Request Handler blowing up when using Node v24?

[JinxedStar]

Hello,

Our team has been using orpc and love it! We just started a new project and wanted to update all of our deps to the latest stuff so we don't fall behind :)

However, when we upgraded to node v24 we got weird errors and tracked it down to the RPCHandler not liking the new Request object or something?

TypeError: Cannot read private member #state from an object whose class did not declare it
    at handleRequest (src/app/(orpc)/api/orpc/[[...rest]]/route.ts:27:46)
  25 |  console.log("got orpc request", request);
  26 |
> 27 |  const { matched, response } = await handler.handle(request, {
     |                                              ^
  28 |          prefix: BASE_URL,
 POST /api/orpc/healthCheck 500 in 28ms (compile: 3ms, proxy.ts: 2ms, render: 23ms)

Is this a known problem or did we somehow mess up something in our configs/etc?

Thanks everyone!

[dosubot[bot]]

Hi @JinxedStar! I'm Dosu and I’m helping the orpc team.

This is a known issue with orpc and recent Node.js versions like v24. The error happens when there are multiple copies of a class with private fields (for example, from plugins like BodyLimitPlugin) loaded in your runtime—often due to module duplication in monorepos, Next.js, or when using Turbopack. JavaScript can't access private fields across different copies, so you get the "Cannot read private member #state" error.

To fix it: make sure you only have one copy of @orpc/server (and related packages) in your node_modules. Check for duplicate installs, symlinks, or local package links. If you're using Turbopack, try switching to Webpack or disabling Turbopack, as Turbopack is more likely to cause duplication. Updating all related dependencies (orpc, hono, etc.) and clearing caches has also resolved this for other users. If deduplication isn't possible, avoid plugins that use private fields or ask for a version that doesn't rely on them.

Recent orpc releases are tested with Node v24, but this error can still occur if deduplication isn't ensured. Let me know if you want step-by-step deduplication help or troubleshooting tips.

Reference: module duplication and private field error

To reply, just mention @dosu.

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[unnoq]

Can you help me create minimal repro without only Node.js + oRPC (without 3rd)?