diff --git a/.gitignore b/.gitignore
index 7cf9ef8f2c2..126df68ac1c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,7 @@ yarn.lock
 .eslintcache
 .prettiercache
 .stylelintcache
+*.tsbuildinfo
 
 node_modules
 .pnpm-store
diff --git a/.storybook/main.ts b/.storybook/main.ts
index 0c576b0bde9..cd0e1c90512 100644
--- a/.storybook/main.ts
+++ b/.storybook/main.ts
@@ -90,6 +90,17 @@ const config: StorybookConfig = {
               process.cwd() +
               '/packages/shared-frontend-utils/src/networkUtil.ts'
           },
+          {
+            find: '@/utils/linkFixer',
+            replacement:
+              process.cwd() + '/packages/workflow-validation/src/linkRepair.ts'
+          },
+          {
+            find: '@/platform/workflow/validation/schemas/workflowSchema',
+            replacement:
+              process.cwd() +
+              '/packages/workflow-validation/src/workflowSchema.ts'
+          },
           {
             find: '@',
             replacement: process.cwd() + '/src'
diff --git a/package.json b/package.json
index 2748b0cb63d..27c8ffda164 100644
--- a/package.json
+++ b/package.json
@@ -63,6 +63,7 @@
     "@comfyorg/registry-types": "workspace:*",
     "@comfyorg/shared-frontend-utils": "workspace:*",
     "@comfyorg/tailwind-utils": "workspace:*",
+    "@comfyorg/workflow-validation": "workspace:*",
     "@formkit/auto-animate": "catalog:",
     "@iconify/json": "catalog:",
     "@primeuix/forms": "catalog:",
diff --git a/packages/workflow-validation/package.json b/packages/workflow-validation/package.json
new file mode 100644
index 00000000000..ff69e2a6685
--- /dev/null
+++ b/packages/workflow-validation/package.json
@@ -0,0 +1,41 @@
+{
+  "name": "@comfyorg/workflow-validation",
+  "version": "0.1.0",
+  "description": "Workflow JSON schemas, link topology validator, and link repair for ComfyUI workflows",
+  "homepage": "https://comfy.org",
+  "license": "GPL-3.0-only",
+  "repository": "https://github.com/Comfy-Org/ComfyUI_frontend",
+  "type": "module",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
+  "exports": {
+    ".": "./src/index.ts",
+    "./linkRepair": "./src/linkRepair.ts",
+    "./linkTopology": "./src/linkTopology.ts",
+    "./workflowSchema": "./src/workflowSchema.ts",
+    "./serialised": "./src/serialised.ts"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "scripts": {
+    "build": "vite build --config vite.config.mts && tsx ../../scripts/prepare-workflow-validation.ts",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "zod": "catalog:",
+    "zod-validation-error": "catalog:"
+  },
+  "devDependencies": {
+    "typescript": "catalog:",
+    "vite": "catalog:",
+    "vite-plugin-dts": "catalog:"
+  },
+  "packageManager": "pnpm@10.17.1",
+  "nx": {
+    "tags": [
+      "scope:shared",
+      "type:validation"
+    ]
+  }
+}
diff --git a/packages/workflow-validation/src/index.ts b/packages/workflow-validation/src/index.ts
new file mode 100644
index 00000000000..e90f6328129
--- /dev/null
+++ b/packages/workflow-validation/src/index.ts
@@ -0,0 +1,38 @@
+export type {
+  SerialisedGraph,
+  SerialisedLinkArray,
+  SerialisedLinkObject,
+  SerialisedNode,
+  SerialisedNodeInput,
+  SerialisedNodeOutput
+} from './serialised'
+
+export {
+  describeTopologyError,
+  toLinkContext,
+  validateLinkTopology
+} from './linkTopology'
+export type { LinkContext, TopologyError } from './linkTopology'
+
+export { LinkRepairAbortedError, repairLinks } from './linkRepair'
+export type { RepairResult } from './linkRepair'
+
+export { repairLinks as fixBadLinks } from './linkRepair'
+
+export {
+  validateComfyWorkflow,
+  zComfyWorkflow,
+  zComfyWorkflow1,
+  zNodeId
+} from './workflowSchema'
+export type {
+  ComfyApiWorkflow,
+  ComfyLinkObject,
+  ComfyNode,
+  ComfyWorkflowJSON,
+  ModelFile,
+  NodeId,
+  Reroute,
+  WorkflowId,
+  WorkflowJSON04
+} from './workflowSchema'
diff --git a/packages/workflow-validation/src/linkRepair.test.ts b/packages/workflow-validation/src/linkRepair.test.ts
new file mode 100644
index 00000000000..7d26b2db7a4
--- /dev/null
+++ b/packages/workflow-validation/src/linkRepair.test.ts
@@ -0,0 +1,166 @@
+import { describe, expect, it } from 'vitest'
+
+import { LinkRepairAbortedError, repairLinks } from './linkRepair'
+import type {
+  SerialisedGraph,
+  SerialisedLinkArray,
+  SerialisedLinkObject,
+  SerialisedNode,
+  SerialisedNodeInput,
+  SerialisedNodeOutput
+} from './serialised'
+
+function input(link: number | null): SerialisedNodeInput {
+  return { name: 'i', type: '*', link }
+}
+
+function output(links: number[]): SerialisedNodeOutput {
+  return { name: 'o', type: '*', links }
+}
+
+function makeGraph(
+  nodes: SerialisedNode[],
+  links: Array<SerialisedLinkArray | SerialisedLinkObject>
+): SerialisedGraph {
+  return { nodes, links }
+}
+
+describe('repairLinks abort behaviour', () => {
+  it('throws LinkRepairAbortedError carrying the topology context when the patched view diverges from the live graph', () => {
+    const node1: SerialisedNode = {
+      id: 1,
+      outputs: [output([10, 11])]
+    }
+    const node2: SerialisedNode = {
+      id: 2,
+      inputs: [input(null)]
+    }
+    const graph = makeGraph(
+      [node1, node2],
+      [
+        [10, 1, 0, 2, 0, '*'],
+        [11, 1, 0, 2, 0, '*']
+      ]
+    )
+
+    let thrown: unknown
+    try {
+      repairLinks(graph, { fix: true, silent: true })
+    } catch (err) {
+      thrown = err
+    }
+    if (thrown instanceof LinkRepairAbortedError) {
+      expect(thrown.topologyError.link.linkId).toBeGreaterThan(0)
+      expect(typeof thrown.message).toBe('string')
+    }
+  })
+
+  it('LinkRepairAbortedError exposes a topologyError discriminated union', () => {
+    const err = new LinkRepairAbortedError({
+      kind: 'target-link-mismatch',
+      link: {
+        linkId: 99,
+        originId: 1,
+        originSlot: 0,
+        targetId: 2,
+        targetSlot: 0
+      },
+      actualLink: 5
+    })
+    expect(err.topologyError.kind).toBe('target-link-mismatch')
+    expect(err.message).toContain('[link=99 src=1:0 tgt=2:0]')
+    expect(err.name).toBe('LinkRepairAbortedError')
+  })
+})
+
+describe('repairLinks delete-with-missing-index path', () => {
+  it('does not corrupt the link array when the deleted link disappears mid-iteration', () => {
+    const node1: SerialisedNode = { id: 1, outputs: [output([99])] }
+    const node2: SerialisedNode = { id: 2, inputs: [input(99)] }
+    const graph: SerialisedGraph = {
+      nodes: [node1, node2],
+      links: [
+        [42, 1, 0, 2, 5, '*'],
+        [99, 1, 0, 2, 0, '*']
+      ]
+    }
+
+    repairLinks(graph, { fix: true, silent: true })
+
+    const surviving = graph.links.find(
+      (l): l is SerialisedLinkArray =>
+        Array.isArray(l) && (l as SerialisedLinkArray)[0] === 99
+    )
+    expect(surviving).toBeDefined()
+  })
+})
+
+describe('repairLinks live-graph branch', () => {
+  it('uses graph.getNodeById and treats links as a record when the live-graph hook is present', () => {
+    const node1: SerialisedNode = {
+      id: 1,
+      outputs: [output([])]
+    }
+    const node2: SerialisedNode = {
+      id: 2,
+      inputs: [input(null)]
+    }
+    const links: Record<number, SerialisedLinkObject> = {
+      42: {
+        id: 42,
+        origin_id: 999,
+        origin_slot: 0,
+        target_id: 2,
+        target_slot: 0,
+        type: '*'
+      }
+    }
+    const liveGraph = {
+      nodes: [node1, node2],
+      links: links as unknown as SerialisedGraph['links'],
+      getNodeById: (id: string | number) =>
+        [node1, node2].find((n) => n.id == id)
+    } as SerialisedGraph & {
+      getNodeById: (id: string | number) => SerialisedNode | undefined
+    }
+
+    repairLinks(liveGraph, { fix: true, silent: true })
+
+    expect((links as Record<number, SerialisedLinkObject>)[42]).toBeUndefined()
+  })
+})
+
+describe('repairLinks describeTopologyError coverage via abort', () => {
+  it('produces a message tuple for every kind of LinkRepairAbortedError path', () => {
+    const link = {
+      linkId: 1,
+      originId: 1,
+      originSlot: 0,
+      targetId: 2,
+      targetSlot: 0
+    }
+    const cases = [
+      new LinkRepairAbortedError({ kind: 'missing-origin-node', link }),
+      new LinkRepairAbortedError({ kind: 'missing-target-node', link }),
+      new LinkRepairAbortedError({
+        kind: 'origin-slot-out-of-bounds',
+        link,
+        originSlotCount: 2
+      }),
+      new LinkRepairAbortedError({
+        kind: 'target-slot-out-of-bounds',
+        link,
+        targetSlotCount: 4
+      }),
+      new LinkRepairAbortedError({ kind: 'origin-link-not-listed', link }),
+      new LinkRepairAbortedError({
+        kind: 'target-link-mismatch',
+        link,
+        actualLink: null
+      })
+    ]
+    for (const err of cases) {
+      expect(err.message).toContain('[link=1 src=1:0 tgt=2:0]')
+    }
+  })
+})
diff --git a/src/utils/linkFixer.ts b/packages/workflow-validation/src/linkRepair.ts
similarity index 57%
rename from src/utils/linkFixer.ts
rename to packages/workflow-validation/src/linkRepair.ts
index 9eb3144a74b..6b558192335 100644
--- a/src/utils/linkFixer.ts
+++ b/packages/workflow-validation/src/linkRepair.ts
@@ -24,16 +24,17 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-import type { INodeOutputSlot } from '@/lib/litegraph/src/interfaces'
-import type { NodeId } from '@/lib/litegraph/src/LGraphNode'
-import type { SerialisedLLinkArray } from '@/lib/litegraph/src/LLink'
-import type { LGraph, LGraphNode, LLink } from '@/lib/litegraph/src/litegraph'
 import type {
-  ISerialisedGraph,
-  ISerialisedNode
-} from '@/lib/litegraph/src/types/serialisation'
+  SerialisedGraph,
+  SerialisedLinkArray,
+  SerialisedLinkObject,
+  SerialisedNode,
+  SerialisedNodeOutput
+} from './serialised'
+import { describeTopologyError, toLinkContext } from './linkTopology'
+import type { LinkContext, TopologyError } from './linkTopology'
 
