types: createServerFn does not accept branded strings

[ben-pr-p]

Which project does this relate to?

Start

Describe the bug

Code:

export const listWidgets = createServerFn({ method: "GET" }).handler(
  async () => {
    return [
      {
        id: "1" as string & {
          __brand: "id";
        },
        name: "Widget 1",
      },
    ];
  }
);

Type error:

 Type '() => string' is not assignable to type '"Function is not serializable"'

Is the type error.

Steps to Reproduce the Bug or Issue

Code above.

Expected behavior

It should allow branded strings - commonly used for database IDs, etc.

Screenshots or Videos

No response

Platform

    "@tanstack/react-router": "^1.95.5",
    "@tanstack/start": "^1.95.5",

Additional context

No response