

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/editor.tsx

@@ -9,7 +9,9 @@ import {
   ChevronUp,
   ExternalLink,
   Loader2,
+  Lock,
   Pencil,
+  Unlock,
 } from 'lucide-react'
 import { useParams } from 'next/navigation'
 import { useShallow } from 'zustand/react/shallow'
@@ -46,6 +48,7 @@ import { useCollaborativeWorkflow } from '@/hooks/use-collaborative-workflow'
 import { usePanelEditorStore } from '@/stores/panel'
 import { useWorkflowRegistry } from '@/stores/workflows/registry/store'
 import { useSubBlockStore } from '@/stores/workflows/subblock/store'
+import { useWorkflowStore } from '@/stores/workflows/workflow/store'
 
 /** Stable empty object to avoid creating new references */
 const EMPTY_SUBBLOCK_VALUES = {} as Record<string, any>
@@ -110,6 +113,14 @@ export function Editor() {
   // Get user permissions
   const userPermissions = useUserPermissionsContext()
 
+  // Check if block is locked (or inside a locked container) and compute edit permission
+  // Locked blocks cannot be edited by anyone (admins can only lock/unlock)
+  const blocks = useWorkflowStore((state) => state.blocks)
+  const parentId = currentBlock?.data?.parentId as string | undefined
+  const isParentLocked = parentId ? (blocks[parentId]?.locked ?? false) : false
+  const isLocked = (currentBlock?.locked ?? false) || isParentLocked
+  const canEditBlock = userPermissions.canEdit && !isLocked
+
   // Get active workflow ID
   const activeWorkflowId = useWorkflowRegistry((state) => state.activeWorkflowId)
 
@@ -150,9 +161,7 @@ export function Editor() {
     blockSubBlockValues,
     canonicalIndex
   )
-  const displayAdvancedOptions = userPermissions.canEdit
-    ? advancedMode
-    : advancedMode || advancedValuesPresent
+  const displayAdvancedOptions = canEditBlock ? advancedMode : advancedMode || advancedValuesPresent
 
   const hasAdvancedOnlyFields = useMemo(() => {
     for (const subBlock of subBlocksForCanonical) {
@@ -219,13 +228,14 @@ export function Editor() {
     collaborativeSetBlockCanonicalMode,
     collaborativeUpdateBlockName,
     collaborativeToggleBlockAdvancedMode,
+    collaborativeBatchToggleLocked,
   } = useCollaborativeWorkflow()
 
   // Advanced mode toggle handler
   const handleToggleAdvancedMode = useCallback(() => {
-    if (!currentBlockId || !userPermissions.canEdit) return
+    if (!currentBlockId || !canEditBlock) return
     collaborativeToggleBlockAdvancedMode(currentBlockId)
-  }, [currentBlockId, userPermissions.canEdit, collaborativeToggleBlockAdvancedMode])
+  }, [currentBlockId, canEditBlock, collaborativeToggleBlockAdvancedMode])
 
   // Rename state
   const [isRenaming, setIsRenaming] = useState(false)
@@ -236,10 +246,10 @@ export function Editor() {
    * Handles starting the rename process.
    */
   const handleStartRename = useCallback(() => {
-    if (!userPermissions.canEdit || !currentBlock) return
+    if (!canEditBlock || !currentBlock) return
     setEditedName(currentBlock.name || '')
     setIsRenaming(true)
-  }, [userPermissions.canEdit, currentBlock])
+  }, [canEditBlock, currentBlock])
 
   /**
    * Handles saving the renamed block.
@@ -358,6 +368,36 @@ export function Editor() {
           )}
         </div>
         <div className='flex shrink-0 items-center gap-[8px]'>
+          {/* Locked indicator - clickable to unlock if user has admin permissions, block is locked, and parent is not locked */}
+          {isLocked && currentBlock && (
+            <Tooltip.Root>
+              <Tooltip.Trigger asChild>
+                {userPermissions.canAdmin && currentBlock.locked && !isParentLocked ? (
+                  <Button
+                    variant='ghost'
+                    className='p-0'
+                    onClick={() => collaborativeBatchToggleLocked([currentBlockId!])}
+                    aria-label='Unlock block'
+                  >
+                    <Unlock className='h-[14px] w-[14px] text-[var(--text-secondary)]' />
+                  </Button>
+                ) : (
+                  <div className='flex items-center justify-center'>
+                    <Lock className='h-[14px] w-[14px] text-[var(--text-secondary)]' />
+                  </div>
+                )}
+              </Tooltip.Trigger>
+              <Tooltip.Content side='top'>
+                <p>
+                  {isParentLocked
+                    ? 'Parent container is locked'
+                    : userPermissions.canAdmin && currentBlock.locked
+                      ? 'Unlock block'
+                      : 'Block is locked'}
+                </p>
+              </Tooltip.Content>
+            </Tooltip.Root>
+          )}
           {/* Rename button */}
           {currentBlock && (
             <Tooltip.Root>
@@ -366,7 +406,7 @@ export function Editor() {
                   variant='ghost'
                   className='p-0'
                   onClick={isRenaming ? handleSaveRename : handleStartRename}
-                  disabled={!userPermissions.canEdit}
+                  disabled={!canEditBlock}
                   aria-label={isRenaming ? 'Save name' : 'Rename block'}
                 >
                   {isRenaming ? (
@@ -434,7 +474,7 @@ export function Editor() {
           incomingConnections={incomingConnections}
           handleConnectionsResizeMouseDown={handleConnectionsResizeMouseDown}
           toggleConnectionsCollapsed={toggleConnectionsCollapsed}
-          userCanEdit={userPermissions.canEdit}
+          userCanEdit={canEditBlock}
           isConnectionsAtMinHeight={isConnectionsAtMinHeight}
         />
       ) : (
@@ -542,14 +582,14 @@ export function Editor() {
                           config={subBlock}
                           isPreview={false}
                           subBlockValues={subBlockState}
-                          disabled={!userPermissions.canEdit}
+                          disabled={!canEditBlock}
                           fieldDiffStatus={undefined}
                           allowExpandInPreview={false}
                           canonicalToggle={
                             isCanonicalSwap && canonicalMode && canonicalId
                               ? {
                                   mode: canonicalMode,
-                                  disabled: !userPermissions.canEdit,
+                                  disabled: !canEditBlock,
                                   onToggle: () => {
                                     if (!currentBlockId) return
                                     const nextMode =
@@ -579,7 +619,7 @@ export function Editor() {
                     )
                   })}
 
-                  {hasAdvancedOnlyFields && userPermissions.canEdit && (
+                  {hasAdvancedOnlyFields && canEditBlock && (
                     <div className='flex items-center gap-[10px] px-[2px] pt-[14px] pb-[12px]'>
                       <div
                         className='h-[1.25px] flex-1'
@@ -624,7 +664,7 @@ export function Editor() {
                           config={subBlock}
                           isPreview={false}
                           subBlockValues={subBlockState}
-                          disabled={!userPermissions.canEdit}
+                          disabled={!canEditBlock}
                           fieldDiffStatus={undefined}
                           allowExpandInPreview={false}
                         />

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

@@ -45,11 +45,13 @@ import { useWorkflowExecution } from '@/app/workspace/[workspaceId]/w/[workflowI
 import { useDeleteWorkflow, useImportWorkflow } from '@/app/workspace/[workspaceId]/w/hooks'
 import { usePermissionConfig } from '@/hooks/use-permission-config'
 import { useChatStore } from '@/stores/chat/store'
+import { useNotificationStore } from '@/stores/notifications/store'
 import type { PanelTab } from '@/stores/panel'
 import { usePanelStore, useVariablesStore as usePanelVariablesStore } from '@/stores/panel'
 import { useVariablesStore } from '@/stores/variables/store'
 import { getWorkflowWithValues } from '@/stores/workflows'
 import { useWorkflowRegistry } from '@/stores/workflows/registry/store'
+import { useWorkflowStore } from '@/stores/workflows/workflow/store'
 
 const logger = createLogger('Panel')
 /**
@@ -119,6 +121,11 @@ export const Panel = memo(function Panel() {
     hydration.phase === 'state-loading'
   const { handleAutoLayout: autoLayoutWithFitView } = useAutoLayout(activeWorkflowId || null)
 
+  // Check for locked blocks (disables auto-layout)
+  const hasLockedBlocks = useWorkflowStore((state) =>
+    Object.values(state.blocks).some((block) => block.locked)
+  )
+
   // Delete workflow hook
   const { isDeleting, handleDeleteWorkflow } = useDeleteWorkflow({
     workspaceId,
@@ -230,11 +237,24 @@ export const Panel = memo(function Panel() {
 
     setIsAutoLayouting(true)
     try {
-      await autoLayoutWithFitView()
+      const result = await autoLayoutWithFitView()
+      if (!result.success && result.error) {
+        useNotificationStore.getState().addNotification({
+          level: 'info',
+          message: result.error,
+          workflowId: activeWorkflowId || undefined,
+        })
+      }
     } finally {
       setIsAutoLayouting(false)
     }
-  }, [isExecuting, userPermissions.canEdit, isAutoLayouting, autoLayoutWithFitView])
+  }, [
+    isExecuting,
+    userPermissions.canEdit,
+    isAutoLayouting,
+    autoLayoutWithFitView,
+    activeWorkflowId,
+  ])
 
   /**
    * Handles exporting workflow as JSON
@@ -404,7 +424,10 @@ export const Panel = memo(function Panel() {
                 <PopoverContent align='start' side='bottom' sideOffset={8}>
                   <PopoverItem
                     onClick={handleAutoLayout}
-                    disabled={isExecuting || !userPermissions.canEdit || isAutoLayouting}
+                    disabled={
+                      isExecuting || !userPermissions.canEdit || isAutoLayouting || hasLockedBlocks
+                    }
+                    title={hasLockedBlocks ? 'Unlock blocks to use auto-layout' : undefined}
                   >
                     <Layout className='h-3 w-3' animate={isAutoLayouting} variant='clockwise' />
                     <span>Auto layout</span>

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/subflows/subflow-node.tsx

@@ -80,6 +80,7 @@ export const SubflowNodeComponent = memo(({ data, id, selected }: NodeProps<Subf
       : undefined
 
   const isEnabled = currentBlock?.enabled ?? true
+  const isLocked = currentBlock?.locked ?? false
   const isPreview = data?.isPreview || false
 
   // Focus state
@@ -200,7 +201,10 @@ export const SubflowNodeComponent = memo(({ data, id, selected }: NodeProps<Subf
                 {blockName}
               </span>
             </div>
-            {!isEnabled && <Badge variant='gray-secondary'>disabled</Badge>}
+            <div className='flex items-center gap-1'>
+              {!isEnabled && <Badge variant='gray-secondary'>disabled</Badge>}
+              {isLocked && <Badge variant='gray-secondary'>locked</Badge>}
+            </div>
           </div>
 
           {!isPreview && (

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/workflow-block/hooks/use-block-state.ts

@@ -18,6 +18,8 @@ export interface UseBlockStateReturn {
   diffStatus: DiffStatus
   /** Whether this is a deleted block in diff mode */
   isDeletedBlock: boolean
+  /** Whether the block is locked */
+  isLocked: boolean
 }
 
 /**
@@ -40,6 +42,11 @@ export function useBlockState(
     ? (data.blockState?.enabled ?? true)
     : (currentBlock?.enabled ?? true)
 
+  // Determine if block is locked
+  const isLocked = data.isPreview
+    ? (data.blockState?.locked ?? false)
+    : (currentBlock?.locked ?? false)
+
   // Get diff status
   const diffStatus: DiffStatus =
     currentWorkflow.isDiffMode && currentBlock && hasDiffStatus(currentBlock)
@@ -68,5 +75,6 @@ export function useBlockState(
     isActive,
     diffStatus,
     isDeletedBlock: isDeletedBlock ?? false,
+    isLocked,
   }
 }

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/workflow-block/workflow-block.tsx

@@ -672,6 +672,7 @@ export const WorkflowBlock = memo(function WorkflowBlock({
     currentWorkflow,
     activeWorkflowId,
     isEnabled,
+    isLocked,
     handleClick,
     hasRing,
     ringStyles,
@@ -1100,7 +1101,7 @@ export const WorkflowBlock = memo(function WorkflowBlock({
               {name}
             </span>
           </div>
-          <div className='relative z-10 flex flex-shrink-0 items-center gap-2'>
+          <div className='relative z-10 flex flex-shrink-0 items-center gap-1'>
             {isWorkflowSelector &&
               childWorkflowId &&
               typeof childIsDeployed === 'boolean' &&
@@ -1133,6 +1134,7 @@ export const WorkflowBlock = memo(function WorkflowBlock({
                 </Tooltip.Root>
               )}
             {!isEnabled && <Badge variant='gray-secondary'>disabled</Badge>}
+            {isLocked && <Badge variant='gray-secondary'>locked</Badge>}
 
             {type === 'schedule' && shouldShowScheduleBadge && scheduleInfo?.isDisabled && (
               <Tooltip.Root>

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-block-visual.ts

@@ -47,6 +47,7 @@ export function useBlockVisual({
     isActive: isExecuting,
     diffStatus,
     isDeletedBlock,
+    isLocked,
   } = useBlockState(blockId, currentWorkflow, data)
 
   const currentBlockId = usePanelEditorStore((state) => state.currentBlockId)
@@ -103,6 +104,7 @@ export function useBlockVisual({
     currentWorkflow,
     activeWorkflowId,
     isEnabled,
+    isLocked,
     handleClick,
     hasRing,
     ringStyles,