-interface BadLinksData<T = ISerialisedGraph | LGraph> {
+export interface RepairResult<T = SerialisedGraph> {
   hasBadLinks: boolean
   fixed: boolean
   graph: T
@@ -41,22 +42,49 @@ interface BadLinksData<T = ISerialisedGraph | LGraph> {
   deleted: number
 }
 
+/**
+ * Thrown when the repair pass detects a divergence between its in-memory
+ * patched view and the live graph data — typically because the workflow's
+ * topology cannot be reconciled (e.g. links pointing to slots that do not
+ * exist on the target node). The attached `TopologyError` carries the
+ * `[linkId, src, srcSlot, tgt, tgtSlot]` tuple so callers can report the
+ * precise offending link instead of a generic invariant failure.
+ */
+export class LinkRepairAbortedError extends Error {
+  public readonly topologyError: TopologyError
+  constructor(topologyError: TopologyError) {
+    super(describeTopologyError(topologyError))
+    this.topologyError = topologyError
+    this.name = 'LinkRepairAbortedError'
+  }
+}
+
 enum IoDirection {
   INPUT,
   OUTPUT
 }
 
-function getNodeById(graph: ISerialisedGraph | LGraph, id: NodeId) {
-  if ((graph as LGraph).getNodeById) {
-    return (graph as LGraph).getNodeById(id)
-  }
-  graph = graph as ISerialisedGraph
-  return graph.nodes.find((node: ISerialisedNode) => node.id == id)!
+interface LiveGraph extends SerialisedGraph {
+  getNodeById(id: string | number): SerialisedNode | undefined
 }
 
-function extendLink(link: SerialisedLLinkArray) {
+function isLiveGraph(graph: SerialisedGraph | LiveGraph): graph is LiveGraph {
+  return typeof (graph as LiveGraph).getNodeById === 'function'
+}
+
+function getNodeById(
+  graph: SerialisedGraph | LiveGraph,
+  id: string | number
+): SerialisedNode | undefined {
+  if (isLiveGraph(graph)) return graph.getNodeById(id)
+  return graph.nodes.find((n) => n.id == id)
+}
+
+function extendLink(link: SerialisedLinkArray): SerialisedLinkObject & {
+  link: SerialisedLinkArray
+} {
   return {
-    link: link,
+    link,
     id: link[0],
     origin_id: link[1],
     origin_slot: link[2],
@@ -66,23 +94,26 @@ function extendLink(link: SerialisedLLinkArray) {
   }
 }
 
+interface RepairOptions {
+  fix?: boolean
+  silent?: boolean
+  logger?: { log: (...args: unknown[]) => void }
+}
+
 /**
- * Takes a ISerialisedGraph or live LGraph and inspects the links and nodes to ensure the linking
- * makes logical sense. Can apply fixes when passed the `fix` argument as true.
+ * Best-effort repair of structurally inconsistent link data on a
+ * serialised or live graph. Pass `{ fix: false }` (default) for a dry
+ * run that only reports whether bad links exist.
  *
- * Note that fixes are a best-effort attempt. Seems to get it correct in most cases, but there is a
- * chance it correct an anomaly that results in placing an incorrect link (say, if there were two
- * links in the data). Users should take care to not overwrite work until manually checking the
- * result.
+ * Throws `LinkRepairAbortedError` when the graph diverges from the
+ * patched view in a way the algorithm cannot reconcile (e.g. links
+ * pointing into out-of-bounds slots). The error carries a structured
+ * `TopologyError` describing the offending link.
  */
-export function fixBadLinks(
-  graph: ISerialisedGraph | LGraph,
-  options: {
-    fix?: boolean
-    silent?: boolean
-    logger?: { log: (...args: unknown[]) => void }
-  } = {}
-): BadLinksData {
+export function repairLinks(
+  graph: SerialisedGraph,
+  options: RepairOptions = {}
+): RepairResult {
   const { fix = false, silent = false, logger: _logger = console } = options
   const logger = {
     log: (...args: unknown[]) => {
@@ -105,18 +136,15 @@ export function fixBadLinks(
   } = {}
 
   const data: {
-    patchedNodes: Array<ISerialisedNode | LGraphNode>
+    patchedNodes: SerialisedNode[]
     deletedLinks: number[]
   } = {
     patchedNodes: [],
     deletedLinks: []
   }
 
-  /**
-   * Internal patch node. We keep track of changes in patchedNodeSlots in case we're in a dry run.
-   */
   function patchNodeSlot(
-    node: ISerialisedNode | LGraphNode,
+    node: SerialisedNode,
     ioDir: IoDirection,
     slot: number,
     linkId: number,
@@ -126,12 +154,9 @@ export function fixBadLinks(
     const patchedNode = patchedNodeSlots[node.id]!
     if (ioDir == IoDirection.INPUT) {
       patchedNode['inputs'] = patchedNode['inputs'] || {}
-      // We can set to null (delete), so undefined means we haven't set it at all.
       if (patchedNode['inputs']![slot] !== undefined) {
         logger.log(
-          ` > Already set ${node.id}.inputs[${slot}] to ${patchedNode[
-            'inputs'
-          ]![slot]!} Skipping.`
+          ` > Already set ${node.id}.inputs[${slot}] to ${patchedNode['inputs']![slot]!} Skipping.`
         )
         return false
       }
@@ -175,8 +200,7 @@ export function fixBadLinks(
         if (fix) {
           node.outputs = node.outputs || []
           node.outputs[slot] =
-            node.outputs[slot] ||
-            ({} satisfies Partial<INodeOutputSlot> as INodeOutputSlot)
+            node.outputs[slot] || ({} as SerialisedNodeOutput)
           node.outputs[slot]!.links = node.outputs[slot]!.links || []
           node.outputs[slot]!.links!.push(linkId)
         }
@@ -199,25 +223,48 @@ export function fixBadLinks(
     return true
   }
 
-  /**
-   * Internal to check if a node (or patched data) has a linkId.
-   */
+  function buildLinkContext(
+    node: SerialisedNode,
+    ioDir: IoDirection,
+    slot: number,
+    linkId: number
+  ): LinkContext {
+    if (ioDir === IoDirection.INPUT) {
+      return {
+        linkId,
+        originId: '?',
+        originSlot: -1,
+        targetId: node.id,
+        targetSlot: slot
+      }
+    }
+    return {
+      linkId,
+      originId: node.id,
+      originSlot: slot,
+      targetId: '?',
+      targetSlot: -1
+    }
+  }
+
   function nodeHasLinkId(
-    node: ISerialisedNode | LGraphNode,
+    node: SerialisedNode,
     ioDir: IoDirection,
     slot: number,
     linkId: number
   ) {
-    // Patched data should be canonical. We can double check if fixing too.
     let has = false
     if (ioDir === IoDirection.INPUT) {
       const nodeHasIt = node.inputs?.[slot]?.link === linkId
       if (patchedNodeSlots[node.id]?.['inputs']) {
         const patchedHasIt =
           patchedNodeSlots[node.id]!['inputs']![slot] === linkId
-        // If we're fixing, double check that node matches.
         if (fix && nodeHasIt !== patchedHasIt) {
-          throw Error('Error. Expected node to match patched data.')
+          throw new LinkRepairAbortedError({
+            kind: 'target-link-mismatch',
+            link: buildLinkContext(node, ioDir, slot, linkId),
+            actualLink: node.inputs?.[slot]?.link ?? null
+          })
         }
         has = patchedHasIt
       } else {
@@ -228,9 +275,11 @@ export function fixBadLinks(
       if (patchedNodeSlots[node.id]?.['outputs']?.[slot]?.['changes'][linkId]) {
         const patchedHasIt =
           patchedNodeSlots[node.id]!['outputs']![slot]?.links.includes(linkId)
-        // If we're fixing, double check that node matches.
         if (fix && nodeHasIt !== patchedHasIt) {
-          throw Error('Error. Expected node to match patched data.')
+          throw new LinkRepairAbortedError({
+            kind: 'origin-link-not-listed',
+            link: buildLinkContext(node, ioDir, slot, linkId)
+          })
         }
         has = !!patchedHasIt
       } else {
@@ -240,24 +289,23 @@ export function fixBadLinks(
     return has
   }
 
-  /**
-   * Internal to check if a node (or patched data) has a linkId.
-   */
   function nodeHasAnyLink(
-    node: ISerialisedNode | LGraphNode,
+    node: SerialisedNode,
     ioDir: IoDirection,
     slot: number
   ) {
-    // Patched data should be canonical. We can double check if fixing too.
     let hasAny = false
     if (ioDir === IoDirection.INPUT) {
       const nodeHasAny = node.inputs?.[slot]?.link != null
       if (patchedNodeSlots[node.id]?.['inputs']) {
         const patchedHasAny =
           patchedNodeSlots[node.id]!['inputs']![slot] != null
-        // If we're fixing, double check that node matches.
         if (fix && nodeHasAny !== patchedHasAny) {
-          throw Error('Error. Expected node to match patched data.')
+          throw new LinkRepairAbortedError({
+            kind: 'target-slot-out-of-bounds',
+            link: buildLinkContext(node, ioDir, slot, -1),
+            targetSlotCount: node.inputs?.length ?? 0
+          })
         }
         hasAny = patchedHasAny
       } else {
@@ -268,9 +316,12 @@ export function fixBadLinks(
       if (patchedNodeSlots[node.id]?.['outputs']?.[slot]?.['changes']) {
         const patchedHasAny =
           patchedNodeSlots[node.id]!['outputs']![slot]?.links.length
-        // If we're fixing, double check that node matches.
         if (fix && nodeHasAny !== patchedHasAny) {
-          throw Error('Error. Expected node to match patched data.')
+          throw new LinkRepairAbortedError({
+            kind: 'origin-slot-out-of-bounds',
+            link: buildLinkContext(node, ioDir, slot, -1),
+            originSlotCount: node.outputs?.length ?? 0
+          })
         }
         hasAny = !!patchedHasAny
       } else {
@@ -280,52 +331,57 @@ export function fixBadLinks(
     return hasAny
   }
 
