v2: cf workers fix (modelcontextprotocol#1843)

Co-authored-by: Felix Weinberger <3823880+felixweinberger@users.noreply.github.com>

Author: KKonstantinov

docs/migration-SKILL.md

@@ -480,7 +480,10 @@ new McpServer(
 new McpServer({ name: 'server', version: '1.0.0' }, {});
 ```
 
-Access validators via `_shims` export: `import { DefaultJsonSchemaValidator } from '@modelcontextprotocol/server/_shims';`
+Access validators explicitly:
+- Runtime-aware default: `import { DefaultJsonSchemaValidator } from '@modelcontextprotocol/server/_shims';`
+- AJV (Node.js): `import { AjvJsonSchemaValidator } from '@modelcontextprotocol/server';`
+- CF Worker: `import { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/server/validators/cf-worker';`
 
 ## 15. Migration Steps (apply in this order)
 

docs/migration.md

@@ -835,7 +835,8 @@ This means Cloudflare Workers users no longer need to explicitly pass the valida
 **Before (v1) - Cloudflare Workers required explicit configuration:**
 
 ```typescript
-import { McpServer, CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/server';
+import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/sdk/validation/cfworker';
 
 const server = new McpServer(
     { name: 'my-server', version: '1.0.0' },
@@ -858,12 +859,15 @@ const server = new McpServer(
 );
 ```
 
-You can still explicitly override the validator if needed. The validators are available via the `_shims` export:
+You can still explicitly override the validator if needed:
 
 ```typescript
+// Runtime-aware default (auto-selects AjvJsonSchemaValidator or CfWorkerJsonSchemaValidator)
 import { DefaultJsonSchemaValidator } from '@modelcontextprotocol/server/_shims';
-// or
-import { AjvJsonSchemaValidator, CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/server';
+
+// Specific validators
+import { AjvJsonSchemaValidator } from '@modelcontextprotocol/server';
+import { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/server/validators/cf-worker';
 ```
 
 ## Unchanged APIs

packages/client/package.json

@@ -24,6 +24,10 @@
             "types": "./dist/index.d.mts",
             "import": "./dist/index.mjs"
         },
+        "./validators/cf-worker": {
+            "types": "./dist/validators/cfWorker.d.mts",
+            "import": "./dist/validators/cfWorker.mjs"
+        },
         "./_shims": {
             "workerd": {
                 "types": "./dist/shimsWorkerd.d.mts",
@@ -67,14 +71,6 @@
         "pkce-challenge": "catalog:runtimeShared",
         "zod": "catalog:runtimeShared"
     },
-    "peerDependencies": {
-        "@cfworker/json-schema": "catalog:runtimeShared"
-    },
-    "peerDependenciesMeta": {
-        "@cfworker/json-schema": {
-            "optional": true
-        }
-    },
     "devDependencies": {
         "@modelcontextprotocol/core": "workspace:^",
         "@modelcontextprotocol/tsconfig": "workspace:^",

packages/client/src/client/client.ts

@@ -162,7 +162,7 @@ export type ClientOptions = ProtocolOptions & {
      * The validator is used to validate structured content returned by tools
      * against their declared output schemas.
      *
-     * @default {@linkcode DefaultJsonSchemaValidator} ({@linkcode index.AjvJsonSchemaValidator | AjvJsonSchemaValidator} on Node.js, {@linkcode index.CfWorkerJsonSchemaValidator | CfWorkerJsonSchemaValidator} on Cloudflare Workers)
+     * @default {@linkcode DefaultJsonSchemaValidator} ({@linkcode index.AjvJsonSchemaValidator | AjvJsonSchemaValidator} on Node.js, `CfWorkerJsonSchemaValidator` on Cloudflare Workers)
      */
     jsonSchemaValidator?: jsonSchemaValidator;
 

packages/client/src/validators/cfWorker.ts

@@ -0,0 +1,10 @@
+/**
+ * Cloudflare Workers JSON Schema validator, available as a sub-path export.
+ *
+ * @example
+ * ```ts
+ * import { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/client/validators/cf-worker';
+ * ```
+ */
+export { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/core';
+export type { CfWorkerSchemaDraft } from '@modelcontextprotocol/core';

packages/client/tsdown.config.ts

@@ -4,7 +4,7 @@ export default defineConfig({
     failOnWarn: 'ci-only',
     // 1. Entry Points
     //    Directly matches package.json include/exclude globs
-    entry: ['src/index.ts', 'src/shimsNode.ts', 'src/shimsWorkerd.ts', 'src/shimsBrowser.ts'],
+    entry: ['src/index.ts', 'src/shimsNode.ts', 'src/shimsWorkerd.ts', 'src/shimsBrowser.ts', 'src/validators/cfWorker.ts'],
 
     // 2. Output Configuration
     format: ['esm'],

packages/core/src/exports/public/index.ts

@@ -137,7 +137,6 @@ export { InMemoryTaskMessageQueue, InMemoryTaskStore } from '../../experimental/
 export type { StandardSchemaWithJSON } from '../../util/standardSchema.js';
 export { AjvJsonSchemaValidator } from '../../validators/ajvProvider.js';
 export type { CfWorkerSchemaDraft } from '../../validators/cfWorkerProvider.js';
-export { CfWorkerJsonSchemaValidator } from '../../validators/cfWorkerProvider.js';
 // fromJsonSchema is intentionally NOT exported here — the server and client packages
 // provide runtime-aware wrappers that default to the appropriate validator via _shims.
 export type { JsonSchemaType, JsonSchemaValidator, jsonSchemaValidator, JsonSchemaValidatorResult } from '../../validators/types.js';

packages/core/src/index.ts

@@ -28,12 +28,11 @@ export * from './validators/fromJsonSchema.js';
  * Choose a validator based on your runtime environment:
  *
  * - {@linkcode AjvJsonSchemaValidator}: Best for Node.js (default, fastest)
- *   Import from: @modelcontextprotocol/sdk/validators/ajv
- *   Requires peer dependencies: ajv, ajv-formats
+ *   Bundled — no additional dependencies required.
  *
  * - {@linkcode CfWorkerJsonSchemaValidator}: Best for edge runtimes
- *   Import from: @modelcontextprotocol/sdk/validators/cfworker
- *   Requires peer dependency: @cfworker/json-schema
+ *   Import from: `@modelcontextprotocol/server/validators/cf-worker` or `@modelcontextprotocol/client/validators/cf-worker`
+ *   Bundled — no additional dependencies required.
  *
  * @example For Node.js with AJV
  * ```ts source="./index.examples.ts#validation_ajv"