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-canvas-context-menu.ts

@@ -31,7 +31,8 @@ export function useCanvasContextMenu({ blocks, getNodes, setNodes }: UseCanvasCo
       nodes.map((n) => {
         const block = blocks[n.id]
         const parentId = block?.data?.parentId
-        const parentType = parentId ? blocks[parentId]?.type : undefined
+        const parentBlock = parentId ? blocks[parentId] : undefined
+        const parentType = parentBlock?.type
         return {
           id: n.id,
           type: block?.type || '',
@@ -39,6 +40,9 @@ export function useCanvasContextMenu({ blocks, getNodes, setNodes }: UseCanvasCo
           horizontalHandles: block?.horizontalHandles ?? false,
           parentId,
           parentType,
+          locked: block?.locked ?? false,
+          isParentLocked: parentBlock?.locked ?? false,
+          isParentDisabled: parentBlock ? !parentBlock.enabled : false,
         }
       }),
     [blocks]

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/utils/auto-layout-utils.ts

@@ -52,6 +52,16 @@ export async function applyAutoLayoutAndUpdateStore(
       return { success: false, error: 'No blocks to layout' }
     }
 
+    // Check for locked blocks - auto-layout is disabled when blocks are locked
+    const hasLockedBlocks = Object.values(blocks).some((block) => block.locked)
+    if (hasLockedBlocks) {
+      logger.info('Auto layout skipped: workflow contains locked blocks', { workflowId })
+      return {
+        success: false,
+        error: 'Auto-layout is disabled when blocks are locked. Unlock blocks to use auto-layout.',
+      }
+    }
+
     // Merge with default options
     const layoutOptions = {
       spacing: {

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/utils/block-protection-utils.ts

@@ -0,0 +1,87 @@
+import type { BlockState } from '@/stores/workflows/workflow/types'
+
+/**
+ * Result of filtering protected blocks from a deletion operation
+ */
+export interface FilterProtectedBlocksResult {
+  /** Block IDs that can be deleted (not protected) */
+  deletableIds: string[]
+  /** Block IDs that are protected and cannot be deleted */
+  protectedIds: string[]
+  /** Whether all blocks are protected (deletion should be cancelled entirely) */
+  allProtected: boolean
+}
+
+/**
+ * Checks if a block is protected from editing/deletion.
+ * A block is protected if it is locked or if its parent container is locked.
+ *
+ * @param blockId - The ID of the block to check
+ * @param blocks - Record of all blocks in the workflow
+ * @returns True if the block is protected
+ */
+export function isBlockProtected(blockId: string, blocks: Record<string, BlockState>): boolean {
+  const block = blocks[blockId]
+  if (!block) return false
+
+  // Block is locked directly
+  if (block.locked) return true
+
+  // Block is inside a locked container
+  const parentId = block.data?.parentId
+  if (parentId && blocks[parentId]?.locked) return true
+
+  return false
+}
+
+/**
+ * Checks if an edge is protected from modification.
+ * An edge is protected if either its source or target block is protected.
+ *
+ * @param edge - The edge to check (must have source and target)
+ * @param blocks - Record of all blocks in the workflow
+ * @returns True if the edge is protected
+ */
+export function isEdgeProtected(
+  edge: { source: string; target: string },
+  blocks: Record<string, BlockState>
+): boolean {
+  return isBlockProtected(edge.source, blocks) || isBlockProtected(edge.target, blocks)
+}
+
+/**
+ * Filters out protected blocks from a list of block IDs for deletion.
+ * Protected blocks are those that are locked or inside a locked container.
+ *
+ * @param blockIds - Array of block IDs to filter
+ * @param blocks - Record of all blocks in the workflow
+ * @returns Result containing deletable IDs, protected IDs, and whether all are protected
+ */
+export function filterProtectedBlocks(
+  blockIds: string[],
+  blocks: Record<string, BlockState>
+): FilterProtectedBlocksResult {
+  const protectedIds = blockIds.filter((id) => isBlockProtected(id, blocks))
+  const deletableIds = blockIds.filter((id) => !protectedIds.includes(id))
+
+  return {
+    deletableIds,
+    protectedIds,
+    allProtected: protectedIds.length === blockIds.length && blockIds.length > 0,
+  }
+}
+
+/**
+ * Checks if any blocks in the selection are protected.
+ * Useful for determining if edit actions should be disabled.
+ *
+ * @param blockIds - Array of block IDs to check
+ * @param blocks - Record of all blocks in the workflow
+ * @returns True if any block is protected
+ */
+export function hasProtectedBlocks(
+  blockIds: string[],
+  blocks: Record<string, BlockState>
+): boolean {
+  return blockIds.some((id) => isBlockProtected(id, blocks))
+}

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/utils/index.ts

@@ -1,4 +1,5 @@
 export * from './auto-layout-utils'
+export * from './block-protection-utils'
 export * from './block-ring-utils'
 export * from './node-position-utils'
 export * from './workflow-canvas-helpers'

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/workflow.tsx

@@ -55,7 +55,10 @@ import {
   clearDragHighlights,
   computeClampedPositionUpdates,
   estimateBlockDimensions,
+  filterProtectedBlocks,
   getClampedPositionForNode,
+  isBlockProtected,
+  isEdgeProtected,
   isInEditableElement,
   resolveParentChildSelectionConflicts,
   validateTriggerPaste,
@@ -543,6 +546,7 @@ const WorkflowContent = React.memo(() => {
     collaborativeBatchRemoveBlocks,
     collaborativeBatchToggleBlockEnabled,
     collaborativeBatchToggleBlockHandles,
+    collaborativeBatchToggleLocked,
     undo,
     redo,
   } = useCollaborativeWorkflow()
@@ -1069,8 +1073,27 @@ const WorkflowContent = React.memo(() => {
 
   const handleContextDelete = useCallback(() => {
     const blockIds = contextMenuBlocks.map((b) => b.id)
-    collaborativeBatchRemoveBlocks(blockIds)
-  }, [contextMenuBlocks, collaborativeBatchRemoveBlocks])
+    const { deletableIds, protectedIds, allProtected } = filterProtectedBlocks(blockIds, blocks)
+
+    if (protectedIds.length > 0) {
+      if (allProtected) {
+        addNotification({
+          level: 'info',
+          message: 'Cannot delete locked blocks or blocks inside locked containers',
+          workflowId: activeWorkflowId || undefined,
+        })
+        return
+      }
+      addNotification({
+        level: 'info',
+        message: `Skipped ${protectedIds.length} protected block(s)`,
+        workflowId: activeWorkflowId || undefined,
+      })
+    }
+    if (deletableIds.length > 0) {
+      collaborativeBatchRemoveBlocks(deletableIds)
+    }
+  }, [contextMenuBlocks, collaborativeBatchRemoveBlocks, addNotification, activeWorkflowId, blocks])
 
   const handleContextToggleEnabled = useCallback(() => {
     const blockIds = contextMenuBlocks.map((block) => block.id)
@@ -1082,6 +1105,11 @@ const WorkflowContent = React.memo(() => {
     collaborativeBatchToggleBlockHandles(blockIds)
   }, [contextMenuBlocks, collaborativeBatchToggleBlockHandles])
 
+  const handleContextToggleLocked = useCallback(() => {
+    const blockIds = contextMenuBlocks.map((block) => block.id)
+    collaborativeBatchToggleLocked(blockIds)
+  }, [contextMenuBlocks, collaborativeBatchToggleLocked])
+
   const handleContextRemoveFromSubflow = useCallback(() => {
     const blocksToRemove = contextMenuBlocks.filter(
       (block) => block.parentId && (block.parentType === 'loop' || block.parentType === 'parallel')
@@ -1951,7 +1979,6 @@ const WorkflowContent = React.memo(() => {
   const loadingWorkflowRef = useRef<string | null>(null)
   const currentWorkflowExists = Boolean(workflows[workflowIdParam])
 
-  /** Initializes workflow when it exists in registry and needs hydration. */
   useEffect(() => {
     const currentId = workflowIdParam
     const currentWorkspaceHydration = hydration.workspaceId
@@ -2128,6 +2155,7 @@ const WorkflowContent = React.memo(() => {
           parentId: block.data?.parentId,
           extent: block.data?.extent || undefined,
           dragHandle: '.workflow-drag-handle',
+          draggable: !isBlockProtected(block.id, blocks),
           data: {
             ...block.data,
             name: block.name,
@@ -2163,6 +2191,7 @@ const WorkflowContent = React.memo(() => {
         position,
         parentId: block.data?.parentId,
         dragHandle,
+        draggable: !isBlockProtected(block.id, blocks),
         extent: (() => {
           // Clamp children to subflow body (exclude header)
           const parentId = block.data?.parentId as string | undefined
@@ -2491,12 +2520,18 @@ const WorkflowContent = React.memo(() => {
       const edgeIdsToRemove = changes
         .filter((change: any) => change.type === 'remove')
         .map((change: any) => change.id)
+        .filter((edgeId: string) => {
+          // Prevent removing edges connected to protected blocks
+          const edge = edges.find((e) => e.id === edgeId)
+          if (!edge) return true
+          return !isEdgeProtected(edge, blocks)
+        })
 
       if (edgeIdsToRemove.length > 0) {
         collaborativeBatchRemoveEdges(edgeIdsToRemove)
       }
     },
-    [collaborativeBatchRemoveEdges]
+    [collaborativeBatchRemoveEdges, edges, blocks]
   )
 
   /**
@@ -2558,6 +2593,16 @@ const WorkflowContent = React.memo(() => {
 
         if (!sourceNode || !targetNode) return
 
+        // Prevent connections to/from protected blocks
+        if (isEdgeProtected(connection, blocks)) {
+          addNotification({
+            level: 'info',
+            message: 'Cannot connect to locked blocks or blocks inside locked containers',
+            workflowId: activeWorkflowId || undefined,
+          })
+          return
+        }
+
         // Get parent information (handle container start node case)
         const sourceParentId =
           blocks[sourceNode.id]?.data?.parentId ||
@@ -2620,7 +2665,7 @@ const WorkflowContent = React.memo(() => {
         connectionCompletedRef.current = true
       }
     },
-    [addEdge, getNodes, blocks]
+    [addEdge, getNodes, blocks, addNotification, activeWorkflowId]
   )
 
   /**
@@ -2715,6 +2760,9 @@ const WorkflowContent = React.memo(() => {
           // Only consider container nodes that aren't the dragged node
           if (n.type !== 'subflowNode' || n.id === node.id) return false
 
+          // Don't allow dropping into locked containers
+          if (blocks[n.id]?.locked) return false
+
           // Get the container's absolute position
           const containerAbsolutePos = getNodeAbsolutePosition(n.id)
 
@@ -2807,6 +2855,11 @@ const WorkflowContent = React.memo(() => {
   /** Captures initial parent ID and position when drag starts. */
   const onNodeDragStart = useCallback(
     (_event: React.MouseEvent, node: any) => {
+      // Prevent dragging protected blocks
+      if (isBlockProtected(node.id, blocks)) {
+        return
+      }
+
       // Store the original parent ID when starting to drag
       const currentParentId = blocks[node.id]?.data?.parentId || null
       setDragStartParentId(currentParentId)
@@ -2835,7 +2888,7 @@ const WorkflowContent = React.memo(() => {
         }
       })
     },
-    [blocks, setDragStartPosition, getNodes, potentialParentId, setPotentialParentId]
+    [blocks, setDragStartPosition, getNodes, setPotentialParentId]
   )
 
   /** Handles node drag stop to establish parent-child relationships. */
@@ -2897,6 +2950,18 @@ const WorkflowContent = React.memo(() => {
       // Don't process parent changes if the node hasn't actually changed parent or is being moved within same parent
       if (potentialParentId === dragStartParentId) return
 
+      // Prevent moving locked blocks out of locked containers
+      // Unlocked blocks (e.g., duplicates) can be moved out freely
+      if (dragStartParentId && blocks[dragStartParentId]?.locked && blocks[node.id]?.locked) {
+        addNotification({
+          level: 'info',
+          message: 'Cannot move locked blocks out of locked containers',
+          workflowId: activeWorkflowId || undefined,
+        })
+        setPotentialParentId(dragStartParentId) // Reset to original parent
+        return
+      }
+
       // Check if this is a starter block - starter blocks should never be in containers
       const isStarterBlock = node.data?.type === 'starter'
       if (isStarterBlock) {
@@ -3293,6 +3358,16 @@ const WorkflowContent = React.memo(() => {
   /** Stable delete handler to avoid creating new function references per edge. */
   const handleEdgeDelete = useCallback(
     (edgeId: string) => {
+      // Prevent removing edges connected to protected blocks
+      const edge = edges.find((e) => e.id === edgeId)
+      if (edge && isEdgeProtected(edge, blocks)) {
+        addNotification({
+          level: 'info',
+          message: 'Cannot remove connections from locked blocks',
+          workflowId: activeWorkflowId || undefined,
+        })
+        return
+      }
       removeEdge(edgeId)
       // Remove this edge from selection (find by edge ID value)
       setSelectedEdges((prev) => {
@@ -3305,7 +3380,7 @@ const WorkflowContent = React.memo(() => {
         return next
       })
     },
-    [removeEdge]
+    [removeEdge, edges, blocks, addNotification, activeWorkflowId]
   )
 
