fix(core): stop bundling @cfworker/json-schema into the main barrel

CfWorkerJsonSchemaValidator was re-exported from the core internal barrel,
pulling the optional-peer @cfworker/json-schema static import into every Node
consumer's bundle. Move it to a dedicated core/validators/cfWorker subpath;
the workerd/browser _shims and the public /validators/cf-worker subpath import
from there instead. Main index.mjs no longer references the package.

Author: felixweinberger

.changeset/cfworker-out-of-barrel.md

@@ -0,0 +1,6 @@
+---
+'@modelcontextprotocol/server': patch
+'@modelcontextprotocol/client': patch
+---
+
+Stop bundling `@cfworker/json-schema` into the main package barrel. Previously `CfWorkerJsonSchemaValidator` was re-exported from the core internal barrel, so tsdown inlined the `@cfworker/json-schema` dev dependency into every consumer's bundle even when it was never used. The validator is now reachable only via the `_shims` conditional (workerd/browser) and the explicit `@modelcontextprotocol/{server,client}/validators/cf-worker` subpath, so consumers that don't opt into it no longer ship that code. No public API change.

packages/client/src/shimsBrowser.ts

@@ -3,7 +3,7 @@
  *
  * This file is selected via package.json export conditions when running in a browser.
  */
-export { CfWorkerJsonSchemaValidator as DefaultJsonSchemaValidator } from '@modelcontextprotocol/core';
+export { CfWorkerJsonSchemaValidator as DefaultJsonSchemaValidator } from '@modelcontextprotocol/core/validators/cfWorker';
 
 /**
  * Whether `fetch()` may throw `TypeError` due to CORS. Only true in browser contexts

packages/client/src/shimsWorkerd.ts

@@ -3,7 +3,7 @@
  *
  * This file is selected via package.json export conditions when running in workerd.
  */
-export { CfWorkerJsonSchemaValidator as DefaultJsonSchemaValidator } from '@modelcontextprotocol/core';
+export { CfWorkerJsonSchemaValidator as DefaultJsonSchemaValidator } from '@modelcontextprotocol/core/validators/cfWorker';
 
 /**
  * Whether `fetch()` may throw `TypeError` due to CORS. CORS is a browser-only concept —

packages/client/src/validators/cfWorker.ts

@@ -6,5 +6,5 @@
  * import { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/client/validators/cf-worker';
  * ```
  */
-export { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/core';
-export type { CfWorkerSchemaDraft } from '@modelcontextprotocol/core';
+export type { CfWorkerSchemaDraft } from '@modelcontextprotocol/core/validators/cfWorker';
+export { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/core/validators/cfWorker';

packages/client/tsconfig.json

@@ -7,6 +7,9 @@
             "*": ["./*"],
             "@modelcontextprotocol/core": ["./node_modules/@modelcontextprotocol/core/src/index.ts"],
             "@modelcontextprotocol/core/public": ["./node_modules/@modelcontextprotocol/core/src/exports/public/index.ts"],
+            "@modelcontextprotocol/core/validators/cfWorker": [
+                "./node_modules/@modelcontextprotocol/core/src/validators/cfWorkerProvider.ts"
+            ],
             "@modelcontextprotocol/test-helpers": ["./node_modules/@modelcontextprotocol/test-helpers/src/index.ts"],
             "@modelcontextprotocol/client/_shims": ["./src/shimsNode.ts"]
         }

packages/client/tsdown.config.ts

@@ -26,7 +26,8 @@ export default defineConfig({
             baseUrl: '.',
             paths: {
                 '@modelcontextprotocol/core': ['../core/src/index.ts'],
-                '@modelcontextprotocol/core/public': ['../core/src/exports/public/index.ts']
+                '@modelcontextprotocol/core/public': ['../core/src/exports/public/index.ts'],
+                '@modelcontextprotocol/core/validators/cfWorker': ['../core/src/validators/cfWorkerProvider.ts']
             }
         }
     },

packages/core/package.json

@@ -32,6 +32,10 @@
         "./public": {
             "types": "./src/exports/public/index.ts",
             "import": "./src/exports/public/index.ts"
+        },
+        "./validators/cfWorker": {
+            "types": "./src/validators/cfWorkerProvider.ts",
+            "import": "./src/validators/cfWorkerProvider.ts"
         }
     },
     "scripts": {

packages/core/src/index.ts

@@ -19,7 +19,11 @@ export * from './util/standardSchema.js';
 // experimental exports
 export * from './experimental/index.js';
 export * from './validators/ajvProvider.js';
-export * from './validators/cfWorkerProvider.js';
+// cfWorkerProvider is intentionally NOT re-exported here: it statically imports
+// `@cfworker/json-schema` (an optional peer), and bundling it into the main barrel
+// would force that import on all Node consumers. Import via `@modelcontextprotocol/core/validators/cfWorker`
+// (used by the workerd/browser `_shims` and the public `/validators/cf-worker` subpaths).
+export type { CfWorkerSchemaDraft } from './validators/cfWorkerProvider.js';
 export * from './validators/fromJsonSchema.js';
 /**
  * JSON Schema validation
@@ -30,7 +34,7 @@ export * from './validators/fromJsonSchema.js';
  * - {@linkcode AjvJsonSchemaValidator}: Best for Node.js (default, fastest)
  *   Bundled — no additional dependencies required.
  *
- * - {@linkcode CfWorkerJsonSchemaValidator}: Best for edge runtimes
+ * - `CfWorkerJsonSchemaValidator`: Best for edge runtimes
  *   Import from: `@modelcontextprotocol/server/validators/cf-worker` or `@modelcontextprotocol/client/validators/cf-worker`
  *   Bundled — no additional dependencies required.
  *

packages/server/src/shimsWorkerd.ts

@@ -3,7 +3,7 @@
  *
  * This file is selected via package.json export conditions when running in workerd.
  */
-export { CfWorkerJsonSchemaValidator as DefaultJsonSchemaValidator } from '@modelcontextprotocol/core';
+export { CfWorkerJsonSchemaValidator as DefaultJsonSchemaValidator } from '@modelcontextprotocol/core/validators/cfWorker';
 
 /**
  * Stub process object for non-Node.js environments.

packages/server/src/validators/cfWorker.ts

@@ -6,5 +6,5 @@
  * import { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/server/validators/cf-worker';
  * ```
  */
-export { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/core';
-export type { CfWorkerSchemaDraft } from '@modelcontextprotocol/core';
+export type { CfWorkerSchemaDraft } from '@modelcontextprotocol/core/validators/cfWorker';
+export { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/core/validators/cfWorker';