ERR_MODULE_NOT_FOUND When Importing from proxyProvider Without .js Extension

[KD23243]

Describe the bug
Following the example in the README section on proxy authorization leads to a ERR_MODULE_NOT_FOUND error when importing from @modelcontextprotocol/sdk/server/auth/providers/proxyProvider.

To Reproduce
Steps to reproduce the behavior:

1. Follow the example import:

import { ProxyOAuthServerProvider, mcpAuthRouter } from '@modelcontextprotocol/sdk/server/auth/providers/proxyProvider';

2. Run the Node.js project (using ESM).

Expected behavior
The import should resolve correctly and not throw a ERR_MODULE_NOT_FOUND error.

Logs

node:internal/modules/esm/resolve:265
    throw new ERR_MODULE_NOT_FOUND(
          ^

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/Users/kumuditha/Documents/mcpHackerthon/my/untitled folder/node_modules/@modelcontextprotocol/sdk/dist/esm/server/auth/providers/proxyProvider' imported from /Users/kumuditha/Documents/mcpHackerthon/my/untitled folder/client.js
    at finalizeResolution (node:internal/modules/esm/resolve:265:11)
    at moduleResolve (node:internal/modules/esm/resolve:933:10)
    at defaultResolve (node:internal/modules/esm/resolve:1169:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:383:12)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:352:25)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:227:38)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:87:39)
    at link (node:internal/modules/esm/module_job:86:36) {
  code: 'ERR_MODULE_NOT_FOUND',
  url: 'file:///Users/kumuditha/Documents/mcpHackerthon/my/untitled%20folder/node_modules/@modelcontextprotocol/sdk/dist/esm/server/auth/providers/proxyProvider'
}

Additional context
Modifying the import to include the .js extension resolved the issue:

import { mcpAuthRouter } from '@modelcontextprotocol/sdk/server/auth/router.js';
import { ProxyOAuthServerProvider } from '@modelcontextprotocol/sdk/server/auth/providers/proxyProvider.js';

This may require either fixing the documentation example or updating the SDK’s exports field in package.json to support extensionless ESM imports.