Request boundary

Files under an api/ directory of the routes dir are API routes; they are served by the same generated entry as pages and are never prerendered. Requests and responses are the Web Request and Response objects.

Handler shape

An API route default-exports either a Hono app (mounted with app.route()) or a function (ctx) => Response receiving { request, params, env, platform } (mounted with app.all()). Keep input parsing, validation, and response serialization visible in the route.

app/routes/api/hello.ts

// Files under an api/ directory are API routes. Default-export a Hono
// app (mounted with app.route()) or a function (ctx) => Response
// (mounted with app.all()).
export default function hello(ctx: {
  request: Request;
  params: Record<string, string>;
  env: Record<string, string | undefined>;
  platform?: unknown;
}) {
  const url = new URL(ctx.request.url);
  return Response.json({ hello: url.searchParams.get('name') ?? 'world' });
}

The same default-export contract applies at every depth: app/routes/api/items/[id].ts serves /api/items/:id with params populated from the path.

Runtime fit

Use Deno-first tasks and avoid Node-only assumptions in docs examples.