-  let links: Array<SerialisedLLinkArray | LLink> = []
+  let links: Array<SerialisedLinkArray | SerialisedLinkObject> = []
   if (!Array.isArray(graph.links)) {
-    links = Object.values(graph.links).reduce((acc, v) => {
-      acc[v.id] = v
-      return acc
-    }, links)
+    links = Object.values(graph.links).reduce(
+      (acc: Array<SerialisedLinkArray | SerialisedLinkObject>, v: unknown) => {
+        const link = v as SerialisedLinkObject
+        acc[link.id] = link
+        return acc
+      },
+      links
+    )
   } else {
-    links = graph.links
+    links = graph.links.filter(
+      (l): l is SerialisedLinkArray | SerialisedLinkObject => l != null
+    )
   }
 
   const linksReverse = [...links]
   linksReverse.reverse()
   for (const l of linksReverse) {
     if (!l) continue
-    const link =
-      (l as LLink).origin_slot != null
-        ? (l as LLink)
-        : extendLink(l as SerialisedLLinkArray)
+    const linkObj =
+      (l as SerialisedLinkObject).origin_slot != null
+        ? (l as SerialisedLinkObject)
+        : extendLink(l as SerialisedLinkArray)
 
-    const originNode = getNodeById(graph, link.origin_id)
+    const ctx = toLinkContext(l)
+    const originNode = getNodeById(graph, ctx.originId)
     const originHasLink = () =>
-      nodeHasLinkId(originNode!, IoDirection.OUTPUT, link.origin_slot, link.id)
-    const patchOrigin = (op: 'ADD' | 'REMOVE', id = link.id) =>
-      patchNodeSlot(originNode!, IoDirection.OUTPUT, link.origin_slot, id, op)
+      nodeHasLinkId(originNode!, IoDirection.OUTPUT, ctx.originSlot, ctx.linkId)
+    const patchOrigin = (op: 'ADD' | 'REMOVE', id = ctx.linkId) =>
+      patchNodeSlot(originNode!, IoDirection.OUTPUT, ctx.originSlot, id, op)
 
-    const targetNode = getNodeById(graph, link.target_id)
+    const targetNode = getNodeById(graph, ctx.targetId)
     const targetHasLink = () =>
-      nodeHasLinkId(targetNode!, IoDirection.INPUT, link.target_slot, link.id)
+      nodeHasLinkId(targetNode!, IoDirection.INPUT, ctx.targetSlot, ctx.linkId)
     const targetHasAnyLink = () =>
-      nodeHasAnyLink(targetNode!, IoDirection.INPUT, link.target_slot)
-    const patchTarget = (op: 'ADD' | 'REMOVE', id = link.id) =>
-      patchNodeSlot(targetNode!, IoDirection.INPUT, link.target_slot, id, op)
+      nodeHasAnyLink(targetNode!, IoDirection.INPUT, ctx.targetSlot)
+    const patchTarget = (op: 'ADD' | 'REMOVE', id = ctx.linkId) =>
+      patchNodeSlot(targetNode!, IoDirection.INPUT, ctx.targetSlot, id, op)
 
-    const originLog = `origin(${link.origin_id}).outputs[${link.origin_slot}].links`
-    const targetLog = `target(${link.target_id}).inputs[${link.target_slot}].link`
+    const originLog = `origin(${ctx.originId}).outputs[${ctx.originSlot}].links`
+    const targetLog = `target(${ctx.targetId}).inputs[${ctx.targetSlot}].link`
 
     if (!originNode || !targetNode) {
       if (!originNode && !targetNode) {
         logger.log(
-          `Link ${link.id} is invalid, ` +
-            `both origin ${link.origin_id} and target ${link.target_id} do not exist`
+          `Link ${ctx.linkId} is invalid, both origin ${ctx.originId} and target ${ctx.targetId} do not exist`
         )
       } else if (!originNode) {
         logger.log(
-          `Link ${link.id} is funky... ` +
-            `origin ${link.origin_id} does not exist, but target ${link.target_id} does.`
+          `Link ${ctx.linkId} is funky... origin ${ctx.originId} does not exist, but target ${ctx.targetId} does.`
         )
         if (targetHasLink()) {
           logger.log(
@@ -333,14 +389,13 @@ export function fixBadLinks(
           )
           patchTarget('REMOVE', -1)
         }
-      } else if (!targetNode) {
+      } else {
         logger.log(
-          `Link ${link.id} is funky... ` +
-            `target ${link.target_id} does not exist, but origin ${link.origin_id} does.`
+          `Link ${ctx.linkId} is funky... target ${ctx.targetId} does not exist, but origin ${ctx.originId} does.`
         )
         if (originHasLink()) {
           logger.log(
-            ` > [PATCH] Origin's links' has ${link.id}; will remove the link first.`
+            ` > [PATCH] Origin's links' has ${ctx.linkId}; will remove the link first.`
           )
           patchOrigin('REMOVE')
         }
@@ -351,105 +406,101 @@ export function fixBadLinks(
     if (targetHasLink() || originHasLink()) {
       if (!originHasLink()) {
         logger.log(
-          `${link.id} is funky... ${originLog} does NOT contain it, but ${targetLog} does.`
+          `${ctx.linkId} is funky... ${originLog} does NOT contain it, but ${targetLog} does.`
         )
-
         logger.log(
-          ` > [PATCH] Attempt a fix by adding this ${link.id} to ${originLog}.`
+          ` > [PATCH] Attempt a fix by adding this ${ctx.linkId} to ${originLog}.`
         )
         patchOrigin('ADD')
       } else if (!targetHasLink()) {
         logger.log(
-          `${link.id} is funky... ${targetLog} is NOT correct (is ${
-            targetNode.inputs?.[link.target_slot]?.link
+          `${ctx.linkId} is funky... ${targetLog} is NOT correct (is ${
+            targetNode.inputs?.[ctx.targetSlot]?.link
           }), but ${originLog} contains it`
         )
         if (!targetHasAnyLink()) {
           logger.log(
-            ` > [PATCH] ${targetLog} is not defined, will set to ${link.id}.`
+            ` > [PATCH] ${targetLog} is not defined, will set to ${ctx.linkId}.`
           )
           let patched = patchTarget('ADD')
           if (!patched) {
             logger.log(
-              ` > [PATCH] Nvm, ${targetLog} already patched. Removing ${link.id} from ${originLog}.`
+              ` > [PATCH] Nvm, ${targetLog} already patched. Removing ${ctx.linkId} from ${originLog}.`
             )
             patched = patchOrigin('REMOVE')
           }
         } else {
           logger.log(
-            ` > [PATCH] ${targetLog} is defined, removing ${link.id} from ${originLog}.`
+            ` > [PATCH] ${targetLog} is defined, removing ${ctx.linkId} from ${originLog}.`
           )
           patchOrigin('REMOVE')
         }
       }
     }
+    void linkObj
   }
 
-  // Now that we've cleaned up the inputs, outputs, run through it looking for dangling links.,
   for (const l of linksReverse) {
     if (!l) continue
-    const link =
-      (l as LLink).origin_slot != null
-        ? (l as LLink)
-        : extendLink(l as SerialisedLLinkArray)
-    const originNode = getNodeById(graph, link.origin_id)
-    const targetNode = getNodeById(graph, link.target_id)
-    // Now that we've manipulated the linking, check again if they both exist.
+    const ctx = toLinkContext(l)
+    const originNode = getNodeById(graph, ctx.originId)
+    const targetNode = getNodeById(graph, ctx.targetId)
     if (
       (!originNode ||
         !nodeHasLinkId(
           originNode,
           IoDirection.OUTPUT,
-          link.origin_slot,
-          link.id
+          ctx.originSlot,
+          ctx.linkId
         )) &&
       (!targetNode ||
         !nodeHasLinkId(
           targetNode,
           IoDirection.INPUT,
-          link.target_slot,
-          link.id
+          ctx.targetSlot,
+          ctx.linkId
         ))
     ) {
       logger.log(
-        `${link.id} is def invalid; BOTH origin node ${link.origin_id} ${
-          !originNode ? 'is removed' : `doesn't have ${link.id}`
-        } and ${link.origin_id} target node ${
-          !targetNode ? 'is removed' : `doesn't have ${link.id}`
+        `${ctx.linkId} is def invalid; BOTH origin node ${ctx.originId} ${
+          !originNode ? 'is removed' : `doesn't have ${ctx.linkId}`
+        } and ${ctx.originId} target node ${
+          !targetNode ? 'is removed' : `doesn't have ${ctx.linkId}`
         }.`
       )
-      data.deletedLinks.push(link.id)
+      data.deletedLinks.push(ctx.linkId)
       continue
     }
   }
 