packages/core/src/validators/ajvProvider.ts

@@ -33,7 +33,7 @@ function createDefaultAjvInstance(): Ajv {
  * const validator = new AjvJsonSchemaValidator(ajv);
  * ```
  *
- * @see {@linkcode CfWorkerJsonSchemaValidator} for an edge-runtime-compatible alternative
+ * @see `CfWorkerJsonSchemaValidator` for an edge-runtime-compatible alternative (import from `@modelcontextprotocol/server/validators/cf-worker` or `@modelcontextprotocol/client/validators/cf-worker`)
  */
 export class AjvJsonSchemaValidator implements jsonSchemaValidator {
     private _ajv: Ajv;

packages/server/package.json

@@ -24,6 +24,10 @@
             "types": "./dist/index.d.mts",
             "import": "./dist/index.mjs"
         },
+        "./validators/cf-worker": {
+            "types": "./dist/validators/cfWorker.d.mts",
+            "import": "./dist/validators/cfWorker.mjs"
+        },
         "./_shims": {
             "workerd": {
                 "types": "./dist/shimsWorkerd.d.mts",
@@ -62,14 +66,6 @@
     "dependencies": {
         "zod": "catalog:runtimeShared"
     },
-    "peerDependencies": {
-        "@cfworker/json-schema": "catalog:runtimeShared"
-    },
-    "peerDependenciesMeta": {
-        "@cfworker/json-schema": {
-            "optional": true
-        }
-    },
     "devDependencies": {
         "@cfworker/json-schema": "catalog:runtimeShared",
         "@eslint/js": "catalog:devTools",