sendou.ink/utils/trpc-server.ts

import * as trpc from "@trpc/server";
import * as trpcExpress from "@trpc/server/adapters/express/dist/trpc-server-adapters-express.cjs";

export const createContext = ({
  req,
  res,
}: trpcExpress.CreateExpressContextOptions) => {
  const getUser = () => {
    if (req.headers.authorization !== "secret") {
      return null;
    }
    return {
      name: "alex",
    };
  };

  return {
    req,
    res,
    user: getUser(),
  };
};
type Context = trpc.inferAsyncReturnType<typeof createContext>;

export function createRouter() {
  return trpc.router<Context>();
}