simstudioai · icecrasher321 · Jan 14, 2026 · Jan 14, 2026 · Jan 14, 2026
diff --git a/apps/sim/hooks/use-collaborative-workflow.ts b/apps/sim/hooks/use-collaborative-workflow.ts
@@ -22,7 +22,7 @@ import { useUndoRedoStore } from '@/stores/undo-redo'
 import { useWorkflowDiffStore } from '@/stores/workflow-diff/store'
 import { useWorkflowRegistry } from '@/stores/workflows/registry/store'
 import { useSubBlockStore } from '@/stores/workflows/subblock/store'
-import { mergeSubblockState, normalizeName } from '@/stores/workflows/utils'
+import { filterNewEdges, mergeSubblockState, normalizeName } from '@/stores/workflows/utils'
 import { useWorkflowStore } from '@/stores/workflows/workflow/store'
 import type { BlockState, Loop, Parallel, Position } from '@/stores/workflows/workflow/types'
 
@@ -242,7 +242,10 @@ export function useCollaborativeWorkflow() {
             case EDGES_OPERATIONS.BATCH_ADD_EDGES: {
               const { edges } = payload
               if (Array.isArray(edges) && edges.length > 0) {
-                workflowStore.batchAddEdges(edges)
+                const newEdges = filterNewEdges(edges, workflowStore.edges)
+                if (newEdges.length > 0) {
+                  workflowStore.batchAddEdges(newEdges)
+                }
               }
               break
             }
@@ -976,23 +979,26 @@ export function useCollaborativeWorkflow() {
 
       if (edges.length === 0) return false
 
+      const newEdges = filterNewEdges(edges, workflowStore.edges)
+      if (newEdges.length === 0) return false
+
       const operationId = crypto.randomUUID()
 
       addToQueue({
         id: operationId,
         operation: {
           operation: EDGES_OPERATIONS.BATCH_ADD_EDGES,
           target: OPERATION_TARGETS.EDGES,
-          payload: { edges },
+          payload: { edges: newEdges },
         },
         workflowId: activeWorkflowId || '',
         userId: session?.user?.id || 'unknown',
       })
 
-      workflowStore.batchAddEdges(edges)
+      workflowStore.batchAddEdges(newEdges)
 
       if (!options?.skipUndoRedo) {
-        edges.forEach((edge) => undoRedo.recordAddEdge(edge.id))
+        newEdges.forEach((edge) => undoRedo.recordAddEdge(edge.id))
       }
 
       return true

diff --git a/apps/sim/stores/workflows/utils.ts b/apps/sim/stores/workflows/utils.ts
@@ -1,5 +1,19 @@
 import type { Edge } from 'reactflow'
 import { v4 as uuidv4 } from 'uuid'
+
+export function filterNewEdges(edgesToAdd: Edge[], currentEdges: Edge[]): Edge[] {
+  return edgesToAdd.filter((edge) => {
+    if (edge.source === edge.target) return false
+    return !currentEdges.some(
+      (e) =>
+        e.source === edge.source &&
+        e.sourceHandle === edge.sourceHandle &&
+        e.target === edge.target &&
+        e.targetHandle === edge.targetHandle
+    )
+  })
+}
+
 import { getBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
 import { getBlock } from '@/blocks'
 import { normalizeName } from '@/executor/constants'

diff --git a/apps/sim/stores/workflows/workflow/store.test.ts b/apps/sim/stores/workflows/workflow/store.test.ts
@@ -297,7 +297,7 @@ describe('workflow store', () => {
       expectEdgeConnects(edges, 'block-1', 'block-2')
     })
 
-    it('should not add duplicate edges', () => {
+    it('should not add duplicate connections', () => {
       const { addBlock, batchAddEdges } = useWorkflowStore.getState()
 
       addBlock('block-1', 'starter', 'Start', { x: 0, y: 0 })
@@ -309,17 +309,6 @@ describe('workflow store', () => {
       const state = useWorkflowStore.getState()
       expectEdgeCount(state, 1)
     })
-
-    it('should prevent self-referencing edges', () => {
-      const { addBlock, batchAddEdges } = useWorkflowStore.getState()
-
-      addBlock('block-1', 'function', 'Self', { x: 0, y: 0 })
-
-      batchAddEdges([{ id: 'e1', source: 'block-1', target: 'block-1' }])
-
-      const state = useWorkflowStore.getState()
-      expectEdgeCount(state, 0)
-    })
   })
 
   describe('batchRemoveEdges', () => {

diff --git a/apps/sim/stores/workflows/workflow/store.ts b/apps/sim/stores/workflows/workflow/store.ts
@@ -9,7 +9,12 @@ import { getBlock } from '@/blocks'
 import type { SubBlockConfig } from '@/blocks/types'
 import { useWorkflowRegistry } from '@/stores/workflows/registry/store'
 import { useSubBlockStore } from '@/stores/workflows/subblock/store'
-import { getUniqueBlockName, mergeSubblockState, normalizeName } from '@/stores/workflows/utils'
+import {
+  filterNewEdges,
+  getUniqueBlockName,
+  mergeSubblockState,
+  normalizeName,
+} from '@/stores/workflows/utils'
 import type {
   Position,
   SubBlockState,
@@ -496,29 +501,11 @@ export const useWorkflowStore = create<WorkflowStore>()(
 
       batchAddEdges: (edges: Edge[]) => {
         const currentEdges = get().edges
+        const filtered = filterNewEdges(edges, currentEdges)
         const newEdges = [...currentEdges]
-        const existingEdgeIds = new Set(currentEdges.map((e) => e.id))
-
-        for (const edge of edges) {
-          // Skip if edge ID already exists
-          if (existingEdgeIds.has(edge.id)) continue
-
-          // Skip self-referencing edges
-          if (edge.source === edge.target) continue
-
-          // Skip if identical connection already exists (same ports)
-          const connectionExists = newEdges.some(
-            (e) =>
-              e.source === edge.source &&
-              e.sourceHandle === edge.sourceHandle &&
-              e.target === edge.target &&
-              e.targetHandle === edge.targetHandle
-          )
-          if (connectionExists) continue
 
-          // Skip if would create a cycle
+        for (const edge of filtered) {
           if (wouldCreateCycle([...newEdges], edge.source, edge.target)) continue
-
           newEdges.push({
             id: edge.id || crypto.randomUUID(),
             source: edge.source,
@@ -528,7 +515,6 @@ export const useWorkflowStore = create<WorkflowStore>()(
             type: edge.type || 'default',
             data: edge.data || {},
           })
-          existingEdgeIds.add(edge.id)
         }
 
         const blocks = get().blocks