What is the best way to use RPC for type safety in more complex app structures?

[banjo]

Hi,

All the examples for RPC only shows one route as an example. What is the best way to implement this with multiple routes? Or even, multiple app instances used as routes?

Like this:

const app = new Hono();

app.route("/feed", feed);
app.route("/item", item);
app.route("/items", items);

// where each app has several routes
const feed = new Hono();
feed.get(//...)
feed.post(//...)

The documentation doesn't really mention anything about this. Do we need to handle the type for each route and export them manually or what is the best way?

[yusukebe]

Indeed, I believe that separating "apps" and then combining them using app.route() is the optimal approach. And, if you want to use "RPC", try the following structure:

const feed = new Hono();
const feedRoutes = feed.get('/foo', (c) => c.jsonT(0)).post('/bar', (c) => c.jsonT('a'));

const item = new Hono();
const itemRoutes = item.get('/foo', (c) => c.jsonT(0)).post('/bar', (c) => c.jsonT('a'));

const mainApp = new Hono();

const allRoutes = mainApp.route('/feed', feedRoutes).route('/item', itemRoutes);

For more insights, @subhendupsingh has written a fantastic guide on the topic. Check it out!:
https://dev.to/subhendupsingh/typed-fetch-with-sveltekit-and-hono-using-rpc-2clf

[banjo]

Amazing, thank you very much.

[alpharder]

Just use tRPC instead.

[yusukebe]

You are right and we have a tRPC adapter, but we don't talk about it now.