   /** Transforms edges to include selection state and delete handlers. Memoized to prevent re-renders. */
@@ -3346,9 +3421,15 @@ const WorkflowContent = React.memo(() => {
 
       // Handle edge deletion first (edges take priority if selected)
       if (selectedEdges.size > 0) {
-        // Get all selected edge IDs and batch delete them
-        const edgeIds = Array.from(selectedEdges.values())
-        collaborativeBatchRemoveEdges(edgeIds)
+        // Get all selected edge IDs and filter out edges connected to protected blocks
+        const edgeIds = Array.from(selectedEdges.values()).filter((edgeId) => {
+          const edge = edges.find((e) => e.id === edgeId)
+          if (!edge) return true
+          return !isEdgeProtected(edge, blocks)
+        })
+        if (edgeIds.length > 0) {
+          collaborativeBatchRemoveEdges(edgeIds)
+        }
         setSelectedEdges(new Map())
         return
       }
@@ -3365,7 +3446,29 @@ const WorkflowContent = React.memo(() => {
 
       event.preventDefault()
       const selectedIds = selectedNodes.map((node) => node.id)
-      collaborativeBatchRemoveBlocks(selectedIds)
+      const { deletableIds, protectedIds, allProtected } = filterProtectedBlocks(
+        selectedIds,
+        blocks
+      )
+
+      if (protectedIds.length > 0) {
+        if (allProtected) {
+          addNotification({
+            level: 'info',
+            message: 'Cannot delete locked blocks or blocks inside locked containers',
+            workflowId: activeWorkflowId || undefined,
+          })
+          return
+        }
+        addNotification({
+          level: 'info',
+          message: `Skipped ${protectedIds.length} protected block(s)`,
+          workflowId: activeWorkflowId || undefined,
+        })
+      }
+      if (deletableIds.length > 0) {
+        collaborativeBatchRemoveBlocks(deletableIds)
+      }
     }
 
     window.addEventListener('keydown', handleKeyDown)
@@ -3376,6 +3479,10 @@ const WorkflowContent = React.memo(() => {
     getNodes,
     collaborativeBatchRemoveBlocks,
     effectivePermissions.canEdit,
+    blocks,
+    edges,
+    addNotification,
+    activeWorkflowId,
   ])
 
   return (
@@ -3496,12 +3603,18 @@ const WorkflowContent = React.memo(() => {
                 (b) => b.parentId && (b.parentType === 'loop' || b.parentType === 'parallel')
               )}
               canRunFromBlock={runFromBlockState.canRun}
-              disableEdit={!effectivePermissions.canEdit}
+              disableEdit={
+                !effectivePermissions.canEdit ||
+                contextMenuBlocks.some((b) => b.locked || b.isParentLocked)
+              }
+              userCanEdit={effectivePermissions.canEdit}
               isExecuting={isExecuting}
               isPositionalTrigger={
                 contextMenuBlocks.length === 1 &&
                 edges.filter((e) => e.target === contextMenuBlocks[0]?.id).length === 0
               }
+              onToggleLocked={handleContextToggleLocked}
+              canAdmin={effectivePermissions.canAdmin}
             />
 
             <CanvasMenu
@@ -3524,6 +3637,7 @@ const WorkflowContent = React.memo(() => {
               disableEdit={!effectivePermissions.canEdit}
               canUndo={canUndo}
               canRedo={canRedo}
+              hasLockedBlocks={Object.values(blocks).some((b) => b.locked)}
             />
           </>
         )}

apps/sim/components/emcn/components/code/code.tsx

@@ -458,8 +458,8 @@ export function getCodeEditorProps(options?: {
       'caret-[var(--text-primary)] dark:caret-white',
       // Font smoothing
       '[-webkit-font-smoothing:antialiased] [-moz-osx-font-smoothing:grayscale]',
-      // Disable interaction for streaming/preview
-      (isStreaming || isPreview) && 'pointer-events-none'
+      // Disable interaction for streaming/preview/disabled
+      (isStreaming || isPreview || disabled) && 'pointer-events-none'
     ),
   }
 }

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

@@ -212,11 +212,11 @@ export class WorkflowBlockHandler implements BlockHandler {
   /**
    * Parses a potentially nested workflow error message to extract:
    * - The chain of workflow names
-   * - The actual root error message (preserving the block prefix for the failing block)
+   * - The actual root error message (preserving the block name prefix for the failing block)
    *
    * Handles formats like:
    * - "workflow-name" failed: error
-   * - [block_type] Block Name: "workflow-name" failed: error
+   * - Block Name: "workflow-name" failed: error
    * - Workflow chain: A → B | error
    */
   private parseNestedWorkflowError(message: string): { chain: string[]; rootError: string } {
@@ -234,8 +234,8 @@ export class WorkflowBlockHandler implements BlockHandler {
 
     // Extract workflow names from patterns like:
     // - "workflow-name" failed:
-    // - [block_type] Block Name: "workflow-name" failed:
-    const workflowPattern = /(?:\[[^\]]+\]\s*[^:]+:\s*)?"([^"]+)"\s*failed:\s*/g
+    // - Block Name: "workflow-name" failed:
+    const workflowPattern = /(?:\[[^\]]+\]\s*)?(?:[^:]+:\s*)?"([^"]+)"\s*failed:\s*/g
     let match: RegExpExecArray | null
     let lastIndex = 0
 
@@ -247,7 +247,7 @@ export class WorkflowBlockHandler implements BlockHandler {
     }
 
     // The root error is everything after the last match
-    // Keep the block prefix (e.g., [function] Function 1:) so we know which block failed
+    // Keep the block name prefix (e.g., Function 1:) so we know which block failed
     const rootError = lastIndex > 0 ? remaining.slice(lastIndex) : remaining
 
     return { chain, rootError: rootError.trim() || 'Unknown error' }

apps/sim/executor/utils/errors.ts

@@ -47,7 +47,7 @@ export function buildBlockExecutionError(details: BlockExecutionErrorDetails): E
   const blockName = details.block.metadata?.name || details.block.id
   const blockType = details.block.metadata?.id || 'unknown'
 
-  const error = new Error(`[${blockType}] ${blockName}: ${errorMessage}`)
+  const error = new Error(`${blockName}: ${errorMessage}`)
 
   Object.assign(error, {
     blockId: details.block.id,

apps/sim/hooks/use-collaborative-workflow.ts

@@ -409,6 +409,20 @@ export function useCollaborativeWorkflow() {
               logger.info('Successfully applied batch-toggle-handles from remote user')
               break
             }
+            case BLOCKS_OPERATIONS.BATCH_TOGGLE_LOCKED: {
+              const { blockIds } = payload
+              logger.info('Received batch-toggle-locked from remote user', {
+                userId,
+                count: (blockIds || []).length,
+              })
+
+              if (blockIds && blockIds.length > 0) {
+                useWorkflowStore.getState().batchToggleLocked(blockIds)
+              }
+
+              logger.info('Successfully applied batch-toggle-locked from remote user')
+              break
+            }
             case BLOCKS_OPERATIONS.BATCH_UPDATE_PARENT: {
               const { updates } = payload
               logger.info('Received batch-update-parent from remote user', {
@@ -823,14 +837,27 @@ export function useCollaborativeWorkflow() {
 
       if (ids.length === 0) return
 
+      const currentBlocks = useWorkflowStore.getState().blocks
       const previousStates: Record<string, boolean> = {}
       const validIds: string[] = []
 
+      // For each ID, collect non-locked blocks and their children for undo/redo
       for (const id of ids) {
-        const block = useWorkflowStore.getState().blocks[id]
-        if (block) {
-          previousStates[id] = block.enabled
-          validIds.push(id)
+        const block = currentBlocks[id]
+        if (!block) continue
+
+        // Skip locked blocks
+        if (block.locked) continue
+        validIds.push(id)
+        previousStates[id] = block.enabled
+
+        // If it's a loop or parallel, also capture children's previous states for undo/redo
+        if (block.type === 'loop' || block.type === 'parallel') {
+          Object.entries(currentBlocks).forEach(([blockId, b]) => {
+            if (b.data?.parentId === id && !b.locked) {
+              previousStates[blockId] = b.enabled
+            }
+          })
         }
       }
 
@@ -992,12 +1019,25 @@ export function useCollaborativeWorkflow() {
 
       if (ids.length === 0) return
 
+      const blocks = useWorkflowStore.getState().blocks
+
+      // Helper to check if a block is protected (locked or inside locked parent)
+      const isProtected = (blockId: string): boolean => {
+        const block = blocks[blockId]
+        if (!block) return false
+        if (block.locked) return true
+        const parentId = block.data?.parentId
+        if (parentId && blocks[parentId]?.locked) return true
+        return false
+      }
+
       const previousStates: Record<string, boolean> = {}
       const validIds: string[] = []
 
       for (const id of ids) {
-        const block = useWorkflowStore.getState().blocks[id]
-        if (block) {
+        const block = blocks[id]
+        // Skip locked blocks and blocks inside locked containers
+        if (block && !isProtected(id)) {
           previousStates[id] = block.horizontalHandles ?? false
           validIds.push(id)
         }
@@ -1025,6 +1065,58 @@ export function useCollaborativeWorkflow() {
     [isBaselineDiffView, addToQueue, activeWorkflowId, session?.user?.id, undoRedo]
   )
 
+  const collaborativeBatchToggleLocked = useCallback(
+    (ids: string[]) => {
+      if (isBaselineDiffView) {
+        return
+      }
+
+      if (ids.length === 0) return
+
+      const currentBlocks = useWorkflowStore.getState().blocks
+      const previousStates: Record<string, boolean> = {}
+      const validIds: string[] = []
+
+      // For each ID, collect blocks and their children for undo/redo
+      for (const id of ids) {
+        const block = currentBlocks[id]
+        if (!block) continue
+
+        validIds.push(id)
+        previousStates[id] = block.locked ?? false
+
+        // If it's a loop or parallel, also capture children's previous states for undo/redo
+        if (block.type === 'loop' || block.type === 'parallel') {
+          Object.entries(currentBlocks).forEach(([blockId, b]) => {
+            if (b.data?.parentId === id) {
+              previousStates[blockId] = b.locked ?? false
+            }
+          })
+        }
+      }
+
+      if (validIds.length === 0) return
+
+      const operationId = crypto.randomUUID()
+
+      addToQueue({
+        id: operationId,
+        operation: {
+          operation: BLOCKS_OPERATIONS.BATCH_TOGGLE_LOCKED,
+          target: OPERATION_TARGETS.BLOCKS,
+          payload: { blockIds: validIds, previousStates },
+        },
+        workflowId: activeWorkflowId || '',
+        userId: session?.user?.id || 'unknown',
+      })
+
+      useWorkflowStore.getState().batchToggleLocked(validIds)
+
+      undoRedo.recordBatchToggleLocked(validIds, previousStates)
+    },
+    [isBaselineDiffView, addToQueue, activeWorkflowId, session?.user?.id, undoRedo]
+  )
+
   const collaborativeBatchAddEdges = useCallback(
     (edges: Edge[], options?: { skipUndoRedo?: boolean }) => {
       if (isBaselineDiffView) {
@@ -1669,6 +1761,7 @@ export function useCollaborativeWorkflow() {
     collaborativeToggleBlockAdvancedMode,
     collaborativeSetBlockCanonicalMode,
     collaborativeBatchToggleBlockHandles,
+    collaborativeBatchToggleLocked,
     collaborativeBatchAddBlocks,
     collaborativeBatchRemoveBlocks,
     collaborativeBatchAddEdges,

apps/sim/hooks/use-undo-redo.ts

@@ -20,6 +20,7 @@ import {
   type BatchRemoveEdgesOperation,
   type BatchToggleEnabledOperation,
   type BatchToggleHandlesOperation,
+  type BatchToggleLockedOperation,
   type BatchUpdateParentOperation,
   captureLatestEdges,
   captureLatestSubBlockValues,
@@ -415,6 +416,36 @@ export function useUndoRedo() {
     [activeWorkflowId, userId]
   )
 
+  const recordBatchToggleLocked = useCallback(
+    (blockIds: string[], previousStates: Record<string, boolean>) => {
+      if (!activeWorkflowId || blockIds.length === 0) return
+
+      const operation: BatchToggleLockedOperation = {
+        id: crypto.randomUUID(),
+        type: UNDO_REDO_OPERATIONS.BATCH_TOGGLE_LOCKED,
+        timestamp: Date.now(),
+        workflowId: activeWorkflowId,
+        userId,
+        data: { blockIds, previousStates },
+      }
+
+      const inverse: BatchToggleLockedOperation = {
+        id: crypto.randomUUID(),
+        type: UNDO_REDO_OPERATIONS.BATCH_TOGGLE_LOCKED,
+        timestamp: Date.now(),
+        workflowId: activeWorkflowId,
+        userId,
+        data: { blockIds, previousStates },
+      }
+
+      const entry = createOperationEntry(operation, inverse)
+      useUndoRedoStore.getState().push(activeWorkflowId, userId, entry)
+
+      logger.debug('Recorded batch toggle locked', { blockIds, previousStates })
+    },
+    [activeWorkflowId, userId]
+  )
+
   const undo = useCallback(async () => {
     if (!activeWorkflowId) return
 
