From 74b027c41af3c26e1bbe6883f549b774b1706e05 Mon Sep 17 00:00:00 2001
From: wangxiaolei <fatelei@gmail.com>
Date: Wed, 4 Feb 2026 17:33:41 +0800
Subject: [PATCH] fix: fix mcp output schema is union type frontend crash
 (#31779)

Co-authored-by: Stephen Zhou <38493346+hyoban@users.noreply.github.com>
---
 .../workflow/nodes/tool/use-config.ts         | 22 +++++++++----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/web/app/components/workflow/nodes/tool/use-config.ts b/web/app/components/workflow/nodes/tool/use-config.ts
index 7e4594f4f2..87e9186008 100644
--- a/web/app/components/workflow/nodes/tool/use-config.ts
+++ b/web/app/components/workflow/nodes/tool/use-config.ts
@@ -1,6 +1,7 @@
 import type { ToolNodeType, ToolVarInputs } from './types'
 import type { InputVar } from '@/app/components/workflow/types'
 import { useBoolean } from 'ahooks'
+import { capitalize } from 'es-toolkit/string'
 import { produce } from 'immer'
 import { useCallback, useEffect, useMemo, useState } from 'react'
 import { useTranslation } from 'react-i18next'
@@ -25,6 +26,12 @@ import {
 } from '@/service/use-tools'
 import { canFindTool } from '@/utils'
 import { useWorkflowStore } from '../../store'
+import { normalizeJsonSchemaType } from './output-schema-utils'
+
+const formatDisplayType = (output: Record<string, unknown>): string => {
+  const normalizedType = normalizeJsonSchemaType(output) || 'Unknown'
+  return capitalize(normalizedType)
+}
 
 const useConfig = (id: string, payload: ToolNodeType) => {
   const workflowStore = useWorkflowStore()
@@ -247,20 +254,13 @@ const useConfig = (id: string, payload: ToolNodeType) => {
         })
       }
       else {
+        const normalizedType = normalizeJsonSchemaType(output)
         res.push({
           name: outputKey,
           type:
-            output.type === 'array'
-              ? `Array[${output.items?.type
-                ? output.items.type.slice(0, 1).toLocaleUpperCase()
-                + output.items.type.slice(1)
-                : 'Unknown'
-              }]`
-              : `${output.type
-                ? output.type.slice(0, 1).toLocaleUpperCase()
-                + output.type.slice(1)
-                : 'Unknown'
-              }`,
+            normalizedType === 'array'
+              ? `Array[${output.items ? formatDisplayType(output.items) : 'Unknown'}]`
+              : formatDisplayType(output),
           description: output.description,
         })
       }