Local-only request flow

The local flow never leaves your machine. It needs no server, token, or network; routeup setup alone enables it.

The path

browser
  -> https://api.example-app.localhost
  -> local agent (terminates TLS, looks up the route)
  -> 127.0.0.1:8080  (your service)
  -> response back through the agent

Step by step

1. Resolution. .localhost is reserved by RFC 6761, so browsers and resolvers short-circuit *.localhost to 127.0.0.1 with no DNS lookup and no /etc/hosts editing.
2. TLS. The request arrives at the local agent on port 443. The agent terminates TLS using a certificate signed by the routeup local CA, which setup added to your trust store, so the browser shows no warning.
3. Routing. The agent matches the request’s Host against its in-memory route registry to find the target port.
4. Proxy. It reverse-proxies to the local target (e.g. 127.0.0.1:8080) and streams the response back.

Because the registry is keyed by host, a dotted route like api.example-app works at any depth locally. The local CA mints a per-SNI leaf for the exact name.

See Local agent for the component, and Public exposure flow for what changes when a route is exposed.