Exceeds the Maximum Length Problem

TypeScript may report this error when you export a large or complex router. This is a known TypeScript limitation, not an oRPC bug. TypeScript enforces it to maintain reasonable editor and type-checking performance for large types.

export const router = {
The inferred type of this node exceeds the maximum length the compiler will serialize. An explicit type annotation is needed.
  // many procedures here
}

When It Happens

You usually see this error when all of the following are true:

1. Your project uses "declaration": true in tsconfig.json.
2. Your project is large or your types are very complex.
3. You export your router as a single, large object.

How to Fix It

1. Disable "declaration": true

If you don't need this feature, disable this option in your tsconfig.json:

tsconfig.json

  {
    "compilerOptions": {
--    "declaration": true,
++    "declaration": false
    }
  }

2. Add Explicit Output Types

Add .output or an explicit handler return type to your procedures. This lets TypeScript use the declared output shape instead of fully expanding the handler implementation, which often improves both type-checking and editor performance.

TIP

Use the type utility if you just want to specify the output type without validating the output.

3. Split the Router into Smaller Exports

If you need "declaration": true, avoid exporting a single massive router object from the server. Instead, export smaller router segments and combine them on the client side, where "declaration": false:

export const userRouter = { /** ... */ }
export const planetRouter = { /** ... */ }
export const publicRouter = { /** ... */ }

Then define the client type from those smaller exports:

interface Router {
  user: typeof userRouter
  planet: typeof planetRouter
  public: typeof publicRouter
}

export const client: RouterClient<Router> = createORPCClient(link)