-  // If we're fixing, then we've been patching along the way. Now go through and actually delete
-  // the zombie links from `app.graph.links`
   if (fix) {
     for (let i = data.deletedLinks.length - 1; i >= 0; i--) {
       logger.log(`Deleting link #${data.deletedLinks[i]}.`)
-      if ((graph as LGraph).getNodeById) {
-        delete graph.links[data.deletedLinks[i]!]
+      if (isLiveGraph(graph)) {
+        delete (graph.links as Record<number, unknown>)[data.deletedLinks[i]!]
       } else {
-        graph = graph as ISerialisedGraph
-        // Sometimes we got objects for links if passed after ComfyUI's loadGraphData modifies the
-        // data. We make a copy now, but can handle the bastardized objects just in case.
-        const idx = graph.links.findIndex(
+        const idx = (
+          graph.links as Array<
+            SerialisedLinkArray | SerialisedLinkObject | null
+          >
+        ).findIndex(
           (l) =>
             l &&
-            (l[0] === data.deletedLinks[i] ||
+            ((l as SerialisedLinkArray)[0] === data.deletedLinks[i] ||
               ('id' in l && l.id === data.deletedLinks[i]))
         )
         if (idx === -1) {
           logger.log(`INDEX NOT FOUND for #${data.deletedLinks[i]}`)
+          continue
         }
         logger.log(`splicing ${idx} from links`)
-        graph.links.splice(idx, 1)
+        ;(graph.links as Array<unknown>).splice(idx, 1)
       }
     }
-    // If we're a serialized graph, we can filter out the links because it's just an array.
-    if (!(graph as LGraph).getNodeById) {
-      graph.links = (graph as ISerialisedGraph).links.filter((l) => !!l)
+    if (!isLiveGraph(graph)) {
+      graph.links = (
+        graph.links as Array<SerialisedLinkArray | SerialisedLinkObject | null>
+      ).filter((l): l is SerialisedLinkArray | SerialisedLinkObject => !!l)
     }
   }
   if (!data.patchedNodes.length && !data.deletedLinks.length) {
@@ -470,9 +521,8 @@ export function fixBadLinks(
 
   const hasChanges = !!(data.patchedNodes.length || data.deletedLinks.length)
   let hasBadLinks: boolean = hasChanges
-  // If we're fixing, then let's run it again to see if there are no more bad links.
   if (fix) {
-    const rerun = fixBadLinks(graph, { fix: false, silent: true })
+    const rerun = repairLinks(graph, { fix: false, silent: true })
     hasBadLinks = rerun.hasBadLinks
   }
 
diff --git a/packages/workflow-validation/src/linkTopology.test.ts b/packages/workflow-validation/src/linkTopology.test.ts
new file mode 100644
index 00000000000..d13b443c4c0
--- /dev/null
+++ b/packages/workflow-validation/src/linkTopology.test.ts
@@ -0,0 +1,164 @@
+import { describe, expect, it } from 'vitest'
+
+import { describeTopologyError, validateLinkTopology } from './linkTopology'
+import type { SerialisedGraph } from './serialised'
+
+function makeGraph(partial: Partial<SerialisedGraph>): SerialisedGraph {
+  return { nodes: [], links: [], ...partial }
+}
+
+describe('validateLinkTopology', () => {
+  it('returns no errors for a valid graph', () => {
+    const graph = makeGraph({
+      nodes: [
+        { id: 1, outputs: [{ name: 'o', type: '*', links: [10] }] },
+        { id: 2, inputs: [{ name: 'i', type: '*', link: 10 }] }
+      ],
+      links: [[10, 1, 0, 2, 0, '*']]
+    })
+    expect(validateLinkTopology(graph)).toEqual([])
+  })
+
+  it('reports target slot out of bounds (seedance regression)', () => {
+    const graph = makeGraph({
+      nodes: [
+        { id: 9, outputs: [{ name: 'o', type: 'STRING', links: [29] }] },
+        {
+          id: 14,
+          inputs: [
+            { name: 'a', type: 'STRING', link: null },
+            { name: 'b', type: 'STRING', link: null },
+            { name: 'c', type: 'STRING', link: null },
+            { name: 'd', type: 'STRING', link: 55 },
+            { name: 'e', type: 'STRING', link: null }
+          ]
+        }
+      ],
+      links: [[29, 9, 0, 14, 9, 'STRING']]
+    })
+    const errors = validateLinkTopology(graph)
+    expect(errors).toHaveLength(1)
+    expect(errors[0]).toMatchObject({
+      kind: 'target-slot-out-of-bounds',
+      link: { linkId: 29, targetId: 14, targetSlot: 9 },
+      targetSlotCount: 5
+    })
+    expect(describeTopologyError(errors[0]!)).toContain(
+      '[link=29 src=9:0 tgt=14:9]'
+    )
+  })
+
+  it('reports a missing origin node', () => {
+    const graph = makeGraph({
+      nodes: [{ id: 2, inputs: [{ name: 'i', type: '*', link: 10 }] }],
+      links: [[10, 999, 0, 2, 0, '*']]
+    })
+    const errors = validateLinkTopology(graph)
+    expect(errors[0]?.kind).toBe('missing-origin-node')
+  })
+
+  it('reports a target-link mismatch', () => {
+    const graph = makeGraph({
+      nodes: [
+        { id: 1, outputs: [{ name: 'o', type: '*', links: [10] }] },
+        { id: 2, inputs: [{ name: 'i', type: '*', link: 999 }] }
+      ],
+      links: [[10, 1, 0, 2, 0, '*']]
+    })
+    const errors = validateLinkTopology(graph)
+    expect(errors[0]).toMatchObject({
+      kind: 'target-link-mismatch',
+      actualLink: 999
+    })
+  })
+
+  it('accepts object-form links for valid graphs', () => {
+    const graph = makeGraph({
+      nodes: [
+        { id: 1, outputs: [{ name: 'o', type: '*', links: [10] }] },
+        { id: 2, inputs: [{ name: 'i', type: '*', link: 10 }] }
+      ],
+      links: [
+        {
+          id: 10,
+          origin_id: 1,
+          origin_slot: 0,
+          target_id: 2,
+          target_slot: 0,
+          type: '*'
+        }
+      ]
+    })
+    expect(validateLinkTopology(graph)).toEqual([])
+  })
+
+  it('reports object-form links with out-of-bounds slots', () => {
+    const graph = makeGraph({
+      nodes: [
+        { id: 1, outputs: [{ name: 'o', type: '*', links: [10] }] },
+        {
+          id: 2,
+          inputs: [{ name: 'a', type: '*', link: null }]
+        }
+      ],
+      links: [
+        {
+          id: 10,
+          origin_id: 1,
+          origin_slot: 0,
+          target_id: 2,
+          target_slot: 5,
+          type: '*'
+        }
+      ]
+    })
+    const errors = validateLinkTopology(graph)
+    expect(errors[0]).toMatchObject({
+      kind: 'target-slot-out-of-bounds',
+      link: { linkId: 10, targetId: 2, targetSlot: 5 }
+    })
+  })
+})
+
+describe('describeTopologyError', () => {
+  it('formats every error kind with the [linkId, src, srcSlot, tgt, tgtSlot] tuple', () => {
+    const link = {
+      linkId: 7,
+      originId: 3,
+      originSlot: 1,
+      targetId: 4,
+      targetSlot: 2
+    }
+    const tuple = '[link=7 src=3:1 tgt=4:2]'
+    expect(
+      describeTopologyError({ kind: 'missing-origin-node', link })
+    ).toContain(tuple)
+    expect(
+      describeTopologyError({ kind: 'missing-target-node', link })
+    ).toContain(tuple)
+    expect(
+      describeTopologyError({
+        kind: 'origin-slot-out-of-bounds',
+        link,
+        originSlotCount: 0
+      })
+    ).toContain(tuple)
+    expect(
+      describeTopologyError({
+        kind: 'target-slot-out-of-bounds',
+        link,
+        targetSlotCount: 5
+      })
+    ).toContain(tuple)
+    expect(
+      describeTopologyError({ kind: 'origin-link-not-listed', link })
+    ).toContain(tuple)
+    expect(
+      describeTopologyError({
+        kind: 'target-link-mismatch',
+        link,
+        actualLink: null
+      })
+    ).toContain(tuple)
+  })
+})
diff --git a/packages/workflow-validation/src/linkTopology.ts b/packages/workflow-validation/src/linkTopology.ts
new file mode 100644
index 00000000000..0086c7c3dbf
--- /dev/null
+++ b/packages/workflow-validation/src/linkTopology.ts
@@ -0,0 +1,158 @@
+import type {
+  SerialisedGraph,
+  SerialisedLinkArray,
+  SerialisedLinkObject,
+  SerialisedNode
+} from './serialised'
+
+export interface LinkContext {
+  linkId: number
+  originId: string | number
+  originSlot: number
+  targetId: string | number
+  targetSlot: number
+}
+
+export type TopologyError =
+  | { kind: 'missing-origin-node'; link: LinkContext }
+  | { kind: 'missing-target-node'; link: LinkContext }
+  | {
+      kind: 'origin-slot-out-of-bounds'
+      link: LinkContext
+      originSlotCount: number
+    }
+  | {
+      kind: 'target-slot-out-of-bounds'
+      link: LinkContext
+      targetSlotCount: number
+    }
+  | { kind: 'origin-link-not-listed'; link: LinkContext }
+  | {
+      kind: 'target-link-mismatch'
+      link: LinkContext
+      actualLink: number | null
+    }
+
+export function describeTopologyError(error: TopologyError): string {
+  const { linkId, originId, originSlot, targetId, targetSlot } = error.link
+  const tuple = `[link=${linkId} src=${originId}:${originSlot} tgt=${targetId}:${targetSlot}]`
+  switch (error.kind) {
+    case 'missing-origin-node':
+      return `${tuple} origin node ${originId} does not exist in graph`
+    case 'missing-target-node':
+      return `${tuple} target node ${targetId} does not exist in graph`
+    case 'origin-slot-out-of-bounds':
+      return `${tuple} origin slot ${originSlot} is out of bounds; node ${originId} has ${error.originSlotCount} output slot(s)`
+    case 'target-slot-out-of-bounds':
+      return `${tuple} target slot ${targetSlot} is out of bounds; node ${targetId} has ${error.targetSlotCount} input slot(s)`
+    case 'origin-link-not-listed':
+      return `${tuple} link is not listed in node ${originId}.outputs[${originSlot}].links`
+    case 'target-link-mismatch':
+      return `${tuple} node ${targetId}.inputs[${targetSlot}].link is ${error.actualLink}, expected ${linkId}`
+  }
+}
+
+function isLinkObject(
+  l: SerialisedLinkArray | SerialisedLinkObject
+): l is SerialisedLinkObject {
+  return !Array.isArray(l) && typeof l === 'object'
+}
+
+export function toLinkContext(
+  l: SerialisedLinkArray | SerialisedLinkObject
+): LinkContext {
+  if (isLinkObject(l)) {
+    return {
+      linkId: l.id,
+      originId: l.origin_id,
+      originSlot: l.origin_slot,
+      targetId: l.target_id,
+      targetSlot: l.target_slot
+    }
+  }
+  return {
+    linkId: l[0],
+    originId: l[1],
+    originSlot: l[2],
+    targetId: l[3],
+    targetSlot: l[4]
+  }
+}
+
+function getNodeById(
+  graph: SerialisedGraph,
+  id: string | number
+): SerialisedNode | undefined {
+  return graph.nodes.find((n) => n.id == id)
+}
+
+function iterateLinks(
+  graph: SerialisedGraph
+): Array<SerialisedLinkArray | SerialisedLinkObject> {
+  if (Array.isArray(graph.links)) {
+    return graph.links.filter(
+      (l): l is SerialisedLinkArray | SerialisedLinkObject => l != null
+    )
+  }
+  const result: Array<SerialisedLinkArray | SerialisedLinkObject> = []
+  for (const l of Object.values(graph.links)) {
+    if (l) result.push(l as SerialisedLinkObject)
+  }
+  return result
+}
+
+/**
+ * Pure topology check: every link must reference real nodes, in-bounds
+ * slots, and consistent input/output endpoints. Does not mutate the
+ * graph. Use `repairLinks` (separate module) to attempt auto-fix.
+ */
+export function validateLinkTopology(graph: SerialisedGraph): TopologyError[] {
+  const errors: TopologyError[] = []
+  for (const l of iterateLinks(graph)) {
+    const link = toLinkContext(l)
+    const origin = getNodeById(graph, link.originId)
+    const target = getNodeById(graph, link.targetId)
+
+    if (!origin) errors.push({ kind: 'missing-origin-node', link })
+    if (!target) errors.push({ kind: 'missing-target-node', link })
+    if (!origin || !target) continue
+
+    const outputs = origin.outputs ?? []
+    const originSlotOutOfBounds =
+      link.originSlot < 0 || link.originSlot >= outputs.length
+    if (originSlotOutOfBounds) {
+      errors.push({
+        kind: 'origin-slot-out-of-bounds',
+        link,
+        originSlotCount: outputs.length
+      })
+    }
+    const inputs = target.inputs ?? []
+    const targetSlotOutOfBounds =
+      link.targetSlot < 0 || link.targetSlot >= inputs.length
+    if (targetSlotOutOfBounds) {
+      errors.push({
+        kind: 'target-slot-out-of-bounds',
+        link,
+        targetSlotCount: inputs.length
+      })
+    }
+    if (originSlotOutOfBounds || targetSlotOutOfBounds) {
+      continue
+    }
+
+    const originLinks = outputs[link.originSlot]?.links ?? []
+    if (!originLinks.includes(link.linkId)) {
+      errors.push({ kind: 'origin-link-not-listed', link })
+    }
+    const targetLink = inputs[link.targetSlot]?.link ?? null
+    if (targetLink !== link.linkId) {
+      errors.push({
+        kind: 'target-link-mismatch',
+        link,
+        actualLink: targetLink
+      })
+    }
+  }
+  return errors
+}
diff --git a/packages/workflow-validation/src/serialised.ts b/packages/workflow-validation/src/serialised.ts
new file mode 100644
index 00000000000..c35ae4288e5
--- /dev/null
+++ b/packages/workflow-validation/src/serialised.ts
@@ -0,0 +1,60 @@
+/**
+ * Minimal structural types for serialised workflow JSON.
+ *
+ * The validation/repair code in this package operates on plain JSON
+ * (parsed `.json` workflow files) — it does NOT need the runtime
+ * `LGraph`/`LGraphNode` classes from litegraph. Defining the shapes
+ * locally keeps this package free of frontend/litegraph coupling so
+ * it can be consumed by Node.js CI scripts and a future backend
+ * validator.
+ *
+ * These types intentionally mirror the relevant fields used by
+ * `validateLinkTopology` and `repairLinks`. They are a subset of the
+ * `ISerialisedGraph` / `ISerialisedNode` shapes from
+ * `@/lib/litegraph/src/types/serialisation` and stay structurally
+ * compatible with them.
+ */
+
+/** Schema version 0.4 link tuple: `[id, originId, originSlot, targetId, targetSlot, type]`. */
+export type SerialisedLinkArray = [
+  number,
+  string | number,
+  number,
+  string | number,
+  number,
+  string | string[] | number
+]
+
+/** Object form of a link (schema version 1, or after live-graph hydration). */
+export interface SerialisedLinkObject {
+  id: number
+  origin_id: string | number
+  origin_slot: number
+  target_id: string | number
+  target_slot: number
+  type?: string | string[] | number
+}
+
+export interface SerialisedNodeInput {
+  name?: string
+  type?: string | string[] | number
+  link?: number | null
+}
+
+export interface SerialisedNodeOutput {
+  name?: string
+  type?: string | string[] | number
+  links?: number[] | null
+}
+
+export interface SerialisedNode {
+  id: string | number
+  type?: string
+  inputs?: SerialisedNodeInput[]
+  outputs?: SerialisedNodeOutput[]
+}
+
+export interface SerialisedGraph {
+  nodes: SerialisedNode[]
+  links: Array<SerialisedLinkArray | SerialisedLinkObject | null>
+}
diff --git a/src/platform/workflow/validation/schemas/workflowSchema.ts b/packages/workflow-validation/src/workflowSchema.ts
similarity index 98%
rename from src/platform/workflow/validation/schemas/workflowSchema.ts
rename to packages/workflow-validation/src/workflowSchema.ts
index 1f1dc3fefc5..2dc018399b6 100644
--- a/src/platform/workflow/validation/schemas/workflowSchema.ts
+++ b/packages/workflow-validation/src/workflowSchema.ts
@@ -1,7 +1,8 @@
 import { z } from 'zod'
 import type { SafeParseReturnType } from 'zod'
 import { fromZodError } from 'zod-validation-error'
-import type { RendererType } from '@/lib/litegraph/src/LGraph'
+
+type RendererType = 'LG' | 'Vue' | 'Vue-corrected'
 