@@ -777,7 +808,9 @@ export function useUndoRedo() {
           const toggleOp = entry.inverse as BatchToggleEnabledOperation
           const { blockIds, previousStates } = toggleOp.data
 
-          const validBlockIds = blockIds.filter((id) => useWorkflowStore.getState().blocks[id])
+          // Restore all blocks in previousStates (includes children of containers)
+          const allBlockIds = Object.keys(previousStates)
+          const validBlockIds = allBlockIds.filter((id) => useWorkflowStore.getState().blocks[id])
           if (validBlockIds.length === 0) {
             logger.debug('Undo batch-toggle-enabled skipped; no blocks exist')
             break
@@ -788,14 +821,14 @@ export function useUndoRedo() {
             operation: {
               operation: BLOCKS_OPERATIONS.BATCH_TOGGLE_ENABLED,
               target: OPERATION_TARGETS.BLOCKS,
-              payload: { blockIds: validBlockIds, previousStates },
+              payload: { blockIds, previousStates },
             },
             workflowId: activeWorkflowId,
             userId,
           })
 
           // Use setBlockEnabled to directly restore to previous state
-          // This is more robust than conditional toggle in collaborative scenarios
+          // This restores all affected blocks including children of containers
           validBlockIds.forEach((blockId) => {
             useWorkflowStore.getState().setBlockEnabled(blockId, previousStates[blockId])
           })
@@ -829,6 +862,36 @@ export function useUndoRedo() {
           })
           break
         }
+        case UNDO_REDO_OPERATIONS.BATCH_TOGGLE_LOCKED: {
+          const toggleOp = entry.inverse as BatchToggleLockedOperation
+          const { blockIds, previousStates } = toggleOp.data
+
+          // Restore all blocks in previousStates (includes children of containers)
+          const allBlockIds = Object.keys(previousStates)
+          const validBlockIds = allBlockIds.filter((id) => useWorkflowStore.getState().blocks[id])
+          if (validBlockIds.length === 0) {
+            logger.debug('Undo batch-toggle-locked skipped; no blocks exist')
+            break
+          }
+
+          addToQueue({
+            id: opId,
+            operation: {
+              operation: BLOCKS_OPERATIONS.BATCH_TOGGLE_LOCKED,
+              target: OPERATION_TARGETS.BLOCKS,
+              payload: { blockIds, previousStates },
+            },
+            workflowId: activeWorkflowId,
+            userId,
+          })
+
+          // Use setBlockLocked to directly restore to previous state
+          // This restores all affected blocks including children of containers
+          validBlockIds.forEach((blockId) => {
+            useWorkflowStore.getState().setBlockLocked(blockId, previousStates[blockId])
+          })
+          break
+        }
         case UNDO_REDO_OPERATIONS.APPLY_DIFF: {
           const applyDiffInverse = entry.inverse as any
           const { baselineSnapshot } = applyDiffInverse.data
@@ -1365,7 +1428,9 @@ export function useUndoRedo() {
           const toggleOp = entry.operation as BatchToggleEnabledOperation
           const { blockIds, previousStates } = toggleOp.data
 
-          const validBlockIds = blockIds.filter((id) => useWorkflowStore.getState().blocks[id])
+          // Process all blocks in previousStates (includes children of containers)
+          const allBlockIds = Object.keys(previousStates)
+          const validBlockIds = allBlockIds.filter((id) => useWorkflowStore.getState().blocks[id])
           if (validBlockIds.length === 0) {
             logger.debug('Redo batch-toggle-enabled skipped; no blocks exist')
             break
@@ -1376,16 +1441,18 @@ export function useUndoRedo() {
             operation: {
               operation: BLOCKS_OPERATIONS.BATCH_TOGGLE_ENABLED,
               target: OPERATION_TARGETS.BLOCKS,
-              payload: { blockIds: validBlockIds, previousStates },
+              payload: { blockIds, previousStates },
             },
             workflowId: activeWorkflowId,
             userId,
           })
 
-          // Use setBlockEnabled to directly set to toggled state
-          // Redo sets to !previousStates (the state after the original toggle)
+          // Compute target state the same way batchToggleEnabled does:
+          // use !firstBlock.enabled, where firstBlock is blockIds[0]
+          const firstBlockId = blockIds[0]
+          const targetEnabled = !previousStates[firstBlockId]
           validBlockIds.forEach((blockId) => {
-            useWorkflowStore.getState().setBlockEnabled(blockId, !previousStates[blockId])
+            useWorkflowStore.getState().setBlockEnabled(blockId, targetEnabled)
           })
           break
         }
@@ -1417,6 +1484,38 @@ export function useUndoRedo() {
           })
           break
         }
+        case UNDO_REDO_OPERATIONS.BATCH_TOGGLE_LOCKED: {
+          const toggleOp = entry.operation as BatchToggleLockedOperation
+          const { blockIds, previousStates } = toggleOp.data
+
+          // Process all blocks in previousStates (includes children of containers)
+          const allBlockIds = Object.keys(previousStates)
+          const validBlockIds = allBlockIds.filter((id) => useWorkflowStore.getState().blocks[id])
+          if (validBlockIds.length === 0) {
+            logger.debug('Redo batch-toggle-locked skipped; no blocks exist')
+            break
+          }
+
+          addToQueue({
+            id: opId,
+            operation: {
+              operation: BLOCKS_OPERATIONS.BATCH_TOGGLE_LOCKED,
+              target: OPERATION_TARGETS.BLOCKS,
+              payload: { blockIds, previousStates },
+            },
+            workflowId: activeWorkflowId,
+            userId,
+          })
+
+          // Compute target state the same way batchToggleLocked does:
+          // use !firstBlock.locked, where firstBlock is blockIds[0]
+          const firstBlockId = blockIds[0]
+          const targetLocked = !previousStates[firstBlockId]
+          validBlockIds.forEach((blockId) => {
+            useWorkflowStore.getState().setBlockLocked(blockId, targetLocked)
+          })
+          break
+        }
         case UNDO_REDO_OPERATIONS.APPLY_DIFF: {
           // Redo apply-diff means re-applying the proposed state with diff markers
           const applyDiffOp = entry.operation as any
@@ -1738,6 +1837,7 @@ export function useUndoRedo() {
     recordBatchUpdateParent,
     recordBatchToggleEnabled,
     recordBatchToggleHandles,
+    recordBatchToggleLocked,
     recordApplyDiff,
     recordAcceptDiff,
     recordRejectDiff,

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

@@ -54,6 +54,7 @@ type SkippedItemType =
   | 'block_not_found'
   | 'invalid_block_type'
   | 'block_not_allowed'
+  | 'block_locked'
   | 'tool_not_allowed'
   | 'invalid_edge_target'
   | 'invalid_edge_source'
@@ -618,6 +619,7 @@ function createBlockFromParams(
     subBlocks: {},
     outputs: outputs,
     data: parentId ? { parentId, extent: 'parent' as const } : {},
+    locked: false,
   }
 
   // Add validated inputs as subBlocks
@@ -1520,6 +1522,24 @@ function applyOperationsToWorkflowState(
           break
         }
 
+        // Check if block is locked or inside a locked container
+        const deleteBlock = modifiedState.blocks[block_id]
+        const deleteParentId = deleteBlock.data?.parentId as string | undefined
+        const deleteParentLocked = deleteParentId
+          ? modifiedState.blocks[deleteParentId]?.locked
+          : false
+        if (deleteBlock.locked || deleteParentLocked) {
+          logSkippedItem(skippedItems, {
+            type: 'block_locked',
+            operationType: 'delete',
+            blockId: block_id,
+            reason: deleteParentLocked
+              ? `Block "${block_id}" is inside locked container "${deleteParentId}" and cannot be deleted`
+              : `Block "${block_id}" is locked and cannot be deleted`,
+          })
+          break
+        }
+
         // Find all child blocks to remove
         const blocksToRemove = new Set<string>([block_id])
         const findChildren = (parentId: string) => {
@@ -1555,6 +1575,21 @@ function applyOperationsToWorkflowState(
 
         const block = modifiedState.blocks[block_id]
 
+        // Check if block is locked or inside a locked container
+        const editParentId = block.data?.parentId as string | undefined
+        const editParentLocked = editParentId ? modifiedState.blocks[editParentId]?.locked : false
+        if (block.locked || editParentLocked) {
+          logSkippedItem(skippedItems, {
+            type: 'block_locked',
+            operationType: 'edit',
+            blockId: block_id,
+            reason: editParentLocked
+              ? `Block "${block_id}" is inside locked container "${editParentId}" and cannot be edited`
+              : `Block "${block_id}" is locked and cannot be edited`,
+          })
+          break
+        }
+
         // Ensure block has essential properties
         if (!block.type) {
           logger.warn(`Block ${block_id} missing type property, skipping edit`, {
@@ -2122,6 +2157,19 @@ function applyOperationsToWorkflowState(
 
         // Handle nested nodes (for loops/parallels created from scratch)
         if (params.nestedNodes) {
+          // Defensive check: verify parent is not locked before adding children
+          // (Parent was just created with locked: false, but check for consistency)
+          const parentBlock = modifiedState.blocks[block_id]
+          if (parentBlock?.locked) {
+            logSkippedItem(skippedItems, {
+              type: 'block_locked',
+              operationType: 'add_nested_nodes',
+              blockId: block_id,
+              reason: `Container "${block_id}" is locked - cannot add nested nodes`,
+            })
+            break
+          }
+
           Object.entries(params.nestedNodes).forEach(([childId, childBlock]: [string, any]) => {
             // Validate childId is a valid string
             if (!isValidKey(childId)) {
@@ -2209,6 +2257,18 @@ function applyOperationsToWorkflowState(
           break
         }
 
+        // Check if subflow is locked
+        if (subflowBlock.locked) {
+          logSkippedItem(skippedItems, {
+            type: 'block_locked',
+            operationType: 'insert_into_subflow',
+            blockId: block_id,
+            reason: `Subflow "${subflowId}" is locked - cannot insert block "${block_id}"`,
+            details: { subflowId },
+          })
+          break
+        }
+
         if (subflowBlock.type !== 'loop' && subflowBlock.type !== 'parallel') {
           logger.error('Subflow block has invalid type', {
             subflowId,
@@ -2247,6 +2307,17 @@ function applyOperationsToWorkflowState(
             break
           }
 
+          // Check if existing block is locked
+          if (existingBlock.locked) {
+            logSkippedItem(skippedItems, {
+              type: 'block_locked',
+              operationType: 'insert_into_subflow',
+              blockId: block_id,
+              reason: `Block "${block_id}" is locked and cannot be moved into a subflow`,
+            })
+            break
+          }
+
           // Moving existing block into subflow - just update parent
           existingBlock.data = {
             ...existingBlock.data,
@@ -2392,6 +2463,30 @@ function applyOperationsToWorkflowState(
           break
         }
 
+        // Check if block is locked
+        if (block.locked) {
+          logSkippedItem(skippedItems, {
+            type: 'block_locked',
+            operationType: 'extract_from_subflow',
+            blockId: block_id,
+            reason: `Block "${block_id}" is locked and cannot be extracted from subflow`,
+          })
+          break
+        }
+
+        // Check if parent subflow is locked
+        const parentSubflow = modifiedState.blocks[subflowId]
+        if (parentSubflow?.locked) {
+          logSkippedItem(skippedItems, {
+            type: 'block_locked',
+            operationType: 'extract_from_subflow',
+            blockId: block_id,
+            reason: `Subflow "${subflowId}" is locked - cannot extract block "${block_id}"`,
+            details: { subflowId },
+          })
+          break
+        }
+
         // Verify it's actually a child of this subflow
         if (block.data?.parentId !== subflowId) {
           logger.warn('Block is not a child of specified subflow', {

apps/sim/lib/workflows/comparison/compare.test.ts

@@ -296,6 +296,26 @@ describe('hasWorkflowChanged', () => {
       })
       expect(hasWorkflowChanged(state1, state2)).toBe(true)
     })
+
+    it.concurrent('should detect locked/unlocked changes', () => {
+      const state1 = createWorkflowState({
+        blocks: { block1: createBlock('block1', { locked: false }) },
+      })
+      const state2 = createWorkflowState({
+        blocks: { block1: createBlock('block1', { locked: true }) },
+      })
+      expect(hasWorkflowChanged(state1, state2)).toBe(true)
+    })
+
+    it.concurrent('should not detect changes when locked state is the same', () => {
+      const state1 = createWorkflowState({
+        blocks: { block1: createBlock('block1', { locked: true }) },
+      })
+      const state2 = createWorkflowState({
+        blocks: { block1: createBlock('block1', { locked: true }) },
+      })
+      expect(hasWorkflowChanged(state1, state2)).toBe(false)
+    })
   })
 
   describe('SubBlock Changes', () => {

apps/sim/lib/workflows/comparison/compare.ts

@@ -157,7 +157,7 @@ export function generateWorkflowDiffSummary(
       }
       // Check other block properties (boolean fields)
       // Use !! to normalize: null/undefined/false are all equivalent (falsy)
-      const blockFields = ['horizontalHandles', 'advancedMode', 'triggerMode'] as const
+      const blockFields = ['horizontalHandles', 'advancedMode', 'triggerMode', 'locked'] as const
       for (const field of blockFields) {
         if (!!currentBlock[field] !== !!previousBlock[field]) {
           changes.push({

