I’m trying to use my regular express api/* routes with remix following the steps in this Discussion. It works like a charm in dev mode, but in production env routes are not found (404). I create the build using remix vite:build.

The dependencies relevant to this question:

    "@remix-run/dev": "^2.10.3",
    "@remix-run/serve": "^2.10.3",
    
    "@remix-run/express": "^2.10.3",
    "@remix-run/node": "^2.10.3",
    "@remix-run/react": "^2.10.3",

Below is a snippet from server.ts:

const viteDevServer =
  process.env.NODE_ENV === "production"
    ? undefined
    : await import("vite").then(vite =>
        vite.createServer({
          server: { middlewareMode: true }
        })
      );
      
 const remixHandler = createRequestHandler({
  build: viteDevServer
    ? () =>
        viteDevServer.ssrLoadModule(
          "virtual:remix/server-build"
        ) as Promise<ServerBuild>
    : await import("./build/server/index.js")
});
 
app.use(
  "/api",
  viteDevServer
    ? (req, res, next) =>
        viteDevServer
          .ssrLoadModule("virtual:remix/server-build")
          .then(m => m.entry.module.api(req, res, next))
          .catch(err => next(err))
    : (await import("./build/server/index.js")).entry.module.api
);


// handle SSR requests
app.all("*", remixHandler);

const PORT = process.env.PORT || 5000;

app.listen(PORT, () =>
  console.log(`Express server listening at http://localhost:${PORT}`)
);

After looking at the production build, I discovered that the build/server/index.js contains the router defined but doesn’t include the app.use("/api") statement.