even more refactoring

proto/cart_actor.proto

@@ -3,66 +3,114 @@ syntax = "proto3";
 package messages;
 
 option go_package = "git.tornberg.me/go-cart-actor/proto;messages";
+
 import "messages.proto";
 
 // -----------------------------------------------------------------------------
-// Cart Actor gRPC API (oneof Envelope Variant)
+// Cart Actor gRPC API (Breaking v2 - Per-Mutation RPCs)
 // -----------------------------------------------------------------------------
-// This version removes the legacy numeric MutationType enum + raw bytes payload
-// approach and replaces it with a strongly typed oneof envelope. Each concrete
-// mutation proto is embedded directly, enabling:
-//   * Type-safe routing server-side (simple type switch on the oneof).
-//   * Direct persistence of MutationEnvelope messages (no custom binary header).
-//   * Elimination of the legacy message handler registry.
+// This version removes the previous MutationEnvelope + Mutate RPC.
+// Each mutation now has its own request wrapper and dedicated RPC method
+// providing simpler, type-focused client stubs and enabling per-mutation
+// metrics, auth and rate limiting.
 //
-// NOTE: Regenerate Go code after editing:
+// Regenerate Go code after editing:
 //   protoc --go_out=. --go_opt=paths=source_relative \
 //          --go-grpc_out=. --go-grpc_opt=paths=source_relative \
 //          proto/cart_actor.proto proto/messages.proto
+//
+// Backward compatibility: This is a breaking change (old clients must update).
 // -----------------------------------------------------------------------------
 
-// MutationEnvelope carries exactly one mutation plus metadata.
-// client_timestamp:
-//   - Optional Unix timestamp provided by the client.
-//   - If zero the server MAY overwrite with its local time.
-message MutationEnvelope {
-  string cart_id = 1;
-  int64 client_timestamp = 2;
-
-  oneof mutation {
-    AddRequest add_request = 10;
-    AddItem add_item = 11;
-    RemoveItem remove_item = 12;
-    RemoveDelivery remove_delivery = 13;
-    ChangeQuantity change_quantity = 14;
-    SetDelivery set_delivery = 15;
-    SetPickupPoint set_pickup_point = 16;
-    CreateCheckoutOrder create_checkout_order = 17;
-    SetCartRequest set_cart_items = 18;
-    OrderCreated order_completed = 19;
+// Shared reply for all mutation RPCs.
+message CartMutationReply {
+  int32 status_code = 1;          // HTTP-like status (200 success, 4xx client, 5xx server)
+  oneof result {
+    CartState state = 2;          // Updated cart state on success
+    string error = 3;             // Error message on failure
   }
+  int64 server_timestamp = 4;     // Server-assigned Unix timestamp (optional auditing)
 }
 
-// MutationReply returns a legacy-style status code plus a JSON payload
-// holding either the updated cart state (on success) or an error string.
-message MutationReply {
-  int32 status_code = 1;
+// Fetch current cart state without mutation.
+message StateRequest {
+  string cart_id = 1;
+}
 
-  // Exactly one of state or error will be set.
+message StateReply {
+  int32 status_code = 1;
   oneof result {
     CartState state = 2;
     string error = 3;
   }
 }
 
-// StateRequest fetches current cart state without mutating.
-message StateRequest {
+// Per-mutation request wrappers. We wrap the existing inner mutation
+// messages (defined in messages.proto) to add cart_id + optional metadata
+// without altering the inner message definitions.
+
+message AddRequestRequest {
   string cart_id = 1;
+  int64 client_timestamp = 2;
+  AddRequest payload = 10;
+}
+
+message AddItemRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  AddItem payload = 10;
+}
+
+message RemoveItemRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  RemoveItem payload = 10;
+}
+
+message RemoveDeliveryRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  RemoveDelivery payload = 10;
+}
+
+message ChangeQuantityRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  ChangeQuantity payload = 10;
+}
+
+message SetDeliveryRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  SetDelivery payload = 10;
+}
+
+message SetPickupPointRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  SetPickupPoint payload = 10;
+}
+
+message CreateCheckoutOrderRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  CreateCheckoutOrder payload = 10;
+}
+
+message SetCartItemsRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  SetCartRequest payload = 10;
+}
+
+message OrderCompletedRequest {
+  string cart_id = 1;
+  int64 client_timestamp = 2;
+  OrderCreated payload = 10;
 }
 
 // -----------------------------------------------------------------------------
-// CartState represents the full cart snapshot returned by state/mutation replies.
-// Replaces the previous raw JSON payload.
+// Cart state snapshot (unchanged from v1 except envelope removal context)
 // -----------------------------------------------------------------------------
 message CartState {
   string cart_id = 1;
@@ -76,7 +124,6 @@ message CartState {
   string payment_status = 9;
 }
 
-// Lightweight representation of an item in the cart
 message CartItemState {
   int64 id = 1;
   int64 source_item_id = 2;
@@ -105,38 +152,37 @@ message CartItemState {
   int32 stock = 25;
 }
 
-// Delivery / shipping entry
 message DeliveryState {
   int64 id = 1;
   string provider = 2;
   int64 price = 3;
   repeated int64 item_ids = 4;
-  PickupPoint pickup_point = 5;
+  PickupPoint pickup_point = 5; // Defined in messages.proto
 }
 
