Looking to fix my tRPC implementation

Hi guys I am looking for some help implementing tRPC in my current project, I have 3 files that need to be reviewed I think I almost have it but for some reason I am getting some errors. My goal is to replace the restful API endpoints and instead use tRPC.

My first file is: src/server/app.ts
Content:

import {
  addContextHandler,
  finalize,
  initialize,
  logger,
} from '@core-ui/service';
import * as dotenv from 'dotenv';
import express from 'express';
import { resolve } from 'path';
import 'reflect-metadata';
import { tRPCConfig } from './tRPC';

/* Refresh the token every 5 minutes */
dotenv.config();
export const app = express();

initialize({
  app,
});

addContextHandler(app);

app.use('/lib', express.static(resolve('dist/lib'), {}));

app.use('/trpc', tRPCConfig);
logger.info('Current env = ${process.env.NODE_ENV}');
finalize({ app });

Second file: src/server/tRPC/index.ts
Content:

import { inferAsyncReturnType, initTRPC } from '@trpc/server';
import * as trpcExpress from '@trpc/server/adapters/express';
import config from 'config';
import { z } from 'zod';

const createContext = ({
  req,
  res,
}: trpcExpress.CreateExpressContextOptions) => {
  return {
    req,
    res,
  };
};

type Context = inferAsyncReturnType<typeof createContext>;
const t = initTRPC.context<Context>().create();

const { router } = t;
const publicProcedure = t.procedure;

const alertsRouter = router({
  featureHealthAlerts: publicProcedure
    .input(
      z.object({
        serviceAlias: z.string().nullish(),
      }),
    )
    .query(async ({ input }) => {
      try {
        const serviceAlias = input.serviceAlias ?? 'kong';
        const baseURL: unknown = config.get(
          `coreUI.service.serviceProxies.${serviceAlias}.baseURL`,
        );
        const response: any = await fetch(`${baseURL}`);
        return response;
      } catch (error: any) {
        throw new Error(error?.message);
      }
    }),
});

const appRouter = router({
  alerts: alertsRouter,
});

export type AppRouter = typeof appRouter;

const tRPCConfig = trpcExpress.createExpressMiddleware({
  router: appRouter,
  createContext,
  onError({ error }) {
    console.error('Something went wrong', error);
  },
  batching: {
    enabled: true,
  },
});

export { tRPCConfig };

Third file: src/client/tRPC/index.ts
Content:

import { createTRPCProxyClient, httpBatchLink } from '@trpc/client';
import { AppRouter } from '../../server/tRPC';

const url = `/`;
const client = createTRPCProxyClient<AppRouter>({
  links: [
    httpBatchLink({
      url,
    }),
  ],
});

export { client };

Whats my goal? I would like to get results using this query for example:

import { client } from '../../tRPC';
const test = client.alerts.featureHealthAlerts.query({ serviceAlias: 'kong' });
test.then(data => {
  console.log('data => ', data);
});

This is my result:

You’ve added a prefix on the server but the errors don’t show the prefix

So you need the prefix on your client

Should be the same prefix @Nick Lucas ? or something different? Sorry I am new on this

It's just a HTTP URI

You wouldn't take out a rental agreement at 231 Spooner Street and then be surprised when all your stuff isn't in 234 Spooner Street. It's a different location

If you host tRPC at one URL, don't be surprised when a different URL returns a 404

Ok I have added this: src/client/tRPC/index.ts

import { createTRPCProxyClient, httpBatchLink } from '@trpc/client';
import { AppRouter } from '../../server/tRPC';

const url = `http://localhost:2021/trpc`;
const client = createTRPCProxyClient<AppRouter>({
  links: [
    httpBatchLink({
      url,
    }),
  ],
});

export { client };

Result:

What's the actual error code now?

And is the port you've set actually correct? I don't see that in your API setup

I am getting this:

My app uses 3000

What port is the API on though?

the updated code is port 2021, the error says 4000. Something's wrong 😄

Yeah I updated it one sec

My app works on this port: https://localhost.sparkcognition.com:3000/

I mean reactjs, so should I use this config:

import { createTRPCProxyClient, httpBatchLink } from '@trpc/client';
import { AppRouter } from '../../server/tRPC';

const url = 'https://localhost.sparkcognition.com:3000';

const client = createTRPCProxyClient<AppRouter>({
  links: [
    httpBatchLink({
      url,
    }),
  ],
});

export { client };

This is where I am not sure

Hi @nlucas sorry for bothering you, please let me know when you have a few mins to help me with this, thanks

This strikes me as needing to go back to basics a little. Setting a URL on both sides isn’t that hard, but throwing tRPC and next into the mix isn’t helping you

Why not follow an Express tutorial and just try to get a simple rest endpoint going and a simple react spa connect to it?

Then you can start swapping out parts and add tRPC to the express API

I am following this guide but I am still getting the error: https://codesandbox.io/s/github/trpc/trpc/tree/main/examples/express-server

@Nick Lucas I managed to fix it, thanks so much for the help! it was related with the address:
Server

app.use('/trpc', tRPCConfig);

Client

const client = createTRPCProxyClient<AppRouter>({
  links: [
    httpBatchLink({
      url: '/trpc',
    }),
  ],
});