diff --git a/internal/onie/onie.go b/internal/onie/onie.go
new file mode 100644
index 0000000..f46d38c
--- /dev/null
+++ b/internal/onie/onie.go
@@ -0,0 +1,13 @@
+// SPDX-FileCopyrightText: 2025 SAP SE or an SAP affiliate company and IronCore contributors
+// SPDX-License-Identifier: Apache-2.0
+
+package onie
+
+import "net/http"
+
+// Register a handler which serves the given directory over HTTP. See the ONIE
+// documentation for which file names are tried:
+// https://opencomputeproject.github.io/onie/design-spec/discovery.html
+func Register(mux *http.ServeMux, installerDir string) {
+	mux.Handle("GET /", http.FileServer(http.Dir(installerDir)))
+}
diff --git a/internal/ztp/ztp.go b/internal/ztp/ztp.go
index 1cf0fd8..92d02a0 100644
--- a/internal/ztp/ztp.go
+++ b/internal/ztp/ztp.go
@@ -64,12 +64,12 @@ type SwitchParameters struct {
 	ASNumber int          `json:"as_number"`
 }
 
-type Handler struct {
+type handler struct {
 	t *template.Template
 	m map[netip.Addr]SwitchParameters
 }
 
-func NewZTPHandler(c Config) *Handler {
+func Register(mux *http.ServeMux, c Config) {
 	t := template.New("ztp-scripts")
 	t = t.Funcs(template.FuncMap{
 		"add":             func(a, b int) int { return a + b },
@@ -79,10 +79,7 @@ func NewZTPHandler(c Config) *Handler {
 	})
 	t = template.Must(t.ParseFS(templateFS, "templates/*.gotmpl"))
 
-	return &Handler{
-		t: t,
-		m: c.SwitchParams,
-	}
+	mux.Handle("GET /ztp", &handler{t: t, m: c.SwitchParams})
 }
 
 // interfacePrefix takes the interface ID and the /64 prefix of the switch and
@@ -101,7 +98,7 @@ func interfacePrefix(prefix netip.Prefix, interfaceID int) (string, error) {
 	return prefix.String(), nil
 }
 
-func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	ap, err := netip.ParseAddrPort(r.RemoteAddr)
 	if err != nil {
 		handleErr(w, err)