apps/sim/lib/workflows/defaults.ts

@@ -100,6 +100,7 @@ function buildStartBlockState(
     triggerMode: false,
     height: 0,
     data: {},
+    locked: false,
   }
 
   return { blockState, subBlockValues }

apps/sim/lib/workflows/diff/diff-engine.test.ts

@@ -0,0 +1,173 @@
+/**
+ * @vitest-environment node
+ */
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import type { BlockState, WorkflowState } from '@/stores/workflows/workflow/types'
+
+// Mock all external dependencies before imports
+vi.mock('@sim/logger', () => ({
+  createLogger: () => ({
+    info: vi.fn(),
+    warn: vi.fn(),
+    error: vi.fn(),
+    debug: vi.fn(),
+  }),
+}))
+
+vi.mock('@/stores/workflows/workflow/store', () => ({
+  useWorkflowStore: {
+    getState: () => ({
+      getWorkflowState: () => ({ blocks: {}, edges: [], loops: {}, parallels: {} }),
+    }),
+  },
+}))
+
+vi.mock('@/stores/workflows/utils', () => ({
+  mergeSubblockState: (blocks: Record<string, BlockState>) => blocks,
+}))
+
+vi.mock('@/lib/workflows/sanitization/key-validation', () => ({
+  isValidKey: (key: string) => key !== 'undefined' && key !== 'null' && key !== '',
+}))
+
+vi.mock('@/lib/workflows/autolayout', () => ({
+  transferBlockHeights: vi.fn(),
+  applyTargetedLayout: (blocks: Record<string, BlockState>) => blocks,
+  applyAutoLayout: () => ({ success: true, blocks: {} }),
+}))
+
+vi.mock('@/lib/workflows/autolayout/constants', () => ({
+  DEFAULT_HORIZONTAL_SPACING: 500,
+  DEFAULT_VERTICAL_SPACING: 400,
+  DEFAULT_LAYOUT_OPTIONS: {},
+}))
+
+vi.mock('@/stores/workflows/workflow/utils', () => ({
+  generateLoopBlocks: () => ({}),
+  generateParallelBlocks: () => ({}),
+}))
+
+import { WorkflowDiffEngine } from './diff-engine'
+
+function createMockBlock(overrides: Partial<BlockState> = {}): BlockState {
+  return {
+    id: 'block-1',
+    type: 'agent',
+    name: 'Test Block',
+    enabled: true,
+    position: { x: 0, y: 0 },
+    subBlocks: {},
+    outputs: {},
+    ...overrides,
+  } as BlockState
+}
+
+function createMockWorkflowState(blocks: Record<string, BlockState>): WorkflowState {
+  return {
+    blocks,
+    edges: [],
+    loops: {},
+    parallels: {},
+  }
+}
+
+describe('WorkflowDiffEngine', () => {
+  let engine: WorkflowDiffEngine
+
+  beforeEach(() => {
+    engine = new WorkflowDiffEngine()
+    vi.clearAllMocks()
+  })
+
+  describe('hasBlockChanged detection', () => {
+    describe('locked state changes', () => {
+      it.concurrent(
+        'should detect when block locked state changes from false to true',
+        async () => {
+          const freshEngine = new WorkflowDiffEngine()
+          const baseline = createMockWorkflowState({
+            'block-1': createMockBlock({ id: 'block-1', locked: false }),
+          })
+
+          const proposed = createMockWorkflowState({
+            'block-1': createMockBlock({ id: 'block-1', locked: true }),
+          })
+
+          const result = await freshEngine.createDiffFromWorkflowState(
+            proposed,
+            undefined,
+            baseline
+          )
+
+          expect(result.success).toBe(true)
+          expect(result.diff?.diffAnalysis?.edited_blocks).toContain('block-1')
+        }
+      )
+
+      it.concurrent('should not detect change when locked state is the same', async () => {
+        const freshEngine = new WorkflowDiffEngine()
+        const baseline = createMockWorkflowState({
+          'block-1': createMockBlock({ id: 'block-1', locked: true }),
+        })
+
+        const proposed = createMockWorkflowState({
+          'block-1': createMockBlock({ id: 'block-1', locked: true }),
+        })
+
+        const result = await freshEngine.createDiffFromWorkflowState(proposed, undefined, baseline)
+
+        expect(result.success).toBe(true)
+        expect(result.diff?.diffAnalysis?.edited_blocks).not.toContain('block-1')
+      })
+
+      it.concurrent('should detect change when locked goes from undefined to true', async () => {
+        const freshEngine = new WorkflowDiffEngine()
+        const baseline = createMockWorkflowState({
+          'block-1': createMockBlock({ id: 'block-1' }), // locked undefined
+        })
+
+        const proposed = createMockWorkflowState({
+          'block-1': createMockBlock({ id: 'block-1', locked: true }),
+        })
+
+        const result = await freshEngine.createDiffFromWorkflowState(proposed, undefined, baseline)
+
+        expect(result.success).toBe(true)
+        // The hasBlockChanged function uses !!locked for comparison
+        // so undefined -> true should be detected as a change
+        expect(result.diff?.diffAnalysis?.edited_blocks).toContain('block-1')
+      })
+
+      it.concurrent('should not detect change when both locked states are falsy', async () => {
+        const freshEngine = new WorkflowDiffEngine()
+        const baseline = createMockWorkflowState({
+          'block-1': createMockBlock({ id: 'block-1' }), // locked undefined
+        })
+
+        const proposed = createMockWorkflowState({
+          'block-1': createMockBlock({ id: 'block-1', locked: false }), // locked false
+        })
+
+        const result = await freshEngine.createDiffFromWorkflowState(proposed, undefined, baseline)
+
+        expect(result.success).toBe(true)
+        // undefined and false should both be falsy, so !! comparison makes them equal
+        expect(result.diff?.diffAnalysis?.edited_blocks).not.toContain('block-1')
+      })
+    })
+  })
+
+  describe('diff lifecycle', () => {
+    it.concurrent('should start with no diff', () => {
+      const freshEngine = new WorkflowDiffEngine()
+      expect(freshEngine.hasDiff()).toBe(false)
+      expect(freshEngine.getCurrentDiff()).toBeUndefined()
+    })
+
+    it.concurrent('should clear diff', () => {
+      const freshEngine = new WorkflowDiffEngine()
+      freshEngine.clearDiff()
+      expect(freshEngine.hasDiff()).toBe(false)
+    })
+  })
+})

apps/sim/lib/workflows/diff/diff-engine.ts

@@ -215,6 +215,7 @@ function hasBlockChanged(currentBlock: BlockState, proposedBlock: BlockState): b
   if (currentBlock.name !== proposedBlock.name) return true
   if (currentBlock.enabled !== proposedBlock.enabled) return true
   if (currentBlock.triggerMode !== proposedBlock.triggerMode) return true
+  if (!!currentBlock.locked !== !!proposedBlock.locked) return true
 
   // Compare subBlocks
   const currentSubKeys = Object.keys(currentBlock.subBlocks || {})

apps/sim/lib/workflows/persistence/duplicate.ts

@@ -189,6 +189,7 @@ export async function duplicateWorkflow(
           parentId: newParentId,
           extent: newExtent,
           data: updatedData,
+          locked: false, // Duplicated blocks should always be unlocked
           createdAt: now,
           updatedAt: now,
         }

apps/sim/lib/workflows/persistence/utils.ts

@@ -226,6 +226,7 @@ export async function loadWorkflowFromNormalizedTables(
         subBlocks: (block.subBlocks as BlockState['subBlocks']) || {},
         outputs: (block.outputs as BlockState['outputs']) || {},
         data: blockData,
+        locked: block.locked,
       }
 
       blocksMap[block.id] = assembled
@@ -363,6 +364,7 @@ export async function saveWorkflowToNormalizedTables(
           data: block.data || {},
           parentId: block.data?.parentId || null,
           extent: block.data?.extent || null,
+          locked: block.locked ?? false,
         }))
 
         await tx.insert(workflowBlocks).values(blockInserts)
@@ -627,7 +629,8 @@ export function regenerateWorkflowStateIds(state: RegenerateStateInput): Regener
   // Regenerate blocks with updated references
   Object.entries(state.blocks || {}).forEach(([oldId, block]) => {
     const newId = blockIdMapping.get(oldId)!
-    const newBlock: BlockState = { ...block, id: newId }
+    // Duplicated blocks are always unlocked so users can edit them
+    const newBlock: BlockState = { ...block, id: newId, locked: false }
 
     // Update parentId reference if it exists
     if (newBlock.data?.parentId) {

apps/sim/socket/constants.ts

@@ -17,6 +17,7 @@ export const BLOCKS_OPERATIONS = {
   BATCH_TOGGLE_ENABLED: 'batch-toggle-enabled',
   BATCH_TOGGLE_HANDLES: 'batch-toggle-handles',
   BATCH_UPDATE_PARENT: 'batch-update-parent',
+  BATCH_TOGGLE_LOCKED: 'batch-toggle-locked',
 } as const
 
 export type BlocksOperation = (typeof BLOCKS_OPERATIONS)[keyof typeof BLOCKS_OPERATIONS]
@@ -85,6 +86,7 @@ export const UNDO_REDO_OPERATIONS = {
   BATCH_UPDATE_PARENT: 'batch-update-parent',
   BATCH_TOGGLE_ENABLED: 'batch-toggle-enabled',
   BATCH_TOGGLE_HANDLES: 'batch-toggle-handles',
+  BATCH_TOGGLE_LOCKED: 'batch-toggle-locked',
   APPLY_DIFF: 'apply-diff',
   ACCEPT_DIFF: 'accept-diff',
   REJECT_DIFF: 'reject-diff',

apps/sim/socket/database/operations.ts

@@ -507,7 +507,37 @@ async function handleBlocksOperationTx(
       })
 
       if (blocks && blocks.length > 0) {
-        const blockValues = blocks.map((block: Record<string, unknown>) => {
+        // Fetch existing blocks to check for locked parents
+        const existingBlocks = await tx
+          .select({ id: workflowBlocks.id, locked: workflowBlocks.locked })
+          .from(workflowBlocks)
+          .where(eq(workflowBlocks.workflowId, workflowId))
+
+        type ExistingBlockRecord = (typeof existingBlocks)[number]
+        const lockedParentIds = new Set(
+          existingBlocks
+            .filter((b: ExistingBlockRecord) => b.locked)
+            .map((b: ExistingBlockRecord) => b.id)
+        )
+
+        // Filter out blocks being added to locked parents
+        const allowedBlocks = (blocks as Array<Record<string, unknown>>).filter((block) => {
+          const parentId = (block.data as Record<string, unknown> | null)?.parentId as
+            | string
+            | undefined
+          if (parentId && lockedParentIds.has(parentId)) {
+            logger.info(`Skipping block ${block.id} - parent ${parentId} is locked`)
+            return false
+          }
+          return true
+        })
+
+        if (allowedBlocks.length === 0) {
+          logger.info('All blocks filtered out due to locked parents, skipping add')
+          break
+        }
+
+        const blockValues = allowedBlocks.map((block: Record<string, unknown>) => {
           const blockId = block.id as string
           const mergedSubBlocks = mergeSubBlockValues(
             block.subBlocks as Record<string, unknown>,
@@ -529,6 +559,7 @@ async function handleBlocksOperationTx(
             advancedMode: (block.advancedMode as boolean) ?? false,
             triggerMode: (block.triggerMode as boolean) ?? false,
             height: (block.height as number) || 0,
+            locked: (block.locked as boolean) ?? false,
           }
         })
 
@@ -537,7 +568,7 @@ async function handleBlocksOperationTx(
         // Create subflow entries for loop/parallel blocks (skip if already in payload)
         const loopIds = new Set(loops ? Object.keys(loops) : [])
         const parallelIds = new Set(parallels ? Object.keys(parallels) : [])
-        for (const block of blocks) {
+        for (const block of allowedBlocks) {
           const blockId = block.id as string
           if (block.type === 'loop' && !loopIds.has(blockId)) {
             await tx.insert(workflowSubflows).values({
@@ -566,7 +597,7 @@ async function handleBlocksOperationTx(
 
         // Update parent subflow node lists
         const parentIds = new Set<string>()
-        for (const block of blocks) {
+        for (const block of allowedBlocks) {
           const parentId = (block.data as Record<string, unknown>)?.parentId as string | undefined
           if (parentId) {
             parentIds.add(parentId)
@@ -624,44 +655,74 @@ async function handleBlocksOperationTx(
 
       logger.info(`Batch removing ${ids.length} blocks from workflow ${workflowId}`)
 
+      // Fetch all blocks to check lock status and filter out protected blocks
+      const allBlocks = await tx
+        .select({
+          id: workflowBlocks.id,
+          type: workflowBlocks.type,
+          locked: workflowBlocks.locked,
+          data: workflowBlocks.data,
+        })
+        .from(workflowBlocks)
+        .where(eq(workflowBlocks.workflowId, workflowId))
+
+      type BlockRecord = (typeof allBlocks)[number]
+      const blocksById: Record<string, BlockRecord> = Object.fromEntries(
+        allBlocks.map((b: BlockRecord) => [b.id, b])
+      )
+
+      // Helper to check if a block is protected (locked or inside locked parent)
+      const isProtected = (blockId: string): boolean => {
+        const block = blocksById[blockId]
+        if (!block) return false
+        if (block.locked) return true
+        const parentId = (block.data as Record<string, unknown> | null)?.parentId as
+          | string
+          | undefined
+        if (parentId && blocksById[parentId]?.locked) return true
+        return false
+      }
+
+      // Filter out protected blocks from deletion request
+      const deletableIds = ids.filter((id) => !isProtected(id))
+      if (deletableIds.length === 0) {
+        logger.info('All requested blocks are protected, skipping deletion')
+        return
+      }
+
+      if (deletableIds.length < ids.length) {
+        logger.info(
+          `Filtered out ${ids.length - deletableIds.length} protected blocks from deletion`
+        )
+      }
+
       // Collect all block IDs including children of subflows
-      const allBlocksToDelete = new Set<string>(ids)
+      const allBlocksToDelete = new Set<string>(deletableIds)
 
