diff --git a/main.go b/main.go
index f6e5ffe..41ca94d 100644
--- a/main.go
+++ b/main.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"strings"
 
 	"github.com/gorilla/mux"
 	"github.com/nrednav/cuid2"
@@ -28,6 +29,7 @@ func main() {
 	users = make(map[string]string)
 
 	router.HandleFunc("/register", Register)
+	router.HandleFunc("/validate", ValidateId)
 
 	port, ok := os.LookupEnv("PORT")
 	if !ok {
@@ -92,5 +94,22 @@ func Register(writer http.ResponseWriter, request *http.Request) {
 }
 
 func ValidateId(writer http.ResponseWriter, request *http.Request) {
+	// (try to) get the Bearer token
+	reqToken := request.Header.Get("Authorization")
+	if !strings.HasPrefix(reqToken, "Bearer ") {
+		// return 401
+		writer.WriteHeader(http.StatusUnauthorized)
+	}
 
+	bearerToken := reqToken[7:]
+
+	// Check that the token is in the global map
+	_, ok := users[bearerToken]
+	if !ok {
+		// Return 401
+		writer.WriteHeader(http.StatusUnauthorized)
+	}
+
+	// Return Ok
+	writer.WriteHeader(http.StatusOK)
 }