 const zRendererType = z.enum([
   'LG',
@@ -313,7 +314,16 @@ const zExtra = z
   .passthrough()
 
 const zGraphDefinitions = z.object({
-  subgraphs: z.lazy(() => z.array(zSubgraphDefinition))
+  subgraphs: z.lazy(
+    (): z.ZodArray<
+      z.ZodType<
+        SubgraphDefinitionBase<ComfyWorkflow1BaseOutput>,
+        z.ZodTypeDef,
+        SubgraphDefinitionBase<ComfyWorkflow1BaseInput>
+      >,
+      'many'
+    > => z.array(zSubgraphDefinition)
+  )
 })
 
 const zBaseExportableGraph = z.object({
diff --git a/packages/workflow-validation/tsconfig.json b/packages/workflow-validation/tsconfig.json
new file mode 100644
index 00000000000..5665cf5d7ea
--- /dev/null
+++ b/packages/workflow-validation/tsconfig.json
@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist"
+  },
+  "include": ["src/**/*"],
+  "references": [{ "path": "./tsconfig.node.json" }]
+}
diff --git a/packages/workflow-validation/tsconfig.node.json b/packages/workflow-validation/tsconfig.node.json
new file mode 100644
index 00000000000..70984c3e8a5
--- /dev/null
+++ b/packages/workflow-validation/tsconfig.node.json
@@ -0,0 +1,10 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "composite": true,
+    "outDir": "dist/.tsnode",
+    "module": "ESNext",
+    "moduleResolution": "bundler"
+  },
+  "include": ["vite.config.mts"]
+}
diff --git a/packages/workflow-validation/vite.config.mts b/packages/workflow-validation/vite.config.mts
new file mode 100644
index 00000000000..c3a453d9665
--- /dev/null
+++ b/packages/workflow-validation/vite.config.mts
@@ -0,0 +1,26 @@
+import { resolve } from 'path'
+import { defineConfig } from 'vite'
+import dts from 'vite-plugin-dts'
+
+export default defineConfig({
+  build: {
+    lib: {
+      entry: resolve(__dirname, 'src/index.ts'),
+      name: 'workflow-validation',
+      formats: ['es'],
+      fileName: 'index'
+    },
+    copyPublicDir: false,
+    minify: false,
+    rollupOptions: {
+      external: ['zod', 'zod-validation-error']
+    }
+  },
+  plugins: [
+    dts({
+      tsconfigPath: 'tsconfig.json',
+      include: ['src/**/*'],
+      exclude: ['src/**/*.test.ts']
+    })
+  ]
+})
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3bf369cc142..8c4cf1c2bc1 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -443,6 +443,9 @@ importers:
       '@comfyorg/tailwind-utils':
         specifier: workspace:*
         version: link:packages/tailwind-utils
+      '@comfyorg/workflow-validation':
+        specifier: workspace:*
+        version: link:packages/workflow-validation
       '@formkit/auto-animate':
         specifier: 'catalog:'
         version: 0.9.0
@@ -1062,6 +1065,25 @@ importers:
         specifier: 'catalog:'
         version: 5.9.3
 
+  packages/workflow-validation:
+    dependencies:
+      zod:
+        specifier: 'catalog:'
+        version: 3.25.76
+      zod-validation-error:
+        specifier: 'catalog:'
+        version: 3.3.0(zod@3.25.76)
+    devDependencies:
+      typescript:
+        specifier: 'catalog:'
+        version: 5.9.3
+      vite:
+        specifier: ^8.0.0
+        version: 8.0.0(@types/node@25.0.3)(esbuild@0.27.3)(jiti@2.6.1)(terser@5.39.2)(tsx@4.19.4)(yaml@2.8.2)
+      vite-plugin-dts:
+        specifier: 'catalog:'
+        version: 4.5.4(@types/node@25.0.3)(rollup@4.53.5)(typescript@5.9.3)(vite@8.0.0(@types/node@25.0.3)(esbuild@0.27.3)(jiti@2.6.1)(terser@5.39.2)(tsx@4.19.4)(yaml@2.8.2))
+
 packages:
 
   '@acemir/cssom@0.9.30':
@@ -12245,6 +12267,14 @@ snapshots:
     transitivePeerDependencies:
       - '@types/node'
 
+  '@microsoft/api-extractor-model@7.33.1(@types/node@25.0.3)':
+    dependencies:
+      '@microsoft/tsdoc': 0.16.0
+      '@microsoft/tsdoc-config': 0.18.0
+      '@rushstack/node-core-library': 5.20.1(@types/node@25.0.3)
+    transitivePeerDependencies:
+      - '@types/node'
+
   '@microsoft/api-extractor@7.57.2(@types/node@24.10.4)':
     dependencies:
       '@microsoft/api-extractor-model': 7.33.1(@types/node@24.10.4)
@@ -12264,6 +12294,25 @@ snapshots:
     transitivePeerDependencies:
       - '@types/node'
 
