@workos-inc/node is being loaded in browser causing "pluralize module not found" error with Convex integration

[sc30gsw]

Describe the bug

When using @workos/authkit-tanstack-react-start with Convex integration, the Node.js-only dependency @workos-inc/node is being loaded in the browser, causing a module resolution error for pluralize.

The error completely blocks JavaScript execution, preventing the application from functioning.

Error Messages

GET http://localhost:3000/node_modules/@workos-inc/node/lib/esm/common/exceptions/unprocessable-entity.exception.js 
net::ERR_ABORTED 500 (Internal Server Error)

Uncaught (in promise) SyntaxError: The requested module '/node_modules/pluralize/pluralize.js' does not provide an export named 'default' 
(at unprocessable-entity.exception.js:3:8)

Uncaught (in promise) TypeError: Failed to fetch dynamically imported module: http://localhost:3000/@id/virtual:tanstack-start-client-entry

The problematic code from @workos-inc/node:

import pluralize from "/node_modules/pluralize/pluralize.js";

class UnprocessableEntityException extends Error {
    // ... rest of the code
}

To Reproduce

Setup:

1. Create a new TanStack Start project with Convex integration
2. Install @workos/authkit-tanstack-react-start@0.2.0
3. Configure WorkOS AuthKit following the official documentation
4. Add AuthKitProvider with ConvexProviderWithAuth

File structure:

src/router.tsx:

import { AuthKitProvider } from '@workos/authkit-tanstack-react-start/client';
import { ConvexProviderWithAuth } from 'convex/react';

export function getRouter() {
  const router = createRouter({
    routeTree,
    context: { queryClient, convexClient: convex, convexQueryClient },
    Wrap: ({ children }) => (
      <AuthKitProvider>
        <ConvexProviderWithAuth client={convexQueryClient.convexClient} useAuth={useAuthFromWorkOS}>
          {children}
        </ConvexProviderWithAuth>
      </AuthKitProvider>
    ),
  });
  return router;
}

vite.config.ts:

import { defineConfig } from 'vite';
import tsConfigPaths from 'vite-tsconfig-paths';
import { tanstackStart } from '@tanstack/react-start/plugin/vite';
import viteReact from '@vitejs/plugin-react';

export default defineConfig({
  server: { port: 3000 },
  plugins: [tsConfigPaths(), tanstackStart(), viteReact()],
});

Steps:

1. Run npm run dev
2. Navigate to http://localhost:3000
3. Check browser console - pluralize error blocks all JavaScript

Expected behavior

• @workos-inc/node should never be loaded in the browser
• The library should properly separate client-side and server-side code
• AuthKitProvider and useAuth() should work correctly with Convex integration

Actual behavior

• @workos-inc/node is loaded in the browser
• pluralize module error blocks JavaScript execution
• Application completely non-functional

Environment

{
  "@workos/authkit-tanstack-react-start": "0.2.0",
  "@tanstack/react-router": "^1.132.41",
  "@tanstack/react-start": "^1.132.43",
  "convex": "^1.28.0",
  "@convex-dev/react-query": "^0.0.0-alpha.11",
  "vite": "^7.1.8"
}

Dependency tree:

@workos/authkit-tanstack-react-start@0.2.0
  └─┬ @workos/authkit-session@0.1.2
    └── @workos-inc/node@8.0.0-rc.2
      └── pluralize@8.0.0

Node.js: v20.x
Browser: Chrome/Safari (latest)
OS: macOS

Observations

1. Official example works fine (without Convex integration)
2. Server-side authentication works - getAuth() in loaders successfully returns user data
3. Only client-side fails - useAuth() hook causes the browser error
4. No Vite SSR configuration helps - Tried various ssr.external, optimizeDeps.exclude settings with no success

Attempted Solutions

1. ✗ Added @workos-inc/node to ssr.external in vite.config.ts
2. ✗ Added pluralize to optimizeDeps.exclude
3. ✗ Tried aliasing pluralize to empty module
4. ✗ Cleared all caches and reinstalled dependencies

None of these resolved the issue.

Possible Root Cause

The @workos/authkit-tanstack-react-start/client export may not be properly isolating client-side code from server-side dependencies. The @workos-inc/node package should only be imported on the server, but appears to be bundled for the client.

Workaround Needed

Is there a recommended way to use WorkOS AuthKit with Convex in TanStack Start that avoids this issue?

[dangnhdev]

I'm having this issue too. I'm not using Convex, just default tanstack start + MUI setup.

[dangnhdev]

Maybe this is caused by TanStack/router#5738

[sc30gsw]

@dangnhdev
Thank you for your information about the cause.
I hope the responsible team will be able to resolve this issue soon.

[dangnhdev]

I've locked tanstack start version to 1.134.6 and this package (workos integration) worked well. I think we can continue...start 😄

"@tanstack/react-start": "1.134.6"

[sc30gsw]

@dangnhdev
Thanks.
I'll try the way you showed me!

[foresttoney]

I just tried to integrate with a new installation of start and am seeing something very similar except (workos-node being called from the browser). I tried to pin to the suggested version and am still seeing the issue.