diff --git a/auth-server/server.go b/auth-server/server.go
index 3959026..0a3557c 100644
--- a/auth-server/server.go
+++ b/auth-server/server.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/actor"
@@ -77,15 +78,61 @@ func (model StorageClientInfo) GetSecret() string {
 }
 
 func (model StorageClientInfo) GetDomain() string {
-	// implement as in-memory
+	return model.GetDomain()
 }
 
 func (model StorageClientInfo) IsPublic() bool {
-	// implement as in-memory
+	return model.IsPublic()
 }
 
 func (model StorageClientInfo) GetUserID() string {
-	// implement as in-memory
+	return model.GetUserID()
+}
+
+type InMemoryClient struct {
+	Id       string
+	Domain   string
+	IsPublic bool
+}
+
+var clients map[string]InMemoryClient
+
+func addInMemoryClient(id string, domain string, isPublic bool) error {
+	result := InMemoryClient{
+		Id:       id,
+		Domain:   domain,
+		IsPublic: isPublic,
+	}
+	_, contains := clients[id]
+	if contains {
+		return fmt.Errorf("client with id %s already exist", id)
+	} else {
+		clients[id] = result
+		return nil
+	}
+}
+
+func getInMemoryClient(id string) (*InMemoryClient, error) {
+	result, contains := clients[id]
+	if contains {
+		return &result, nil
+	} else {
+		return nil, fmt.Errorf("client with id %s not found", id)
+	}
+}
+
+func updateInMemoryClientById(id string, client InMemoryClient) error {
+	_, contains := clients[id]
+	if !contains || id != client.Id {
+		return fmt.Errorf("client with id %s not found", id)
+	} else {
+		clients[id] = client
+		return nil
+	}
+}
+
+func deleteInMemoryClient(id string) {
+	delete(clients, id)
 }
 
 func main() {
@@ -125,6 +172,13 @@ func main() {
 
 	http.HandleFunc("/login", func(w http.ResponseWriter, r *http.Request) {
 		srv.HandleTokenRequest(w, r)
+
+		id := r.Header.Get("client_id")
+		_, err := getInMemoryClient(id)
+		if err != nil {
+			slog.Warn("Client with id " + id + "not found")
+			w.WriteHeader(http.StatusBadRequest)
+		}
 	})
 
 	http.HandleFunc("/register", func(writer http.ResponseWriter, request *http.Request) {
@@ -151,6 +205,16 @@ func main() {
 			return
 		}
 
+		client, _ := clientStore.GetByID(context.Background(), id)
+		err = addInMemoryClient(
+			client.GetID(),
+			client.GetDomain(),
+			client.IsPublic())
+		if err != nil {
+			slog.Error(err.Error())
+			return
+		}
+
 		writer.WriteHeader(http.StatusOK)
 	})