diff --git a/client/api/controller.go b/client/api/controller.go
new file mode 100644
index 00000000..e39e3fc4
--- /dev/null
+++ b/client/api/controller.go
@@ -0,0 +1,18 @@
+package api
+
+type Controller interface {
+	CreateDerivedSpace() (id string, err error)
+	CreateSpace() (id string, err error)
+	GetAllSpacesIds() (ids []string, err error)
+	// LoadSpace asks node to load a particular space
+	LoadSpace(id string) (err error)
+
+	CreateDocument(spaceId string) (id string, err error)
+	GetAllDocumentIds(spaceId string) (ids []string, err error)
+	AddText(documentId, text string) (err error)
+	DumpDocumentTree(documentId string) (err error)
+
+	GetValidInvites(spaceId string) (invites []string, err error)
+	GenerateInvite(spaceId string) (invite string, err error)
+	JoinSpace(invite string) (err error)
+}
diff --git a/common/commonspace/service.go b/common/commonspace/service.go
index dd0347a1..c7c27081 100644
--- a/common/commonspace/service.go
+++ b/common/commonspace/service.go
@@ -22,8 +22,8 @@ func New() Service {
 }
 
 type Service interface {
-	CreateSpace(ctx context.Context, cache cache.TreeCache, payload SpaceCreatePayload) (Space, error)
-	DeriveSpace(ctx context.Context, cache cache.TreeCache, payload SpaceDerivePayload) (Space, error)
+	DeriveSpace(ctx context.Context, payload SpaceDerivePayload) (Space, error)
+	CreateSpace(ctx context.Context, payload SpaceCreatePayload) (Space, error)
 	GetSpace(ctx context.Context, id string) (sp Space, err error)
 	app.Component
 }
@@ -51,7 +51,6 @@ func (s *service) Name() (name string) {
 
 func (s *service) CreateSpace(
 	ctx context.Context,
-	cache cache.TreeCache,
 	payload SpaceCreatePayload) (sp Space, err error) {
 	storageCreate, err := storagePayloadForSpaceCreate(payload)
 	if err != nil {
@@ -67,7 +66,6 @@ func (s *service) CreateSpace(
 
 func (s *service) DeriveSpace(
 	ctx context.Context,
-	cache cache.TreeCache,
 	payload SpaceDerivePayload) (sp Space, err error) {
 	storageCreate, err := storagePayloadForSpaceDerive(payload)
 	if err != nil {