TRPC pass res to ctx using app router

/**
 * This is the actual context you will use in your router. It will be used to process every request
 * that goes through your tRPC endpoint.
 *
 * @see https://trpc.io/docs/context
 */
export const createTRPCContext = async (opts: {
  req: NextRequest;
  // res: NextResponse;
}) => {
  // Fetch stuff that depends on the request

  const innerContext = await createInnerTRPCContext({
    headers: opts.req.headers,
  });

  return {
    ...innerContext,
    req: opts.req,
  };
};

import { fetchRequestHandler } from "@trpc/server/adapters/fetch";
import { type NextRequest } from "next/server";

import { env } from "~/env.mjs";
import { appRouter } from "~/server/api/root";
import { createTRPCContext } from "~/server/api/trpc";

const handler = (req: NextRequest) => {
  return fetchRequestHandler({
    endpoint: "/api/trpc",
    req,
    router: appRouter,
    createContext: () => createTRPCContext({ req }),
    onError:
      env.NODE_ENV === "development"
        ? ({ path, error }) => {
            console.error(
              `❌ tRPC failed on ${path ?? "<no-path>"}: ${error.message}`,
            );
          }
        : undefined,
  });
};

export { handler as GET, handler as POST };