-      for (const id of ids) {
-        const blockToRemove = await tx
-          .select({ type: workflowBlocks.type })
-          .from(workflowBlocks)
-          .where(and(eq(workflowBlocks.id, id), eq(workflowBlocks.workflowId, workflowId)))
-          .limit(1)
-
-        if (blockToRemove.length > 0 && isSubflowBlockType(blockToRemove[0].type)) {
-          const childBlocks = await tx
-            .select({ id: workflowBlocks.id })
-            .from(workflowBlocks)
-            .where(
-              and(
-                eq(workflowBlocks.workflowId, workflowId),
-                sql`${workflowBlocks.data}->>'parentId' = ${id}`
-              )
-            )
-
-          childBlocks.forEach((child: { id: string }) => allBlocksToDelete.add(child.id))
+      for (const id of deletableIds) {
+        const block = blocksById[id]
+        if (block && isSubflowBlockType(block.type)) {
+          // Include all children of the subflow (they should be deleted with parent)
+          for (const b of allBlocks) {
+            const parentId = (b.data as Record<string, unknown> | null)?.parentId
+            if (parentId === id) {
+              allBlocksToDelete.add(b.id)
+            }
+          }
         }
       }
 
       const blockIdsArray = Array.from(allBlocksToDelete)
 
-      // Collect parent IDs BEFORE deleting blocks
+      // Collect parent IDs BEFORE deleting blocks (use blocksById, already fetched)
       const parentIds = new Set<string>()
-      for (const id of ids) {
-        const parentInfo = await tx
-          .select({ parentId: sql<string | null>`${workflowBlocks.data}->>'parentId'` })
-          .from(workflowBlocks)
-          .where(and(eq(workflowBlocks.id, id), eq(workflowBlocks.workflowId, workflowId)))
-          .limit(1)
-
-        if (parentInfo.length > 0 && parentInfo[0].parentId) {
-          parentIds.add(parentInfo[0].parentId)
+      for (const id of deletableIds) {
+        const block = blocksById[id]
+        const parentId = (block?.data as Record<string, unknown> | null)?.parentId as
+          | string
+          | undefined
+        if (parentId) {
+          parentIds.add(parentId)
         }
       }
 
@@ -741,22 +802,61 @@ async function handleBlocksOperationTx(
         `Batch toggling enabled state for ${blockIds.length} blocks in workflow ${workflowId}`
       )
 
-      const blocks = await tx
-        .select({ id: workflowBlocks.id, enabled: workflowBlocks.enabled })
+      // Get all blocks in workflow to find children and check locked state
+      const allBlocks = await tx
+        .select({
+          id: workflowBlocks.id,
+          enabled: workflowBlocks.enabled,
+          locked: workflowBlocks.locked,
+          type: workflowBlocks.type,
+          data: workflowBlocks.data,
+        })
         .from(workflowBlocks)
-        .where(and(eq(workflowBlocks.workflowId, workflowId), inArray(workflowBlocks.id, blockIds)))
+        .where(eq(workflowBlocks.workflowId, workflowId))
 
-      for (const block of blocks) {
+      type BlockRecord = (typeof allBlocks)[number]
+      const blocksById: Record<string, BlockRecord> = Object.fromEntries(
+        allBlocks.map((b: BlockRecord) => [b.id, b])
+      )
+      const blocksToToggle = new Set<string>()
+
+      // Collect all blocks to toggle including children of containers
+      for (const id of blockIds) {
+        const block = blocksById[id]
+        if (!block || block.locked) continue
+
+        blocksToToggle.add(id)
+
+        // If it's a loop or parallel, also include all children
+        if (block.type === 'loop' || block.type === 'parallel') {
+          for (const b of allBlocks) {
+            const parentId = (b.data as Record<string, unknown> | null)?.parentId
+            if (parentId === id && !b.locked) {
+              blocksToToggle.add(b.id)
+            }
+          }
+        }
+      }
+
+      // Determine target enabled state based on first toggleable block
+      if (blocksToToggle.size === 0) break
+      const firstToggleableId = Array.from(blocksToToggle)[0]
+      const firstBlock = blocksById[firstToggleableId]
+      if (!firstBlock) break
+      const targetEnabled = !firstBlock.enabled
+
+      // Update all affected blocks
+      for (const blockId of blocksToToggle) {
         await tx
           .update(workflowBlocks)
           .set({
-            enabled: !block.enabled,
+            enabled: targetEnabled,
             updatedAt: new Date(),
           })
-          .where(and(eq(workflowBlocks.id, block.id), eq(workflowBlocks.workflowId, workflowId)))
+          .where(and(eq(workflowBlocks.id, blockId), eq(workflowBlocks.workflowId, workflowId)))
       }
 
-      logger.debug(`Batch toggled enabled state for ${blocks.length} blocks`)
+      logger.debug(`Batch toggled enabled state for ${blocksToToggle.size} blocks`)
       break
     }
 
@@ -768,22 +868,118 @@ async function handleBlocksOperationTx(
 
       logger.info(`Batch toggling handles for ${blockIds.length} blocks in workflow ${workflowId}`)
 
-      const blocks = await tx
-        .select({ id: workflowBlocks.id, horizontalHandles: workflowBlocks.horizontalHandles })
+      // Fetch all blocks to check lock status and filter out protected blocks
+      const allBlocks = await tx
+        .select({
+          id: workflowBlocks.id,
+          horizontalHandles: workflowBlocks.horizontalHandles,
+          locked: workflowBlocks.locked,
+          data: workflowBlocks.data,
+        })
         .from(workflowBlocks)
-        .where(and(eq(workflowBlocks.workflowId, workflowId), inArray(workflowBlocks.id, blockIds)))
+        .where(eq(workflowBlocks.workflowId, workflowId))
 
-      for (const block of blocks) {
+      type HandleBlockRecord = (typeof allBlocks)[number]
+      const blocksById: Record<string, HandleBlockRecord> = Object.fromEntries(
+        allBlocks.map((b: HandleBlockRecord) => [b.id, b])
+      )
+
+      // Helper to check if a block is protected (locked or inside locked parent)
+      const isProtected = (blockId: string): boolean => {
+        const block = blocksById[blockId]
+        if (!block) return false
+        if (block.locked) return true
+        const parentId = (block.data as Record<string, unknown> | null)?.parentId as
+          | string
+          | undefined
+        if (parentId && blocksById[parentId]?.locked) return true
+        return false
+      }
+
+      // Filter to only toggle handles on unprotected blocks
+      const blocksToToggle = blockIds.filter((id) => blocksById[id] && !isProtected(id))
+      if (blocksToToggle.length === 0) {
+        logger.info('All requested blocks are protected, skipping handles toggle')
+        break
+      }
+
+      for (const blockId of blocksToToggle) {
+        const block = blocksById[blockId]
         await tx
           .update(workflowBlocks)
           .set({
             horizontalHandles: !block.horizontalHandles,
             updatedAt: new Date(),
           })
-          .where(and(eq(workflowBlocks.id, block.id), eq(workflowBlocks.workflowId, workflowId)))
+          .where(and(eq(workflowBlocks.id, blockId), eq(workflowBlocks.workflowId, workflowId)))
       }
 
-      logger.debug(`Batch toggled handles for ${blocks.length} blocks`)
+      logger.debug(`Batch toggled handles for ${blocksToToggle.length} blocks`)
+      break
+    }
+
+    case BLOCKS_OPERATIONS.BATCH_TOGGLE_LOCKED: {
+      const { blockIds } = payload
+      if (!Array.isArray(blockIds) || blockIds.length === 0) {
+        return
+      }
+
+      logger.info(`Batch toggling locked for ${blockIds.length} blocks in workflow ${workflowId}`)
+
+      // Get all blocks in workflow to find children
+      const allBlocks = await tx
+        .select({
+          id: workflowBlocks.id,
+          locked: workflowBlocks.locked,
+          type: workflowBlocks.type,
+          data: workflowBlocks.data,
+        })
+        .from(workflowBlocks)
+        .where(eq(workflowBlocks.workflowId, workflowId))
+
+      type LockedBlockRecord = (typeof allBlocks)[number]
+      const blocksById: Record<string, LockedBlockRecord> = Object.fromEntries(
+        allBlocks.map((b: LockedBlockRecord) => [b.id, b])
+      )
+      const blocksToToggle = new Set<string>()
+
+      // Collect all blocks to toggle including children of containers
+      for (const id of blockIds) {
+        const block = blocksById[id]
+        if (!block) continue
+
+        blocksToToggle.add(id)
+
+        // If it's a loop or parallel, also include all children
+        if (block.type === 'loop' || block.type === 'parallel') {
+          for (const b of allBlocks) {
+            const parentId = (b.data as Record<string, unknown> | null)?.parentId
+            if (parentId === id) {
+              blocksToToggle.add(b.id)
+            }
+          }
+        }
+      }
+
+      // Determine target locked state based on first toggleable block
+      if (blocksToToggle.size === 0) break
+      const firstToggleableId = Array.from(blocksToToggle)[0]
+      const firstBlock = blocksById[firstToggleableId]
+      if (!firstBlock) break
+      const targetLocked = !firstBlock.locked
+
+      // Update all affected blocks
+      for (const blockId of blocksToToggle) {
+        await tx
+          .update(workflowBlocks)
+          .set({
+            locked: targetLocked,
+            updatedAt: new Date(),
+          })
+          .where(and(eq(workflowBlocks.id, blockId), eq(workflowBlocks.workflowId, workflowId)))
+      }
+
+      logger.debug(`Batch toggled locked for ${blocksToToggle.size} blocks`)
       break
     }
 
@@ -795,19 +991,54 @@ async function handleBlocksOperationTx(
 
       logger.info(`Batch updating parent for ${updates.length} blocks in workflow ${workflowId}`)
 
+      // Fetch all blocks to check lock status
+      const allBlocks = await tx
+        .select({
+          id: workflowBlocks.id,
+          locked: workflowBlocks.locked,
+          data: workflowBlocks.data,
+        })
+        .from(workflowBlocks)
+        .where(eq(workflowBlocks.workflowId, workflowId))
+
+      type ParentBlockRecord = (typeof allBlocks)[number]
+      const blocksById: Record<string, ParentBlockRecord> = Object.fromEntries(
+        allBlocks.map((b: ParentBlockRecord) => [b.id, b])
+      )
+
+      // Helper to check if a block is protected (locked or inside locked parent)
+      const isProtected = (blockId: string): boolean => {
+        const block = blocksById[blockId]
+        if (!block) return false
+        if (block.locked) return true
+        const currentParentId = (block.data as Record<string, unknown> | null)?.parentId as
+          | string
+          | undefined
+        if (currentParentId && blocksById[currentParentId]?.locked) return true
+        return false
+      }
+
       for (const update of updates) {
         const { id, parentId, position } = update
         if (!id) continue
 
+        // Skip protected blocks (locked or inside locked container)
+        if (isProtected(id)) {
+          logger.info(`Skipping block ${id} parent update - block is protected`)
+          continue
+        }
+
+        // Skip if trying to move into a locked container
+        if (parentId && blocksById[parentId]?.locked) {
+          logger.info(`Skipping block ${id} parent update - target parent ${parentId} is locked`)
+          continue
+        }
+
         // Fetch current parent to update subflow node lists
-        const [existing] = await tx
-          .select({
-            id: workflowBlocks.id,
-            parentId: sql<string | null>`${workflowBlocks.data}->>'parentId'`,
-          })
-          .from(workflowBlocks)
-          .where(and(eq(workflowBlocks.id, id), eq(workflowBlocks.workflowId, workflowId)))
-          .limit(1)
+        const existing = blocksById[id]
+        const existingParentId = (existing?.data as Record<string, unknown> | null)?.parentId as
+          | string
+          | undefined
 
         if (!existing) {
           logger.warn(`Block ${id} not found for batch-update-parent`)
@@ -852,8 +1083,8 @@ async function handleBlocksOperationTx(
           await updateSubflowNodeList(tx, workflowId, parentId)
         }
         // If the block had a previous parent, update that parent's node list as well
-        if (existing?.parentId && existing.parentId !== parentId) {
-          await updateSubflowNodeList(tx, workflowId, existing.parentId)
+        if (existingParentId && existingParentId !== parentId) {
+          await updateSubflowNodeList(tx, workflowId, existingParentId)
         }
       }
 
