diff --git a/smalltrip/multiplexer/multiplexer.go b/smalltrip/multiplexer/multiplexer.go
new file mode 100644
index 0000000..8ba09fe
--- /dev/null
+++ b/smalltrip/multiplexer/multiplexer.go
@@ -0,0 +1,25 @@
+// Copyright 2025-present Gustavo "Guz" L. de Mello
+// Copyright 2025-present The Lored.dev Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package multiplexer
+
+import "net/http"
+
+type Multiplexer interface {
+	HandleFunc(pattern string, handler func(http.ResponseWriter, *http.Request))
+	Handle(pattern string, handler http.Handler)
+	Handler(r *http.Request) (h http.Handler, pattern string)
+	http.Handler
+}
diff --git a/smalltrip/options.go b/smalltrip/options.go
index 5c573ce..0907ebd 100644
--- a/smalltrip/options.go
+++ b/smalltrip/options.go
@@ -19,6 +19,7 @@ import (
 	"log/slog"
 
 	"forge.capytal.company/loreddev/x/smalltrip/middleware"
+	"forge.capytal.company/loreddev/x/smalltrip/multiplexer"
 )
 
 type Option func(*router)
@@ -29,7 +30,9 @@ func WithLogger(logger *slog.Logger) Option {
 	}
 }
 
+func WithMultiplexer(mux multiplexer.Multiplexer) Option {
 	return func(r *router) {
+		r.mux = mux
 	}
 }
 
diff --git a/smalltrip/smalltrip.go b/smalltrip/smalltrip.go
index b8940c4..d5ddcd4 100644
--- a/smalltrip/smalltrip.go
+++ b/smalltrip/smalltrip.go
@@ -16,27 +16,22 @@
 package smalltrip
 
 import (
+	"fmt"
 	"io"
 	"log/slog"
 	"net/http"
-	"path"
-	"strings"
 
 	"forge.capytal.company/loreddev/x/smalltrip/middleware"
-	"forge.capytal.company/loreddev/x/tinyssert"
+	"forge.capytal.company/loreddev/x/smalltrip/multiplexer"
 )
 
 type Router interface {
-	Handle(pattern string, handler http.Handler)
-	HandleFunc(pattern string, handler func(http.ResponseWriter, *http.Request))
-
-	Use(middleware middleware.Middleware)
-
-	http.Handler
+	multiplexer.Multiplexer
+	Use(middleware.Middleware)
 }
 
 type router struct {
-	mux         *http.ServeMux
+	mux multiplexer.Multiplexer
 	mws []middleware.Middleware
 	log *slog.Logger
 }