diff --git a/node.go b/node.go
index e3df35b..a4b1bea 100644
--- a/node.go
+++ b/node.go
@@ -508,7 +508,7 @@ func (node *Node) Process(ctx *Context, source NodeID, signal Signal) error {
   return ctx.Send(messages)
 }
 
-func GetCtx[T Extension, C any](ctx *Context, ext_type ExtType) (C, error) {
+func GetCtx[C any](ctx *Context, ext_type ExtType) (C, error) {
   var zero_ctx C
   ext_info, ok := ctx.Extensions[ext_type]
   if ok == false {
diff --git a/signal.go b/signal.go
index 1aa6468..cd4570d 100644
--- a/signal.go
+++ b/signal.go
@@ -20,8 +20,12 @@ type SignalHeader struct {
   ReqID uuid.UUID `gv:"req_id"`
 }
 
+func (header SignalHeader) Header() SignalHeader {
+  return header
+}
+
 type Signal interface {
-  Header() *SignalHeader
+  Header() SignalHeader
   Permission() Tree
 }
 
@@ -95,9 +99,6 @@ type CreateSignal struct {
   SignalHeader
 }
 
-func (signal CreateSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 func (signal CreateSignal) Permission() Tree {
   return Tree{
     SerializedType(CreateSignalType): nil,
@@ -113,9 +114,6 @@ func NewCreateSignal() *CreateSignal {
 type StartSignal struct {
   SignalHeader
 }
-func (signal StartSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 func (signal StartSignal) Permission() Tree {
   return Tree{
     SerializedType(StartSignalType): nil,
@@ -130,9 +128,6 @@ func NewStartSignal() *StartSignal {
 type StopSignal struct {
   SignalHeader
 }
-func (signal StopSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 func (signal StopSignal) Permission() Tree {
   return Tree{
     SerializedType(StopSignalType): nil,
@@ -148,9 +143,6 @@ type ErrorSignal struct {
   SignalHeader
   Error string
 }
-func (signal ErrorSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 func (signal ErrorSignal) Permission() Tree {
   return Tree{
     SerializedType(ErrorSignalType): nil,
@@ -166,9 +158,6 @@ func NewErrorSignal(req_id uuid.UUID, fmt_string string, args ...interface{}) Si
 type ACLTimeoutSignal struct {
   SignalHeader
 }
-func (signal ACLTimeoutSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 func (signal ACLTimeoutSignal) Permission() Tree {
   return Tree{
     SerializedType(ACLTimeoutSignalType): nil,
@@ -186,9 +175,6 @@ type StatusSignal struct {
   Source NodeID `gv:"source"`
   Status string `gv:"status"`
 }
-func (signal StatusSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 func (signal StatusSignal) Permission() Tree {
   return Tree{
     SerializedType(StatusSignalType): nil,
@@ -207,9 +193,6 @@ type LinkSignal struct {
   NodeID
   Action string
 }
-func (signal LinkSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 
 const (
   LinkActionBase = "LINK_ACTION"
@@ -235,9 +218,6 @@ type LockSignal struct {
   SignalHeader
   State string
 }
-func (signal LockSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 
 const (
   LockStateBase = "LOCK_STATE"
@@ -262,9 +242,6 @@ type ReadSignal struct {
   SignalHeader
   Extensions map[ExtType][]string `json:"extensions"`
 }
-func (signal ReadSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 
 func (signal ReadSignal) Permission() Tree {
   ret := Tree{}
@@ -290,9 +267,6 @@ type ReadResultSignal struct {
   NodeType NodeType
   Extensions map[ExtType]map[string]SerializedValue
 }
-func (signal ReadResultSignal) Header() *SignalHeader {
-  return &signal.SignalHeader
-}
 func (signal ReadResultSignal) Permission() Tree {
   return Tree{
     SerializedType(ReadResultSignalType): nil,