The template uses TanStack Router with file-based routing. Each file in src/routes/ becomes a route automatically.

Layout routes use the _ prefix — they wrap child routes via <Outlet /> without adding a URL segment. For example, _sidebar.tsx provides the sidebar shell for all routes under _sidebar/.

The root layout (__root.tsx) provides the outermost wrapper.

Data fetching uses React Query (@tanstack/react-query). The QueryClient is created in main.tsx and passed through context.

API calls go through typed helpers in lib/api.ts:

const data = await get<MyType>("/endpoint")

In dev, requests to /api/* are intercepted by a Vite plugin and routed to the Hono server in-process — no CORS, no proxy, no separate server process.

Add a route handler in api.ts:

app.get("/api/my-endpoint", (c) => {
  return c.json({ message: "hello" })
})

That's it. The Vite plugin picks it up immediately in dev. In production, server.ts serves the Hono app directly.