fix: Replace non-standard enumNames with standard oneOf in EnumSchema

README.md

@@ -1040,8 +1040,11 @@ server.tool(
               type: "string",
               title: "Date flexibility",
               description: "How flexible are your dates?",
-              enum: ["next_day", "same_week", "next_week"],
-              enumNames: ["Next day", "Same week", "Next week"]
+              oneOf: [
+                { const: "next_day", title: "Next day" },
+                { const: "same_week", title: "Same week" },
+                { const: "next_week", title: "Next week" }
+              ],
             }
           },
           required: ["checkAlternatives"]

package.json

@@ -50,7 +50,7 @@
     "client": "tsx src/cli.ts client"
   },
   "dependencies": {
-    "ajv": "^6.12.6",
+    "ajv": "^8.17.1",
     "content-type": "^1.0.5",
     "cors": "^2.8.5",
     "cross-spawn": "^7.0.5",

src/client/index.ts

@@ -43,7 +43,7 @@ import {
   ErrorCode,
   McpError,
 } from "../types.js";
-import Ajv from "ajv";
+import { Ajv } from 'ajv';
 import type { ValidateFunction } from "ajv";
 
 export type ClientOptions = ProtocolOptions & {
@@ -92,7 +92,7 @@ export class Client<
   private _capabilities: ClientCapabilities;
   private _instructions?: string;
   private _cachedToolOutputValidators: Map<string, ValidateFunction> = new Map();
-  private _ajv: InstanceType<typeof Ajv>;
+  private _ajv: Ajv;
 
   /**
    * Initializes this client with the given name and version information.

src/examples/client/simpleStreamableHttp.ts

@@ -20,7 +20,7 @@ import {
   ReadResourceResultSchema,
 } from '../../types.js';
 import { getDisplayName } from '../../shared/metadataUtils.js';
-import Ajv from "ajv";
+import { Ajv } from 'ajv';
 
 // Create readline interface for user input
 const readline = createInterface({
@@ -373,7 +373,7 @@ async function connect(url?: string): Promise<void> {
         if (!isValid) {
           console.log('❌ Validation errors:');
           validate.errors?.forEach(error => {
-            console.log(`  - ${error.dataPath || 'root'}: ${error.message}`);
+            console.log(`  - ${error.instancePath || 'root'}: ${error.message}`);
           });
 
           if (attempts < maxAttempts) {

src/examples/server/simpleStreamableHttp.ts

@@ -141,8 +141,11 @@ const getServer = () => {
                 type: 'string',
                 title: 'Theme',
                 description: 'Choose your preferred theme',
-                enum: ['light', 'dark', 'auto'],
-                enumNames: ['Light', 'Dark', 'Auto'],
+                oneOf: [
+                  { const: 'light', title: 'Light' },
+                  { const: 'dark', title: 'Dark' },
+                  { const: 'auto', title: 'Auto' }
+                ],
               },
               notifications: {
                 type: 'boolean',
@@ -154,8 +157,11 @@ const getServer = () => {
                 type: 'string',
                 title: 'Notification Frequency',
                 description: 'How often would you like notifications?',
-                enum: ['daily', 'weekly', 'monthly'],
-                enumNames: ['Daily', 'Weekly', 'Monthly'],
+                oneOf: [
+                  { const: 'daily', title: 'Daily' },
+                  { const: 'weekly', title: 'Weekly' },
+                  { const: 'monthly', title: 'Monthly' }
+                ],
               },
             },
             required: ['theme'],

src/server/index.ts

@@ -33,7 +33,7 @@ import {
   ServerResult,
   SUPPORTED_PROTOCOL_VERSIONS,
 } from "../types.js";
-import Ajv from "ajv";
+import { Ajv } from 'ajv';
 
 export type ServerOptions = ProtocolOptions & {
   /**
@@ -85,6 +85,7 @@ export class Server<
   private _clientVersion?: Implementation;
   private _capabilities: ServerCapabilities;
   private _instructions?: string;
+  private _ajv: Ajv;
 
   /**
    * Callback for when initialization has fully completed (i.e., the client has sent an `initialized` notification).
@@ -101,6 +102,7 @@ export class Server<
     super(options);
     this._capabilities = options?.capabilities ?? {};
     this._instructions = options?.instructions;
+    this._ajv = new Ajv({ code: { source: false } });
 
     this.setRequestHandler(InitializeRequestSchema, (request) =>
       this._oninitialize(request),
@@ -323,15 +325,13 @@ export class Server<
     // Validate the response content against the requested schema if action is "accept"
     if (result.action === "accept" && result.content) {
       try {
-        const ajv = new Ajv();
-
-        const validate = ajv.compile(params.requestedSchema);
+        const validate = this._ajv.compile(params.requestedSchema);
         const isValid = validate(result.content);
 
         if (!isValid) {
           throw new McpError(
             ErrorCode.InvalidParams,
-            `Elicitation response content does not match requested schema: ${ajv.errorsText(validate.errors)}`,
+            `Elicitation response content does not match requested schema: ${this._ajv.errorsText(validate.errors)}`,
           );
         }
       } catch (error) {

src/server/mcp.test.ts

@@ -4119,8 +4119,11 @@ describe("elicitInput()", () => {
                   type: "string",
                   title: "Date flexibility",
                   description: "How flexible are your dates?",
-                  enum: ["next_day", "same_week", "next_week"],
-                  enumNames: ["Next day", "Same week", "Next week"]
+                  oneOf: [
+                    { const: "next_day", title: "Next day" },
+                    { const: "same_week", title: "Same week" },
+                    { const: "next_week", title: "Next week" }
+                  ],
                 }
               },
               required: ["checkAlternatives"]

src/types.ts

@@ -1212,8 +1212,10 @@ export const EnumSchemaSchema = z
     type: z.literal("string"),
     title: z.optional(z.string()),
     description: z.optional(z.string()),
-    enum: z.array(z.string()),
-    enumNames: z.optional(z.array(z.string())),
+    oneOf: z.array(z.object({
+      const: z.string(),
+      title: z.string()
+    })),
   })
   .passthrough();