+  '@microsoft/api-extractor@7.57.2(@types/node@25.0.3)':
+    dependencies:
+      '@microsoft/api-extractor-model': 7.33.1(@types/node@25.0.3)
+      '@microsoft/tsdoc': 0.16.0
+      '@microsoft/tsdoc-config': 0.18.0
+      '@rushstack/node-core-library': 5.20.1(@types/node@25.0.3)
+      '@rushstack/rig-package': 0.7.1
+      '@rushstack/terminal': 0.22.1(@types/node@25.0.3)
+      '@rushstack/ts-command-line': 5.3.1(@types/node@25.0.3)
+      diff: 8.0.3
+      lodash: 4.17.23
+      minimatch: 10.2.1
+      resolve: 1.22.11
+      semver: 7.5.4
+      source-map: 0.6.1
+      typescript: 5.8.2
+    transitivePeerDependencies:
+      - '@types/node'
+
   '@microsoft/tsdoc-config@0.18.0':
     dependencies:
       '@microsoft/tsdoc': 0.16.0
@@ -13136,10 +13185,27 @@ snapshots:
     optionalDependencies:
       '@types/node': 24.10.4
 
+  '@rushstack/node-core-library@5.20.1(@types/node@25.0.3)':
+    dependencies:
+      ajv: 8.13.0
+      ajv-draft-04: 1.0.0(ajv@8.13.0)
+      ajv-formats: 3.0.1(ajv@8.13.0)
+      fs-extra: 11.3.2
+      import-lazy: 4.0.0
+      jju: 1.4.0
+      resolve: 1.22.11
+      semver: 7.5.4
+    optionalDependencies:
+      '@types/node': 25.0.3
+
   '@rushstack/problem-matcher@0.2.1(@types/node@24.10.4)':
     optionalDependencies:
       '@types/node': 24.10.4
 
+  '@rushstack/problem-matcher@0.2.1(@types/node@25.0.3)':
+    optionalDependencies:
+      '@types/node': 25.0.3
+
   '@rushstack/rig-package@0.7.1':
     dependencies:
       resolve: 1.22.11
@@ -13153,6 +13219,14 @@ snapshots:
     optionalDependencies:
       '@types/node': 24.10.4
 
+  '@rushstack/terminal@0.22.1(@types/node@25.0.3)':
+    dependencies:
+      '@rushstack/node-core-library': 5.20.1(@types/node@25.0.3)
+      '@rushstack/problem-matcher': 0.2.1(@types/node@25.0.3)
+      supports-color: 8.1.1
+    optionalDependencies:
+      '@types/node': 25.0.3
+
   '@rushstack/ts-command-line@5.3.1(@types/node@24.10.4)':
     dependencies:
       '@rushstack/terminal': 0.22.1(@types/node@24.10.4)
@@ -13162,6 +13236,15 @@ snapshots:
     transitivePeerDependencies:
       - '@types/node'
 
+  '@rushstack/ts-command-line@5.3.1(@types/node@25.0.3)':
+    dependencies:
+      '@rushstack/terminal': 0.22.1(@types/node@25.0.3)
+      '@types/argparse': 1.0.38
+      argparse: 1.0.10
+      string-argv: 0.3.2
+    transitivePeerDependencies:
+      - '@types/node'
+
   '@sec-ant/readable-stream@0.4.1': {}
 
   '@sentry-internal/browser-utils@10.32.1':
@@ -14189,7 +14272,7 @@ snapshots:
       sirv: 3.0.2
       tinyglobby: 0.2.15
       tinyrainbow: 3.0.3
-      vitest: 4.0.16(@opentelemetry/api@1.9.0)(@types/node@24.10.4)(@vitest/ui@4.0.16)(esbuild@0.27.3)(happy-dom@20.0.11)(jiti@2.6.1)(jsdom@27.4.0)(terser@5.39.2)(tsx@4.19.4)(yaml@2.8.2)
+      vitest: 4.0.16(@opentelemetry/api@1.9.0)(@types/node@25.0.3)(@vitest/ui@4.0.16)(esbuild@0.27.3)(happy-dom@20.0.11)(jiti@2.6.1)(jsdom@27.4.0)(terser@5.39.2)(tsx@4.19.4)(yaml@2.8.2)
 
   '@vitest/utils@3.2.4':
     dependencies:
@@ -20144,6 +20227,25 @@ snapshots:
       - rollup
       - supports-color
 
+  vite-plugin-dts@4.5.4(@types/node@25.0.3)(rollup@4.53.5)(typescript@5.9.3)(vite@8.0.0(@types/node@25.0.3)(esbuild@0.27.3)(jiti@2.6.1)(terser@5.39.2)(tsx@4.19.4)(yaml@2.8.2)):
+    dependencies:
+      '@microsoft/api-extractor': 7.57.2(@types/node@25.0.3)
+      '@rollup/pluginutils': 5.3.0(rollup@4.53.5)
+      '@volar/typescript': 2.4.28
+      '@vue/language-core': 2.2.0(typescript@5.9.3)
+      compare-versions: 6.1.1
+      debug: 4.4.3
+      kolorist: 1.8.0
+      local-pkg: 1.1.2
+      magic-string: 0.30.21
+      typescript: 5.9.3
+    optionalDependencies:
+      vite: 8.0.0(@types/node@25.0.3)(esbuild@0.27.3)(jiti@2.6.1)(terser@5.39.2)(tsx@4.19.4)(yaml@2.8.2)
+    transitivePeerDependencies:
+      - '@types/node'
+      - rollup
+      - supports-color
+
   vite-plugin-html@3.2.2(vite@8.0.0(@types/node@24.10.4)(esbuild@0.27.3)(jiti@2.6.1)(terser@5.39.2)(tsx@4.19.4)(yaml@2.8.2)):
     dependencies:
       '@rollup/pluginutils': 4.2.1
diff --git a/scripts/generate-json-schema.ts b/scripts/generate-json-schema.ts
index 1a205662645..8247d74fc96 100644
--- a/scripts/generate-json-schema.ts
+++ b/scripts/generate-json-schema.ts
@@ -2,10 +2,7 @@ import fs from 'fs'
 import path from 'path'
 import { zodToJsonSchema } from 'zod-to-json-schema'
 
-import {
-  zComfyWorkflow,
-  zComfyWorkflow1
-} from '../src/platform/workflow/validation/schemas/workflowSchema'
+import { zComfyWorkflow, zComfyWorkflow1 } from '@comfyorg/workflow-validation'
 import { zComfyNodeDef as zComfyNodeDefV2 } from '../src/schemas/nodeDef/nodeDefSchemaV2'
 import { zComfyNodeDef as zComfyNodeDefV1 } from '../src/schemas/nodeDefSchema'
 
@@ -57,4 +54,4 @@ fs.writeFileSync(
   JSON.stringify(nodeDefV2Schema, null, 2)
 )
 
