devserver

type Options struct {
	Dir      string        // project root (with go.mod)
	Addr     string        // proxy address, e.g. ":8080"
	Args     []string      // app arguments; default "run"
	Poll     time.Duration // how often to look for changes; default 300ms
	Out      io.Writer     // progress and the app's output
	OnListen func(addr string)
	// Hosts are the host names (without port) browsers may use besides
	// localhost, *.localhost and IP addresses, such as APP_URL's
	// ("blog.test"). Others get 403: a page on another site can't reach
	// the dev server by pointing its own name at 127.0.0.1 (DNS
	// rebinding).
	Hosts []string
}