@@ -1198,6 +1429,7 @@ async function handleWorkflowOperationTx(
           advancedMode: block.advancedMode ?? false,
           triggerMode: block.triggerMode ?? false,
           height: block.height || 0,
+          locked: block.locked ?? false,
         }))
 
         await tx.insert(workflowBlocks).values(blockValues)

apps/sim/socket/middleware/permissions.test.ts

@@ -214,6 +214,12 @@ describe('checkRolePermission', () => {
         readAllowed: false,
       },
       { operation: 'toggle-handles', adminAllowed: true, writeAllowed: true, readAllowed: false },
+      {
+        operation: 'batch-toggle-locked',
+        adminAllowed: true,
+        writeAllowed: false, // Admin-only operation
+        readAllowed: false,
+      },
       {
         operation: 'batch-update-positions',
         adminAllowed: true,

apps/sim/socket/middleware/permissions.ts

@@ -14,7 +14,10 @@ import {
 
 const logger = createLogger('SocketPermissions')
 
-// All write operations (admin and write roles have same permissions)
+// Admin-only operations (require admin role)
+const ADMIN_ONLY_OPERATIONS: string[] = [BLOCKS_OPERATIONS.BATCH_TOGGLE_LOCKED]
+
+// Write operations (admin and write roles both have these permissions)
 const WRITE_OPERATIONS: string[] = [
   // Block operations
   BLOCK_OPERATIONS.UPDATE_POSITION,
@@ -51,7 +54,7 @@ const READ_OPERATIONS: string[] = [
 
 // Define operation permissions based on role
 const ROLE_PERMISSIONS: Record<string, string[]> = {
-  admin: WRITE_OPERATIONS,
+  admin: [...ADMIN_ONLY_OPERATIONS, ...WRITE_OPERATIONS],
   write: WRITE_OPERATIONS,
   read: READ_OPERATIONS,
 }

apps/sim/socket/validation/schemas.ts

@@ -208,6 +208,17 @@ export const BatchToggleHandlesSchema = z.object({
   operationId: z.string().optional(),
 })
 
+export const BatchToggleLockedSchema = z.object({
+  operation: z.literal(BLOCKS_OPERATIONS.BATCH_TOGGLE_LOCKED),
+  target: z.literal(OPERATION_TARGETS.BLOCKS),
+  payload: z.object({
+    blockIds: z.array(z.string()),
+    previousStates: z.record(z.boolean()),
+  }),
+  timestamp: z.number(),
+  operationId: z.string().optional(),
+})
+
 export const BatchUpdateParentSchema = z.object({
   operation: z.literal(BLOCKS_OPERATIONS.BATCH_UPDATE_PARENT),
   target: z.literal(OPERATION_TARGETS.BLOCKS),
@@ -231,6 +242,7 @@ export const WorkflowOperationSchema = z.union([
   BatchRemoveBlocksSchema,
   BatchToggleEnabledSchema,
   BatchToggleHandlesSchema,
+  BatchToggleLockedSchema,
   BatchUpdateParentSchema,
   EdgeOperationSchema,
   BatchAddEdgesSchema,

apps/sim/stores/undo-redo/types.ts

@@ -97,6 +97,14 @@ export interface BatchToggleHandlesOperation extends BaseOperation {
   }
 }
 
+export interface BatchToggleLockedOperation extends BaseOperation {
+  type: typeof UNDO_REDO_OPERATIONS.BATCH_TOGGLE_LOCKED
+  data: {
+    blockIds: string[]
+    previousStates: Record<string, boolean>
+  }
+}
+
 export interface ApplyDiffOperation extends BaseOperation {
   type: typeof UNDO_REDO_OPERATIONS.APPLY_DIFF
   data: {
@@ -136,6 +144,7 @@ export type Operation =
   | BatchUpdateParentOperation
   | BatchToggleEnabledOperation
   | BatchToggleHandlesOperation
+  | BatchToggleLockedOperation
   | ApplyDiffOperation
   | AcceptDiffOperation
   | RejectDiffOperation

apps/sim/stores/undo-redo/utils.ts

@@ -167,6 +167,15 @@ export function createInverseOperation(operation: Operation): Operation {
         },
       }
 
+    case UNDO_REDO_OPERATIONS.BATCH_TOGGLE_LOCKED:
+      return {
+        ...operation,
+        data: {
+          blockIds: operation.data.blockIds,
+          previousStates: operation.data.previousStates,
+        },
+      }
+
     default: {
       const exhaustiveCheck: never = operation
       throw new Error(`Unhandled operation type: ${(exhaustiveCheck as Operation).type}`)

apps/sim/stores/workflows/utils.test.ts

@@ -432,4 +432,104 @@ describe('regenerateBlockIds', () => {
     expect(duplicatedBlock.position).toEqual({ x: 280, y: 70 })
     expect(duplicatedBlock.data?.parentId).toBe(loopId)
   })
+
+  it('should unlock pasted block when source is locked', () => {
+    const blockId = 'block-1'
+
+    const blocksToCopy = {
+      [blockId]: createAgentBlock({
+        id: blockId,
+        name: 'Locked Agent',
+        position: { x: 100, y: 50 },
+        locked: true,
+      }),
+    }
+
+    const result = regenerateBlockIds(
+      blocksToCopy,
+      [],
+      {},
+      {},
+      {},
+      positionOffset,
+      {},
+      getUniqueBlockName
+    )
+
+    const newBlocks = Object.values(result.blocks)
+    expect(newBlocks).toHaveLength(1)
+
+    // Pasted blocks are always unlocked so users can edit them
+    const pastedBlock = newBlocks[0]
+    expect(pastedBlock.locked).toBe(false)
+  })
+
+  it('should keep pasted block unlocked when source is unlocked', () => {
+    const blockId = 'block-1'
+
+    const blocksToCopy = {
+      [blockId]: createAgentBlock({
+        id: blockId,
+        name: 'Unlocked Agent',
+        position: { x: 100, y: 50 },
+        locked: false,
+      }),
+    }
+
+    const result = regenerateBlockIds(
+      blocksToCopy,
+      [],
+      {},
+      {},
+      {},
+      positionOffset,
+      {},
+      getUniqueBlockName
+    )
+
+    const newBlocks = Object.values(result.blocks)
+    expect(newBlocks).toHaveLength(1)
+
+    const pastedBlock = newBlocks[0]
+    expect(pastedBlock.locked).toBe(false)
+  })
+
+  it('should unlock all pasted blocks regardless of source locked state', () => {
+    const lockedId = 'locked-1'
+    const unlockedId = 'unlocked-1'
+
+    const blocksToCopy = {
+      [lockedId]: createAgentBlock({
+        id: lockedId,
+        name: 'Originally Locked Agent',
+        position: { x: 100, y: 50 },
+        locked: true,
+      }),
+      [unlockedId]: createFunctionBlock({
+        id: unlockedId,
+        name: 'Originally Unlocked Function',
+        position: { x: 200, y: 50 },
+        locked: false,
+      }),
+    }
+
+    const result = regenerateBlockIds(
+      blocksToCopy,
+      [],
+      {},
+      {},
+      {},
+      positionOffset,
+      {},
+      getUniqueBlockName
+    )
+
+    const newBlocks = Object.values(result.blocks)
+    expect(newBlocks).toHaveLength(2)
+
+    // All pasted blocks should be unlocked so users can edit them
+    for (const block of newBlocks) {
+      expect(block.locked).toBe(false)
+    }
+  })
 })

apps/sim/stores/workflows/utils.ts

@@ -203,6 +203,7 @@ export function prepareBlockState(options: PrepareBlockStateOptions): BlockState
     advancedMode: false,
     triggerMode,
     height: 0,
+    locked: false,
   }
 }
 
@@ -481,6 +482,8 @@ export function regenerateBlockIds(
       position: newPosition,
       // Temporarily keep data as-is, we'll fix parentId in second pass
       data: block.data ? { ...block.data } : block.data,
+      // Duplicated blocks are always unlocked so users can edit them
+      locked: false,
     }
 
     newBlocks[newId] = newBlock
@@ -508,15 +511,15 @@ export function regenerateBlockIds(
           parentId: newParentId,
           extent: 'parent',
         }
-      } else if (existingBlockNames[oldParentId]) {
-        // Parent exists in existing workflow - keep original parentId (block stays in same subflow)
+      } else if (existingBlockNames[oldParentId] && !existingBlockNames[oldParentId].locked) {
+        // Parent exists in existing workflow and is not locked - keep original parentId
         block.data = {
           ...block.data,
           parentId: oldParentId,
           extent: 'parent',
         }
       } else {
-        // Parent doesn't exist anywhere - clear the relationship
+        // Parent doesn't exist anywhere OR parent is locked - clear the relationship
         block.data = { ...block.data, parentId: undefined, extent: undefined }
       }
     }

apps/sim/stores/workflows/workflow/store.test.ts

@@ -1144,6 +1144,223 @@ describe('workflow store', () => {
     })
   })
 
+  describe('batchToggleLocked', () => {
+    it('should toggle block locked state', () => {
+      const { batchToggleLocked } = useWorkflowStore.getState()
+
+      addBlock('block-1', 'function', 'Test', { x: 0, y: 0 })
+
+      // Initial state is undefined (falsy)
+      expect(useWorkflowStore.getState().blocks['block-1'].locked).toBeFalsy()
+
+      batchToggleLocked(['block-1'])
+      expect(useWorkflowStore.getState().blocks['block-1'].locked).toBe(true)
+
+      batchToggleLocked(['block-1'])
+      expect(useWorkflowStore.getState().blocks['block-1'].locked).toBe(false)
+    })
+
+    it('should cascade lock to children when locking a loop', () => {
+      const { batchToggleLocked } = useWorkflowStore.getState()
+
+      addBlock('loop-1', 'loop', 'My Loop', { x: 0, y: 0 }, { loopType: 'for', count: 3 })
+      addBlock(
+        'child-1',
+        'function',
+        'Child',
+        { x: 50, y: 50 },
+        { parentId: 'loop-1' },
+        'loop-1',
+        'parent'
+      )
+
+      batchToggleLocked(['loop-1'])
+
+      const { blocks } = useWorkflowStore.getState()
+      expect(blocks['loop-1'].locked).toBe(true)
+      expect(blocks['child-1'].locked).toBe(true)
+    })
+
+    it('should cascade unlock to children when unlocking a parallel', () => {
+      const { batchToggleLocked } = useWorkflowStore.getState()
+
+      addBlock('parallel-1', 'parallel', 'My Parallel', { x: 0, y: 0 }, { count: 3 })
+      addBlock(
+        'child-1',
+        'function',
+        'Child',
+        { x: 50, y: 50 },
+        { parentId: 'parallel-1' },
+        'parallel-1',
+        'parent'
+      )
+
+      // Lock first
+      batchToggleLocked(['parallel-1'])
+      expect(useWorkflowStore.getState().blocks['child-1'].locked).toBe(true)
+
+      // Unlock
+      batchToggleLocked(['parallel-1'])
+
+      const { blocks } = useWorkflowStore.getState()
+      expect(blocks['parallel-1'].locked).toBe(false)
+      expect(blocks['child-1'].locked).toBe(false)
+    })
+
+    it('should toggle multiple blocks at once', () => {
+      const { batchToggleLocked } = useWorkflowStore.getState()
+
+      addBlock('block-1', 'function', 'Test 1', { x: 0, y: 0 })
+      addBlock('block-2', 'function', 'Test 2', { x: 100, y: 0 })
+
+      batchToggleLocked(['block-1', 'block-2'])
+
+      const { blocks } = useWorkflowStore.getState()
+      expect(blocks['block-1'].locked).toBe(true)
+      expect(blocks['block-2'].locked).toBe(true)
+    })
+  })
+
+  describe('setBlockLocked', () => {
+    it('should set block locked state', () => {
+      const { setBlockLocked } = useWorkflowStore.getState()
+
+      addBlock('block-1', 'function', 'Test', { x: 0, y: 0 })
+
+      setBlockLocked('block-1', true)
+      expect(useWorkflowStore.getState().blocks['block-1'].locked).toBe(true)
+
+      setBlockLocked('block-1', false)
+      expect(useWorkflowStore.getState().blocks['block-1'].locked).toBe(false)
+    })
+
+    it('should not update if locked state is already the target value', () => {
+      const { setBlockLocked } = useWorkflowStore.getState()
+
+      addBlock('block-1', 'function', 'Test', { x: 0, y: 0 })
+
+      // First set to true
+      setBlockLocked('block-1', true)
+      expect(useWorkflowStore.getState().blocks['block-1'].locked).toBe(true)
+
+      // Setting to true again should still be true
+      setBlockLocked('block-1', true)
+      expect(useWorkflowStore.getState().blocks['block-1'].locked).toBe(true)
+    })
+  })
+
+  describe('duplicateBlock with locked', () => {
+    it('should unlock duplicate when duplicating a locked block', () => {
+      const { setBlockLocked, duplicateBlock } = useWorkflowStore.getState()
+
+      addBlock('original', 'agent', 'Original Agent', { x: 0, y: 0 })
+      setBlockLocked('original', true)
+
+      expect(useWorkflowStore.getState().blocks.original.locked).toBe(true)
+
+      duplicateBlock('original')
+
+      const { blocks } = useWorkflowStore.getState()
+      const blockIds = Object.keys(blocks)
+
+      expect(blockIds.length).toBe(2)
+
+      const duplicatedId = blockIds.find((id) => id !== 'original')
+      expect(duplicatedId).toBeDefined()
+
+      if (duplicatedId) {
+        // Original should still be locked
+        expect(blocks.original.locked).toBe(true)
+        // Duplicate should be unlocked so users can edit it
+        expect(blocks[duplicatedId].locked).toBe(false)
+      }
+    })
+
+    it('should create unlocked duplicate when duplicating an unlocked block', () => {
+      const { duplicateBlock } = useWorkflowStore.getState()
+
+      addBlock('original', 'agent', 'Original Agent', { x: 0, y: 0 })
+
+      duplicateBlock('original')
+
+      const { blocks } = useWorkflowStore.getState()
+      const blockIds = Object.keys(blocks)
+      const duplicatedId = blockIds.find((id) => id !== 'original')
+
+      if (duplicatedId) {
+        expect(blocks[duplicatedId].locked).toBeFalsy()
+      }
+    })
+
+    it('should place duplicate outside locked container when duplicating block inside locked loop', () => {
+      const { batchToggleLocked, duplicateBlock } = useWorkflowStore.getState()
+
+      // Create a loop with a child block
+      addBlock('loop-1', 'loop', 'My Loop', { x: 0, y: 0 }, { loopType: 'for', count: 3 })
+      addBlock(
+        'child-1',
+        'function',
+        'Child',
+        { x: 50, y: 50 },
+        { parentId: 'loop-1' },
+        'loop-1',
+        'parent'
+      )
+
+      // Lock the loop (which cascades to the child)
+      batchToggleLocked(['loop-1'])
+      expect(useWorkflowStore.getState().blocks['child-1'].locked).toBe(true)
+
+      // Duplicate the child block
+      duplicateBlock('child-1')
+
+      const { blocks } = useWorkflowStore.getState()
+      const blockIds = Object.keys(blocks)
+
+      expect(blockIds.length).toBe(3) // loop, original child, duplicate
+
+      const duplicatedId = blockIds.find((id) => id !== 'loop-1' && id !== 'child-1')
+      expect(duplicatedId).toBeDefined()
+
+      if (duplicatedId) {
+        // Duplicate should be unlocked
+        expect(blocks[duplicatedId].locked).toBe(false)
+        // Duplicate should NOT have a parentId (placed outside the locked container)
+        expect(blocks[duplicatedId].data?.parentId).toBeUndefined()
+        // Original should still be inside the loop
+        expect(blocks['child-1'].data?.parentId).toBe('loop-1')
+      }
+    })
+
+    it('should keep duplicate inside unlocked container when duplicating block inside unlocked loop', () => {
+      const { duplicateBlock } = useWorkflowStore.getState()
+
+      // Create a loop with a child block (not locked)
+      addBlock('loop-1', 'loop', 'My Loop', { x: 0, y: 0 }, { loopType: 'for', count: 3 })
+      addBlock(
+        'child-1',
+        'function',
+        'Child',
+        { x: 50, y: 50 },
+        { parentId: 'loop-1' },
+        'loop-1',
+        'parent'
+      )
+
+      // Duplicate the child block (loop is NOT locked)
+      duplicateBlock('child-1')
+
+      const { blocks } = useWorkflowStore.getState()
+      const blockIds = Object.keys(blocks)
+      const duplicatedId = blockIds.find((id) => id !== 'loop-1' && id !== 'child-1')
+
+      if (duplicatedId) {
+        // Duplicate should still be inside the loop since it's not locked
+        expect(blocks[duplicatedId].data?.parentId).toBe('loop-1')
+      }
+    })
+  })
+
   describe('updateBlockName', () => {
     beforeEach(() => {
       useWorkflowStore.setState({