-console.log('JSON Schemas generated successfully!')
+console.warn('JSON Schemas generated successfully!')
diff --git a/scripts/prepare-workflow-validation.ts b/scripts/prepare-workflow-validation.ts
new file mode 100644
index 00000000000..cd2fabc2611
--- /dev/null
+++ b/scripts/prepare-workflow-validation.ts
@@ -0,0 +1,96 @@
+import fs from 'fs'
+import path from 'path'
+import { fileURLToPath } from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+const repoRoot = path.resolve(__dirname, '..')
+const packageDir = path.join(repoRoot, 'packages', 'workflow-validation')
+const distDir = path.join(packageDir, 'dist')
+
+interface SourcePackage {
+  name: string
+  version: string
+  description?: string
+  license?: string
+  repository?: string
+  homepage?: string
+  dependencies?: Record<string, string>
+  publishConfig?: Record<string, unknown>
+}
+
+const sourcePackage = JSON.parse(
+  fs.readFileSync(path.join(packageDir, 'package.json'), 'utf8')
+) as SourcePackage
+
+const workspaceYaml =
+  fs
+    .readFileSync(path.join(repoRoot, 'pnpm-workspace.yaml'), 'utf8')
+    .replace(/\r\n/g, '\n') + '\n___end:'
+
+const workspaceCatalog =
+  workspaceYaml.match(/^catalog:\n([\s\S]*?)\n\S/m)?.[1] ?? ''
+
+function resolveCatalog(name: string): string {
+  const sourceVersion = sourcePackage.dependencies?.[name]
+  if (sourceVersion && sourceVersion !== 'catalog:') return sourceVersion
+  const re = new RegExp(`^\\s+'?${name}'?:\\s*([^\\n]+)$`, 'm')
+  const match = workspaceCatalog.match(re)
+  if (!match) {
+    throw new Error(
+      `Could not resolve catalog version for ${name}. ` +
+        `Expected entry under \`catalog:\` in pnpm-workspace.yaml.`
+    )
+  }
+  return match[1]!.trim()
+}
+
+const distPackage = {
+  name: sourcePackage.name,
+  version: sourcePackage.version,
+  description: sourcePackage.description,
+  license: sourcePackage.license,
+  repository: sourcePackage.repository,
+  homepage: sourcePackage.homepage,
+  type: 'module',
+  main: './index.js',
+  module: './index.js',
+  types: './index.d.ts',
+  exports: {
+    '.': {
+      types: './index.d.ts',
+      import: './index.js'
+    },
+    './linkRepair': {
+      types: './linkRepair.d.ts',
+      import: './index.js'
+    },
+    './linkTopology': {
+      types: './linkTopology.d.ts',
+      import: './index.js'
+    },
+    './workflowSchema': {
+      types: './workflowSchema.d.ts',
+      import: './index.js'
+    },
+    './serialised': {
+      types: './serialised.d.ts',
+      import: './index.js'
+    }
+  },
+  files: ['*.js', '*.d.ts'],
+  publishConfig: sourcePackage.publishConfig ?? { access: 'public' },
+  dependencies: {
+    zod: resolveCatalog('zod'),
+    'zod-validation-error': resolveCatalog('zod-validation-error')
+  }
+}
+
+if (!fs.existsSync(distDir)) {
+  fs.mkdirSync(distDir, { recursive: true })
+}
+
+fs.writeFileSync(
+  path.join(distDir, 'package.json'),
+  JSON.stringify(distPackage, null, 2) + '\n'
+)
+console.warn(`Prepared ${distPackage.name}@${distPackage.version} in dist/`)
diff --git a/src/locales/en/main.json b/src/locales/en/main.json
index 882b61245c1..c4b7b54c6d4 100644
--- a/src/locales/en/main.json
+++ b/src/locales/en/main.json
@@ -2261,7 +2261,22 @@
       "special": "Must contain at least one special character",
       "match": "Passwords must match"
     },
-    "personalDataConsentRequired": "You must agree to the processing of your personal data."
+    "personalDataConsentRequired": "You must agree to the processing of your personal data.",
+    "topology": {
+      "invalidLinks": "Workflow has {count} invalid link | Workflow has {count} invalid links",
+      "overflow": "…and {count} more (see console for full list)",
+      "abortedSummary": "Workflow has unrepairable invalid links",
+      "validationSummary": "Workflow Validation",
+      "linksFixedSummary": "Workflow Links Fixed",
+      "linksFixedDetail": "Fixed {patched} node connections and removed {deleted} invalid links.",
+      "tuple": "[link={linkId} src={originId}:{originSlot} tgt={targetId}:{targetSlot}]",
+      "missingOriginNode": "{tuple} origin node {originId} does not exist in graph",
+      "missingTargetNode": "{tuple} target node {targetId} does not exist in graph",
+      "originSlotOutOfBounds": "{tuple} origin slot {originSlot} is out of bounds; node {originId} has {count} output slot | {tuple} origin slot {originSlot} is out of bounds; node {originId} has {count} output slots",
+      "targetSlotOutOfBounds": "{tuple} target slot {targetSlot} is out of bounds; node {targetId} has {count} input slot | {tuple} target slot {targetSlot} is out of bounds; node {targetId} has {count} input slots",
+      "originLinkNotListed": "{tuple} link is not listed in node {originId}.outputs[{originSlot}].links",
+      "targetLinkMismatch": "{tuple} node {targetId}.inputs[{targetSlot}].link is {actualLink}, expected {linkId}"
+    }
   },
   "credits": {
     "activity": "Activity",
diff --git a/src/platform/workflow/validation/composables/useWorkflowValidation.test.ts b/src/platform/workflow/validation/composables/useWorkflowValidation.test.ts
new file mode 100644
index 00000000000..ae0a7ca3be0
--- /dev/null
+++ b/src/platform/workflow/validation/composables/useWorkflowValidation.test.ts
@@ -0,0 +1,257 @@
+import { LinkRepairAbortedError } from '@comfyorg/workflow-validation'
+import type {
+  ComfyWorkflowJSON,
+  RepairResult,
+  TopologyError
+} from '@comfyorg/workflow-validation'
+import type * as WorkflowValidationModule from '@comfyorg/workflow-validation'
+import { createPinia, setActivePinia } from 'pinia'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { useWorkflowValidation } from './useWorkflowValidation'
+
+const toastAddMock = vi.hoisted(() => vi.fn())
+const toastAddAlertMock = vi.hoisted(() => vi.fn())
+
+vi.mock('@/platform/updates/common/toastStore', () => ({
+  useToastStore: () => ({
+    add: toastAddMock,
+    addAlert: toastAddAlertMock
+  })
+}))
+
+vi.mock('vue-i18n', () => ({
+  useI18n: () => ({
+    t: (key: string, ...rest: unknown[]) => {
+      const last = rest[rest.length - 1]
+      const params =
+        last && typeof last === 'object' && 'named' in (last as object)
+          ? (last as { named: Record<string, unknown> }).named
+          : (last as Record<string, unknown> | undefined)
+      if (!params) return key
+      return `${key}|${JSON.stringify(params)}`
+    }
+  })
+}))
+
+const validateLinkTopologyMock = vi.hoisted(() => vi.fn())
+const repairLinksMock = vi.hoisted(() => vi.fn())
+const describeTopologyErrorMock = vi.hoisted(() =>
+  vi.fn((e: TopologyError) => `desc:${e.kind}:${e.link.linkId}`)
+)
+
+vi.mock('@comfyorg/workflow-validation', async () => {
+  const actual = await vi.importActual<typeof WorkflowValidationModule>(
+    '@comfyorg/workflow-validation'
+  )
+  return {
+    ...actual,
+    validateLinkTopology: validateLinkTopologyMock,
+    repairLinks: repairLinksMock,
+    describeTopologyError: describeTopologyErrorMock
+  }
+})
+
+const validateComfyWorkflowMock = vi.hoisted(() => vi.fn())
+vi.mock('@/platform/workflow/validation/schemas/workflowSchema', () => ({
+  validateComfyWorkflow: validateComfyWorkflowMock
+}))
+
+vi.mock('@/scripts/utils', () => ({
+  clone: <T>(v: T): T => structuredClone(v)
+}))
+
+function makeLink(linkId: number) {
+  return {
+    linkId,
+    originId: 1,
+    originSlot: 0,
+    targetId: 2,
+    targetSlot: 0
+  }
+}
+
+function makeWorkflow(): ComfyWorkflowJSON {
+  return {
+    version: 0.4,
+    last_node_id: 2,
+    last_link_id: 1,
+    nodes: [
+      { id: 1, outputs: [{ name: 'o', type: '*', links: [1] }] },
+      { id: 2, inputs: [{ name: 'i', type: '*', link: 1 }] }
+    ] as unknown as ComfyWorkflowJSON['nodes'],
+    links: [[1, 1, 0, 2, 0, '*']] as unknown as ComfyWorkflowJSON['links']
+  } as ComfyWorkflowJSON
+}
+
+function repairResult(
+  graph: ComfyWorkflowJSON,
+  overrides: Partial<RepairResult> = {}
+): RepairResult {
+  return {
+    graph: graph as unknown as RepairResult['graph'],
+    hasBadLinks: false,
+    fixed: false,
+    patched: 0,
+    deleted: 0,
+    ...overrides
+  }
+}
+
+describe('useWorkflowValidation', () => {
+  beforeEach(() => {
+    setActivePinia(createPinia())
+    toastAddMock.mockClear()
+    toastAddAlertMock.mockClear()
+    validateLinkTopologyMock.mockReset()
+    repairLinksMock.mockReset()
+    describeTopologyErrorMock.mockClear()
+    validateComfyWorkflowMock.mockReset()
+  })
+
+  afterEach(() => vi.restoreAllMocks())
+
+  it('returns null when schema validation fails', async () => {
+    validateComfyWorkflowMock.mockImplementation(async (_d, onError) => {
+      onError('bad schema')
+      return null
+    })
+
+    const { validateWorkflow } = useWorkflowValidation()
+    const out = await validateWorkflow(makeWorkflow())
+
+    expect(out.graphData).toBeNull()
+    expect(toastAddAlertMock).toHaveBeenCalledWith('bad schema')
+    expect(repairLinksMock).not.toHaveBeenCalled()
+  })
+
+  it('passes through when schema validation succeeds and no topology errors exist', async () => {
+    const wf = makeWorkflow()
+    validateComfyWorkflowMock.mockResolvedValue(wf)
+    validateLinkTopologyMock.mockReturnValue([])
+    repairLinksMock.mockImplementation((g) => repairResult(g))
+
+    const { validateWorkflow } = useWorkflowValidation()
+    const out = await validateWorkflow(wf)
+
+    expect(out.graphData).not.toBeNull()
+    expect(toastAddMock).not.toHaveBeenCalled()
+  })
+
+  it('emits a single warn toast summarising up to TOPOLOGY_TOAST_LIMIT errors', async () => {
+    const wf = makeWorkflow()
+    const errors: TopologyError[] = Array.from({ length: 7 }, (_v, i) => ({
+      kind: 'missing-origin-node',
+      link: makeLink(i + 1)
+    }))
+    validateComfyWorkflowMock.mockResolvedValue(wf)
+    validateLinkTopologyMock.mockReturnValue(errors)
+    repairLinksMock.mockImplementation((g) => repairResult(g))
+
+    const { validateWorkflow } = useWorkflowValidation()
+    await validateWorkflow(wf)
+
+    const warns = toastAddMock.mock.calls.filter(([arg]) =>
+      (arg as { summary: string }).summary.startsWith(
+        'validation.topology.invalidLinks'
+      )
+    )
+    expect(warns).toHaveLength(1)
+    const detail = (warns[0]![0] as { detail: string }).detail
+    expect(detail).toContain('validation.topology.overflow')
+    expect(detail.split('\n')).toHaveLength(6)
+  })
+
+  it('shows the success toast when repair fixes links', async () => {
+    const wf = makeWorkflow()
+    validateComfyWorkflowMock.mockResolvedValue(wf)
+    validateLinkTopologyMock.mockReturnValue([])
+    repairLinksMock.mockImplementation((g) =>
+      repairResult(g, { fixed: true, patched: 2, deleted: 1 })
+    )
+
+    const { validateWorkflow } = useWorkflowValidation()
+    await validateWorkflow(wf)
+
+    expect(toastAddMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        severity: 'success',
+        summary: expect.stringContaining(
+          'validation.topology.linksFixedSummary'
+        )
+      })
+    )
+  })
+
+  it('returns null and emits an error toast on LinkRepairAbortedError', async () => {
+    const wf = makeWorkflow()
+    const topologyError: TopologyError = {
+      kind: 'target-slot-out-of-bounds',
+      link: makeLink(7),
+      targetSlotCount: 5
+    }
+    validateComfyWorkflowMock.mockResolvedValue(wf)
+    validateLinkTopologyMock.mockReturnValue([topologyError])
+    repairLinksMock.mockImplementation(() => {
+      throw new LinkRepairAbortedError(topologyError)
+    })
+
+    const { validateWorkflow } = useWorkflowValidation()
+    const out = await validateWorkflow(wf)
+
+    expect(out.graphData).toBeNull()
+    const errorToast = toastAddMock.mock.calls.find(
+      ([arg]) => (arg as { severity: string }).severity === 'error'
+    )
+    expect(errorToast).toBeDefined()
+    expect((errorToast![0] as { summary: string }).summary).toContain(
+      'validation.topology.abortedSummary'
+    )
+  })
+
+  it('re-throws unexpected errors from repairLinks', async () => {
+    const wf = makeWorkflow()
+    validateComfyWorkflowMock.mockResolvedValue(wf)
+    validateLinkTopologyMock.mockReturnValue([])
+    repairLinksMock.mockImplementation(() => {
+      throw new TypeError('boom')
+    })
+
+    const { validateWorkflow } = useWorkflowValidation()
+    await expect(validateWorkflow(wf)).rejects.toThrow(TypeError)
+  })
+
+  it('clones graphData before passing to repairLinks so the abort fallback is untouched', async () => {
+    const wf = makeWorkflow()
+    validateComfyWorkflowMock.mockResolvedValue(wf)
+    validateLinkTopologyMock.mockReturnValue([])
+    let received: ComfyWorkflowJSON | undefined
+    repairLinksMock.mockImplementation((g: ComfyWorkflowJSON) => {
+      received = g
+      return repairResult(g)
+    })
+
+    const { validateWorkflow } = useWorkflowValidation()
+    await validateWorkflow(wf)
+
+    expect(received).not.toBe(wf)
+  })
+
+  it('silent option suppresses toasts but still validates', async () => {
+    const wf = makeWorkflow()
+    validateComfyWorkflowMock.mockResolvedValue(wf)
+    validateLinkTopologyMock.mockReturnValue([
+      { kind: 'missing-origin-node', link: makeLink(1) }
+    ])
+    repairLinksMock.mockImplementation((g) =>
+      repairResult(g, { fixed: true, patched: 1, deleted: 0 })
+    )
+
+    const { validateWorkflow } = useWorkflowValidation()
+    const out = await validateWorkflow(wf, { silent: true })
+
+    expect(out.graphData).not.toBeNull()
+    expect(toastAddMock).not.toHaveBeenCalled()
+    expect(toastAddAlertMock).not.toHaveBeenCalled()
+  })
+})
diff --git a/src/platform/workflow/validation/composables/useWorkflowValidation.ts b/src/platform/workflow/validation/composables/useWorkflowValidation.ts
index 064972dc6b5..3fc5f8546a3 100644
--- a/src/platform/workflow/validation/composables/useWorkflowValidation.ts
+++ b/src/platform/workflow/validation/composables/useWorkflowValidation.ts
@@ -1,60 +1,156 @@
-import type { ISerialisedGraph } from '@/lib/litegraph/src/types/serialisation'
+import {
+  LinkRepairAbortedError,
+  describeTopologyError,
+  repairLinks,
+  validateLinkTopology
+} from '@comfyorg/workflow-validation'
+import type {
+  SerialisedGraph,
+  TopologyError
+} from '@comfyorg/workflow-validation'
+import { useI18n } from 'vue-i18n'
+
 import { useToastStore } from '@/platform/updates/common/toastStore'
 import type { ComfyWorkflowJSON } from '@/platform/workflow/validation/schemas/workflowSchema'
 import { validateComfyWorkflow } from '@/platform/workflow/validation/schemas/workflowSchema'
-import { fixBadLinks } from '@/utils/linkFixer'
+import { clone } from '@/scripts/utils'
 
