fix: relax MCP tool JSON Schema Zod validation to handle non-standard types (#6455)

* fix: relax MCP tool JSON Schema Zod validation to accept any type values

MCP servers may return JSON Schema with type values outside the
standard 6 types. Use z.any() for type and items fields to avoid
500 errors on /api/core/app/mcpTools/getTools.

- Remove SchemaInputValueTypeSchema enum and SchemaInputValueType
- Remove unnecessary .passthrough()
- Use plain string type for function parameters

Fixes #6451

* fix: mcp adapt

---------

Co-authored-by: c121914yu <yucongcong_test@163.com>

document/content/docs/toc.mdx

@@ -121,6 +121,7 @@ description: FastGPT 文档目录
 - [/docs/upgrading/4-14/41451](/docs/upgrading/4-14/41451)
 - [/docs/upgrading/4-14/4146](/docs/upgrading/4-14/4146)
 - [/docs/upgrading/4-14/4147](/docs/upgrading/4-14/4147)
+- [/docs/upgrading/4-14/4148](/docs/upgrading/4-14/4148)
 - [/docs/upgrading/4-8/40](/docs/upgrading/4-8/40)
 - [/docs/upgrading/4-8/41](/docs/upgrading/4-8/41)
 - [/docs/upgrading/4-8/42](/docs/upgrading/4-8/42)

document/content/docs/upgrading/4-14/4148.mdx

@@ -0,0 +1,18 @@
+---
+title: 'V4.14.8(进行中)'
+description: 'FastGPT V4.14.8 更新说明'
+---
+
+
+## 🚀 新增内容
+
+
+
+## ⚙️ 优化
+
+1. 兼容 MCP 中 JSON Schema type 类型不在枚举类型里。
+
+## 🐛 修复
+
+1. 新 SDK 兼容：连续调用同一个 MCP 服务时，多次连接导致报错。
+

document/content/docs/upgrading/4-14/meta.json

@@ -1,5 +1,5 @@
 {
   "title": "4.14.x",
   "description": "",
-  "pages": ["4147", "4146", "41451", "4145", "4144", "4143", "4142", "4141", "4140"]
+  "pages": ["4148", "4147", "4146", "41451", "4145", "4144", "4143", "4142", "4141", "4140"]
 }

document/data/doc-last-modified.json

@@ -205,4 +205,4 @@
   "document/content/docs/use-cases/external-integration/openapi.mdx": "2026-02-12T18:45:30+08:00",
   "document/content/docs/use-cases/external-integration/wecom.mdx": "2025-12-10T20:07:05+08:00",
   "document/content/docs/use-cases/index.mdx": "2025-07-24T14:23:04+08:00"
-}
+}

packages/global/core/app/jsonschema.ts

@@ -8,36 +8,26 @@ import type { OpenApiJsonSchema } from './tool/httpTool/type';
 import { i18nT } from '../../../web/i18n/utils';
 import z from 'zod';
 
-const SchemaInputValueTypeSchema = z.enum([
-  'string',
-  'number',
-  'integer',
-  'boolean',
-  'array',
-  'object'
-]);
-type SchemaInputValueType = z.infer<typeof SchemaInputValueTypeSchema>;
-
 export const JsonSchemaPropertiesItemSchema = z.object({
   description: z.string().optional(),
   'x-tool-description': z.string().optional(),
-  type: SchemaInputValueTypeSchema,
+  type: z.any(),
   enum: z.array(z.string()).optional(),
   minimum: z.number().optional(),
   maximum: z.number().optional(),
-  items: z.object({ type: SchemaInputValueTypeSchema }).optional()
+  items: z.any().optional() // Array 时候有
 });
 export type JsonSchemaPropertiesItemType = z.infer<typeof JsonSchemaPropertiesItemSchema>;
 