apps/sim/stores/workflows/workflow/store.ts

@@ -207,6 +207,7 @@ export const useWorkflowStore = create<WorkflowStore>()(
           triggerMode?: boolean
           height?: number
           data?: Record<string, any>
+          locked?: boolean
         }>,
         edges?: Edge[],
         subBlockValues?: Record<string, Record<string, unknown>>,
@@ -231,6 +232,7 @@ export const useWorkflowStore = create<WorkflowStore>()(
             triggerMode: block.triggerMode ?? false,
             height: block.height ?? 0,
             data: block.data,
+            locked: block.locked ?? false,
           }
         }
 
@@ -365,24 +367,69 @@ export const useWorkflowStore = create<WorkflowStore>()(
       },
 
       batchToggleEnabled: (ids: string[]) => {
-        const newBlocks = { ...get().blocks }
+        if (ids.length === 0) return
+
+        const currentBlocks = get().blocks
+        const newBlocks = { ...currentBlocks }
+        const blocksToToggle = new Set<string>()
+
+        // For each ID, collect blocks to toggle (skip locked blocks entirely)
+        // If it's a container, also include non-locked children
         for (const id of ids) {
-          if (newBlocks[id]) {
-            newBlocks[id] = { ...newBlocks[id], enabled: !newBlocks[id].enabled }
+          const block = currentBlocks[id]
+          if (!block) continue
+
+          // Skip locked blocks entirely (including their children)
+          if (block.locked) continue
+
+          blocksToToggle.add(id)
+
+          // If it's a loop or parallel, also include non-locked children
+          if (block.type === 'loop' || block.type === 'parallel') {
+            Object.entries(currentBlocks).forEach(([blockId, b]) => {
+              if (b.data?.parentId === id && !b.locked) {
+                blocksToToggle.add(blockId)
+              }
+            })
           }
         }
+
+        // If no blocks can be toggled, exit early
+        if (blocksToToggle.size === 0) return
+
+        // Determine target enabled state based on first toggleable block
+        const firstToggleableId = Array.from(blocksToToggle)[0]
+        const firstBlock = currentBlocks[firstToggleableId]
+        const targetEnabled = !firstBlock.enabled
+
+        // Apply the enabled state to all toggleable blocks
+        for (const blockId of blocksToToggle) {
+          newBlocks[blockId] = { ...newBlocks[blockId], enabled: targetEnabled }
+        }
+
         set({ blocks: newBlocks, edges: [...get().edges] })
         get().updateLastSaved()
       },
 
       batchToggleHandles: (ids: string[]) => {
-        const newBlocks = { ...get().blocks }
+        const currentBlocks = get().blocks
+        const newBlocks = { ...currentBlocks }
+
+        // Helper to check if a block is protected (locked or inside locked parent)
+        const isProtected = (blockId: string): boolean => {
+          const block = currentBlocks[blockId]
+          if (!block) return false
+          if (block.locked) return true
+          const parentId = block.data?.parentId
+          if (parentId && currentBlocks[parentId]?.locked) return true
+          return false
+        }
+
         for (const id of ids) {
-          if (newBlocks[id]) {
-            newBlocks[id] = {
-              ...newBlocks[id],
-              horizontalHandles: !newBlocks[id].horizontalHandles,
-            }
+          if (!newBlocks[id] || isProtected(id)) continue
+          newBlocks[id] = {
+            ...newBlocks[id],
+            horizontalHandles: !newBlocks[id].horizontalHandles,
           }
         }
         set({ blocks: newBlocks, edges: [...get().edges] })
@@ -527,9 +574,33 @@ export const useWorkflowStore = create<WorkflowStore>()(
         if (!block) return
 
         const newId = crypto.randomUUID()
-        const offsetPosition = {
-          x: block.position.x + DEFAULT_DUPLICATE_OFFSET.x,
-          y: block.position.y + DEFAULT_DUPLICATE_OFFSET.y,
+
+        // Check if block is inside a locked container - if so, place duplicate outside
+        const parentId = block.data?.parentId
+        const parentBlock = parentId ? get().blocks[parentId] : undefined
+        const isParentLocked = parentBlock?.locked ?? false
+
+        // If parent is locked, calculate position outside the container
+        let offsetPosition: Position
+        const newData = block.data ? { ...block.data } : undefined
+
+        if (isParentLocked && parentBlock) {
+          // Place duplicate outside the locked container (to the right of it)
+          const containerWidth = parentBlock.data?.width ?? 400
+          offsetPosition = {
+            x: parentBlock.position.x + containerWidth + 50,
+            y: parentBlock.position.y,
+          }
+          // Remove parent relationship since we're placing outside
+          if (newData) {
+            newData.parentId = undefined
+            newData.extent = undefined
+          }
+        } else {
+          offsetPosition = {
+            x: block.position.x + DEFAULT_DUPLICATE_OFFSET.x,
+            y: block.position.y + DEFAULT_DUPLICATE_OFFSET.y,
+          }
         }
 
         const newName = getUniqueBlockName(block.name, get().blocks)
@@ -557,6 +628,8 @@ export const useWorkflowStore = create<WorkflowStore>()(
               name: newName,
               position: offsetPosition,
               subBlocks: newSubBlocks,
+              locked: false,
+              data: newData,
             },
           },
           edges: [...get().edges],
@@ -1164,6 +1237,70 @@ export const useWorkflowStore = create<WorkflowStore>()(
       getDragStartPosition: () => {
         return get().dragStartPosition || null
       },
+
+      setBlockLocked: (id: string, locked: boolean) => {
+        const block = get().blocks[id]
+        if (!block || block.locked === locked) return
+
+        const newState = {
+          blocks: {
+            ...get().blocks,
+            [id]: {
+              ...block,
+              locked,
+            },
+          },
+          edges: [...get().edges],
+          loops: { ...get().loops },
+          parallels: { ...get().parallels },
+        }
+
+        set(newState)
+        get().updateLastSaved()
+      },
+
+      batchToggleLocked: (ids: string[]) => {
+        if (ids.length === 0) return
+
+        const currentBlocks = get().blocks
+        const newBlocks = { ...currentBlocks }
+        const blocksToToggle = new Set<string>()
+
+        // For each ID, collect blocks to toggle
+        // If it's a container, also include all children
+        for (const id of ids) {
+          const block = currentBlocks[id]
+          if (!block) continue
+
+          blocksToToggle.add(id)
+
+          // If it's a loop or parallel, also include all children
+          if (block.type === 'loop' || block.type === 'parallel') {
+            Object.entries(currentBlocks).forEach(([blockId, b]) => {
+              if (b.data?.parentId === id) {
+                blocksToToggle.add(blockId)
+              }
+            })
+          }
+        }
+
+        // If no blocks found, exit early
+        if (blocksToToggle.size === 0) return
+
+        // Determine target locked state based on first block in original ids
+        const firstBlock = currentBlocks[ids[0]]
+        if (!firstBlock) return
+
+        const targetLocked = !firstBlock.locked
+
+        // Apply the locked state to all blocks
+        for (const blockId of blocksToToggle) {
+          newBlocks[blockId] = { ...newBlocks[blockId], locked: targetLocked }
+        }
+
+        set({ blocks: newBlocks, edges: [...get().edges] })
+        get().updateLastSaved()
+      },
     }),
     { name: 'workflow-store' }
   )

apps/sim/stores/workflows/workflow/types.ts

@@ -87,6 +87,7 @@ export interface BlockState {
   triggerMode?: boolean
   data?: BlockData
   layout?: BlockLayoutState
+  locked?: boolean
 }
 
 export interface SubBlockState {
@@ -131,6 +132,7 @@ export interface Loop {
   whileCondition?: string // JS expression that evaluates to boolean (for while loops)
   doWhileCondition?: string // JS expression that evaluates to boolean (for do-while loops)
   enabled: boolean
+  locked?: boolean
 }
 
 export interface Parallel {
@@ -140,6 +142,7 @@ export interface Parallel {
   count?: number // Number of parallel executions for count-based parallel
   parallelType?: 'count' | 'collection' // Explicit parallel type to avoid inference bugs
   enabled: boolean
+  locked?: boolean
 }
 
 export interface Variable {
@@ -233,6 +236,8 @@ export interface WorkflowActions {
     workflowState: WorkflowState,
     options?: { updateLastSaved?: boolean }
   ) => void
+  setBlockLocked: (id: string, locked: boolean) => void
+  batchToggleLocked: (ids: string[]) => void
 }
 
 export type WorkflowStore = WorkflowState & WorkflowActions

packages/db/migrations/0150_flimsy_hemingway.sql

@@ -0,0 +1 @@
+ALTER TABLE "workflow_blocks" ADD COLUMN "locked" boolean DEFAULT false NOT NULL;

packages/db/migrations/meta/_journal.json

@@ -1044,6 +1044,13 @@
       "when": 1769656977701,
       "tag": "0149_next_cerise",
       "breakpoints": true
+    },
+    {
+      "idx": 150,
+      "version": "7",
+      "when": 1769897862156,
+      "tag": "0150_flimsy_hemingway",
+      "breakpoints": true
     }
   ]
 }

packages/db/schema.ts

@@ -189,6 +189,7 @@ export const workflowBlocks = pgTable(
     isWide: boolean('is_wide').notNull().default(false),
     advancedMode: boolean('advanced_mode').notNull().default(false),
     triggerMode: boolean('trigger_mode').notNull().default(false),
+    locked: boolean('locked').notNull().default(false),
     height: decimal('height').notNull().default('0'),
 
     subBlocks: jsonb('sub_blocks').notNull().default('{}'),

packages/testing/src/factories/block.factory.ts

@@ -21,6 +21,7 @@ export interface BlockFactoryOptions {
   triggerMode?: boolean
   data?: BlockData
   parentId?: string
+  locked?: boolean
 }
 
 /**
@@ -67,6 +68,7 @@ export function createBlock(options: BlockFactoryOptions = {}): any {
     height: options.height ?? 0,
     advancedMode: options.advancedMode ?? false,
     triggerMode: options.triggerMode ?? false,
+    locked: options.locked ?? false,
     data: Object.keys(data).length > 0 ? data : undefined,
     layout: {},
   }