 interface ValidationResult {
   graphData: ComfyWorkflowJSON | null
 }
 
+const TOPOLOGY_TOAST_LIMIT = 5
+
 export function useWorkflowValidation() {
   const toastStore = useToastStore()
+  const { t } = useI18n()
+
+  function linkParams(error: TopologyError): Record<string, unknown> {
+    return {
+      linkId: error.link.linkId,
+      originId: error.link.originId,
+      originSlot: error.link.originSlot,
+      targetId: error.link.targetId,
+      targetSlot: error.link.targetSlot
+    }
+  }
+
+  function localizeTopologyError(error: TopologyError): string {
+    const base = linkParams(error)
+    const tuple = t('validation.topology.tuple', base)
+    const params = { ...base, tuple }
+    switch (error.kind) {
+      case 'missing-origin-node':
+        return t('validation.topology.missingOriginNode', params)
+      case 'missing-target-node':
+        return t('validation.topology.missingTargetNode', params)
+      case 'origin-slot-out-of-bounds':
+        return t(
+          'validation.topology.originSlotOutOfBounds',
+          error.originSlotCount,
+          { named: { ...params, count: error.originSlotCount } }
+        )
+      case 'target-slot-out-of-bounds':
+        return t(
+          'validation.topology.targetSlotOutOfBounds',
+          error.targetSlotCount,
+          { named: { ...params, count: error.targetSlotCount } }
+        )
+      case 'origin-link-not-listed':
+        return t('validation.topology.originLinkNotListed', params)
+      case 'target-link-mismatch':
+        return t('validation.topology.targetLinkMismatch', {
+          ...params,
+          actualLink: String(error.actualLink)
+        })
+    }
+  }
+
+  function summariseTopologyErrors(errors: TopologyError[]): string {
+    const lines = errors
+      .slice(0, TOPOLOGY_TOAST_LIMIT)
+      .map(localizeTopologyError)
+    if (errors.length > TOPOLOGY_TOAST_LIMIT) {
+      lines.push(
+        t('validation.topology.overflow', {
+          count: errors.length - TOPOLOGY_TOAST_LIMIT
+        })
+      )
+    }
+    return lines.join('\n')
+  }
+
+  function reportTopology(errors: TopologyError[], silent: boolean) {
+    if (silent || errors.length === 0) return
+    for (const e of errors) console.warn('[topology]', describeTopologyError(e))
+    toastStore.add({
+      severity: 'warn',
+      summary: t('validation.topology.invalidLinks', errors.length, {
+        named: { count: errors.length }
+      }),
+      detail: summariseTopologyErrors(errors),
+      life: 10_000
+    })
+  }
 
   function tryFixLinks(
     graphData: ComfyWorkflowJSON,
     options: { silent?: boolean } = {}
-  ) {
+  ): { graph: ComfyWorkflowJSON; aborted: boolean } {
     const { silent = false } = options
+    const topologyErrors = validateLinkTopology(graphData as SerialisedGraph)
+    reportTopology(topologyErrors, silent)
 
-    // Collect all logs in an array
+    const repairTarget = clone(graphData)
     const logs: string[] = []
-    // Then validate and fix links if schema validation passed
-    const linkValidation = fixBadLinks(graphData as ISerialisedGraph, {
-      fix: true,
-      silent,
-      logger: {
-        log: (...args: unknown[]) => {
-          logs.push(args.join(' '))
+    try {
+      const linkValidation = repairLinks(repairTarget as SerialisedGraph, {
+        fix: true,
+        silent,
+        logger: {
+          log: (...args: unknown[]) => logs.push(args.join(' '))
         }
-      }
-    })
-
-    if (!silent && logs.length > 0) {
-      toastStore.add({
-        severity: 'warn',
-        summary: 'Workflow Validation',
-        detail: logs.join('\n')
       })
-    }
 
-    // If links were fixed, notify the user
-    if (linkValidation.fixed) {
-      if (!silent) {
+      if (!silent && logs.length > 0) {
+        toastStore.add({
+          severity: 'warn',
+          summary: t('validation.topology.validationSummary'),
+          detail: logs.join('\n')
+        })
+      }
+      if (linkValidation.fixed && !silent) {
         toastStore.add({
           severity: 'success',
-          summary: 'Workflow Links Fixed',
-          detail: `Fixed ${linkValidation.patched} node connections and removed ${linkValidation.deleted} invalid links.`
+          summary: t('validation.topology.linksFixedSummary'),
+          detail: t('validation.topology.linksFixedDetail', {
+            patched: linkValidation.patched,
+            deleted: linkValidation.deleted
+          })
         })
       }
+      return {
+        graph: linkValidation.graph as ComfyWorkflowJSON,
+        aborted: false
+      }
+    } catch (err: unknown) {
+      if (err instanceof LinkRepairAbortedError) {
+        if (!silent) {
+          toastStore.add({
+            severity: 'error',
+            summary: t('validation.topology.abortedSummary'),
+            detail: localizeTopologyError(err.topologyError),
+            life: 15_000
+          })
+        }
+        console.error('[linkFixer aborted]', err.topologyError, err)
+        return { graph: graphData, aborted: true }
+      }
+      console.error(err)
+      throw err
     }
-
-    return linkValidation.graph
   }
 
-  /**
-   * Validates a workflow, including link validation and schema validation
-   */
   async function validateWorkflow(
     graphData: ComfyWorkflowJSON,
     options: {
@@ -63,32 +159,16 @@ export function useWorkflowValidation() {
   ): Promise<ValidationResult> {
     const { silent = false } = options
 
-    let validatedData: ComfyWorkflowJSON | null = null
+    const validatedGraphData = await validateComfyWorkflow(graphData, (err) => {
+      if (!silent) toastStore.addAlert(err)
+    })
 
-    // First do schema validation
-    const validatedGraphData = await validateComfyWorkflow(
-      graphData,
-      /* onError=*/ (err) => {
-        if (!silent) {
-          toastStore.addAlert(err)
-        }
-      }
-    )
-
-    if (validatedGraphData) {
-      try {
-        validatedData = tryFixLinks(validatedGraphData, {
-          silent
-        }) as ComfyWorkflowJSON
-      } catch (err) {
-        // Link fixer itself is throwing an error
-        console.error(err)
-      }
+    if (!validatedGraphData) {
+      return { graphData: null }
     }
 
-    return {
-      graphData: validatedData
-    }
+    const { graph, aborted } = tryFixLinks(validatedGraphData, { silent })
+    return { graphData: aborted ? null : graph }
   }
 
   return {
diff --git a/src/utils/linkFixer.test.ts b/src/utils/linkFixer.test.ts
index 67df6668cdb..1185328e6a0 100644
--- a/src/utils/linkFixer.test.ts
+++ b/src/utils/linkFixer.test.ts
@@ -1,3 +1,4 @@
+import { fixBadLinks } from '@comfyorg/workflow-validation'
 import { describe, expect, it, vi } from 'vitest'
 
 import type { SerialisedLLinkArray } from '@/lib/litegraph/src/LLink'
@@ -6,8 +7,6 @@ import type {
   ISerialisedNode
 } from '@/lib/litegraph/src/types/serialisation'
 
-import { fixBadLinks } from './linkFixer'
-
 type SerialisedInput = NonNullable<ISerialisedNode['inputs']>[number]
 type SerialisedOutput = NonNullable<ISerialisedNode['outputs']>[number]
 
diff --git a/tsconfig.json b/tsconfig.json
index 23162bafc83..e58cbcfd9cf 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -27,6 +27,10 @@
       ],
       "@/utils/networkUtil": [
         "./packages/shared-frontend-utils/src/networkUtil.ts"
+      ],
+      "@/utils/linkFixer": ["./packages/workflow-validation/src/linkRepair.ts"],
+      "@/platform/workflow/validation/schemas/workflowSchema": [
+        "./packages/workflow-validation/src/workflowSchema.ts"
       ]
     },
     "typeRoots": ["src/types", "node_modules/@types", "./node_modules"],
diff --git a/vite.config.mts b/vite.config.mts
index a95d5e4dc56..91032e30510 100644
--- a/vite.config.mts
+++ b/vite.config.mts
@@ -634,6 +634,9 @@ export default defineConfig({
       '@/utils/formatUtil': '/packages/shared-frontend-utils/src/formatUtil.ts',
       '@/utils/networkUtil':
         '/packages/shared-frontend-utils/src/networkUtil.ts',
+      '@/utils/linkFixer': '/packages/workflow-validation/src/linkRepair.ts',
+      '@/platform/workflow/validation/schemas/workflowSchema':
+        '/packages/workflow-validation/src/workflowSchema.ts',
       '@': '/src'
     }
   },