 export const JSONSchemaInputTypeSchema = z.object({
-  type: SchemaInputValueTypeSchema,
+  type: z.any().optional(),
   properties: z.record(z.string(), JsonSchemaPropertiesItemSchema).optional(),
   required: z.array(z.string()).optional()
 });
 export type JSONSchemaInputType = z.infer<typeof JSONSchemaInputTypeSchema>;
 
 export const JSONSchemaOutputTypeSchema = z.object({
-  type: SchemaInputValueTypeSchema,
+  type: z.any().optional(),
   properties: z.record(z.string(), JsonSchemaPropertiesItemSchema).optional(),
   required: z.array(z.string()).optional()
 });
@@ -47,21 +37,21 @@ export const getNodeInputTypeFromSchemaInputType = ({
   type,
   arrayItems
 }: {
-  type: SchemaInputValueType;
+  type: string;
-  arrayItems?: { type: SchemaInputValueType };
+  arrayItems?: { type: string };
 }) => {
   if (type === 'string') return WorkflowIOValueTypeEnum.string;
-  if (type === 'number') return WorkflowIOValueTypeEnum.number;
+  if (type === 'number' || type === 'integer') return WorkflowIOValueTypeEnum.number;
-  if (type === 'integer') return WorkflowIOValueTypeEnum.number;
   if (type === 'boolean') return WorkflowIOValueTypeEnum.boolean;
   if (type === 'object') return WorkflowIOValueTypeEnum.object;
 
+  if (type !== 'array') return WorkflowIOValueTypeEnum.any;
+
   if (!arrayItems) return WorkflowIOValueTypeEnum.arrayAny;
 
   const itemType = arrayItems.type;
   if (itemType === 'string') return WorkflowIOValueTypeEnum.arrayString;
-  if (itemType === 'number') return WorkflowIOValueTypeEnum.arrayNumber;
+  if (itemType === 'number' || itemType === 'integer') return WorkflowIOValueTypeEnum.arrayNumber;
-  if (itemType === 'integer') return WorkflowIOValueTypeEnum.arrayNumber;
   if (itemType === 'boolean') return WorkflowIOValueTypeEnum.arrayBoolean;
   if (itemType === 'object') return WorkflowIOValueTypeEnum.arrayObject;
 

packages/service/core/app/mcp.ts

@@ -17,6 +17,7 @@ export class MCPClient {
   private client: Client;
   private url: string;
   private headers: Record<string, any> = {};
+  private connectionPromise: Promise<Client> | null = null;
 
   constructor(config: { url: string; headers: Record<string, any> }) {
     this.url = config.url;
@@ -28,6 +29,28 @@ export class MCPClient {
   }
 
   private async getConnection(): Promise<Client> {
+    if (this.connectionPromise) {
+      return this.connectionPromise;
+    }
+
+    this.connectionPromise = this.doConnect().catch((error) => {
+      // 连接失败时清除缓存，允许下次重试
+      this.connectionPromise = null;
+      throw error;
+    });
+
+    this.client.onerror = (error) => {
+      logger.error('MCP client connection error', { url: this.url, error });
+      this.connectionPromise = null;
+    };
+    this.client.onclose = () => {
+      this.connectionPromise = null;
+    };
+
+    return this.connectionPromise;
+  }
+
+  private async doConnect(): Promise<Client> {
     try {
       const transport = new StreamableHTTPClientTransport(new URL(this.url), {
         requestInit: {
@@ -37,6 +60,7 @@ export class MCPClient {
       await this.client.connect(transport);
       return this.client;
     } catch (error) {
+      logger.debug('StreamableHTTP connect failed, falling back to SSE', { url: this.url, error });
       await this.client.connect(
         new SSEClientTransport(new URL(this.url), {
           requestInit: {
@@ -72,6 +96,7 @@ export class MCPClient {
 
   // 内部方法：关闭连接
   async closeConnection() {
+    this.connectionPromise = null;
     try {
       await retryFn(() => this.client.close(), 3);
       logger.debug('MCP client connection closed', { url: this.url });