-// StateReply mirrors MutationReply for consistency.
-message StateReply {
-  int32 status_code = 1;
+// (CheckoutRequest / CheckoutReply removed - checkout handled at HTTP layer)
 
-  oneof result {
-    CartState state = 2;
-    string error = 3;
-  }
-}
-
-// CartActor exposes mutation and state retrieval for remote grains.
+// -----------------------------------------------------------------------------
+// Service definition (per-mutation RPCs + checkout)
+// -----------------------------------------------------------------------------
 service CartActor {
-  // Mutate applies a single mutation to a cart, creating the cart lazily if needed.
-  rpc Mutate(MutationEnvelope) returns (MutationReply);
+  rpc AddRequest(AddRequestRequest) returns (CartMutationReply);
+  rpc AddItem(AddItemRequest) returns (CartMutationReply);
+  rpc RemoveItem(RemoveItemRequest) returns (CartMutationReply);
+  rpc RemoveDelivery(RemoveDeliveryRequest) returns (CartMutationReply);
+  rpc ChangeQuantity(ChangeQuantityRequest) returns (CartMutationReply);
+  rpc SetDelivery(SetDeliveryRequest) returns (CartMutationReply);
+  rpc SetPickupPoint(SetPickupPointRequest) returns (CartMutationReply);
+  // (Checkout RPC removed - handled externally)
+  rpc SetCartItems(SetCartItemsRequest) returns (CartMutationReply);
+  rpc OrderCompleted(OrderCompletedRequest) returns (CartMutationReply);
 
-  // GetState retrieves the cart's current state (JSON).
   rpc GetState(StateRequest) returns (StateReply);
 }
 
 // -----------------------------------------------------------------------------
-// Future Enhancements:
-//   * Replace JSON state payload with a strongly typed CartState proto.
-//   * Add streaming RPC (e.g., WatchState) for live updates.
-//   * Add batch mutations (repeated MutationEnvelope) if performance requires.
-//   * Introduce optimistic concurrency via version fields if external writers appear.
+// Future enhancements:
+// * BatchMutate RPC (repeated heterogeneous mutations)
+// * Streaming state updates (WatchState)
+// * Versioning / optimistic concurrency control
 // -----------------------------------------------------------------------------

proto/cart_actor_grpc.pb.go

@@ -19,19 +19,36 @@ import (
 const _ = grpc.SupportPackageIsVersion9
 
 const (
-	CartActor_Mutate_FullMethodName   = "/messages.CartActor/Mutate"
-	CartActor_GetState_FullMethodName = "/messages.CartActor/GetState"
+	CartActor_AddRequest_FullMethodName     = "/messages.CartActor/AddRequest"
+	CartActor_AddItem_FullMethodName        = "/messages.CartActor/AddItem"
+	CartActor_RemoveItem_FullMethodName     = "/messages.CartActor/RemoveItem"
+	CartActor_RemoveDelivery_FullMethodName = "/messages.CartActor/RemoveDelivery"
+	CartActor_ChangeQuantity_FullMethodName = "/messages.CartActor/ChangeQuantity"
+	CartActor_SetDelivery_FullMethodName    = "/messages.CartActor/SetDelivery"
+	CartActor_SetPickupPoint_FullMethodName = "/messages.CartActor/SetPickupPoint"
+	CartActor_SetCartItems_FullMethodName   = "/messages.CartActor/SetCartItems"
+	CartActor_OrderCompleted_FullMethodName = "/messages.CartActor/OrderCompleted"
+	CartActor_GetState_FullMethodName       = "/messages.CartActor/GetState"
 )
 
 // CartActorClient is the client API for CartActor service.
 //
 // For semantics around ctx use and closing/ending streaming RPCs, please refer to https://pkg.go.dev/google.golang.org/grpc/?tab=doc#ClientConn.NewStream.
 //
-// CartActor exposes mutation and state retrieval for remote grains.
+// -----------------------------------------------------------------------------
+// Service definition (per-mutation RPCs + checkout)
+// -----------------------------------------------------------------------------
 type CartActorClient interface {
-	// Mutate applies a single mutation to a cart, creating the cart lazily if needed.
-	Mutate(ctx context.Context, in *MutationEnvelope, opts ...grpc.CallOption) (*MutationReply, error)
-	// GetState retrieves the cart's current state (JSON).
+	AddRequest(ctx context.Context, in *AddRequestRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	AddItem(ctx context.Context, in *AddItemRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	RemoveItem(ctx context.Context, in *RemoveItemRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	RemoveDelivery(ctx context.Context, in *RemoveDeliveryRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	ChangeQuantity(ctx context.Context, in *ChangeQuantityRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	SetDelivery(ctx context.Context, in *SetDeliveryRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	SetPickupPoint(ctx context.Context, in *SetPickupPointRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	// (Checkout RPC removed - handled externally)
+	SetCartItems(ctx context.Context, in *SetCartItemsRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
+	OrderCompleted(ctx context.Context, in *OrderCompletedRequest, opts ...grpc.CallOption) (*CartMutationReply, error)
 	GetState(ctx context.Context, in *StateRequest, opts ...grpc.CallOption) (*StateReply, error)
 }
 
@@ -43,10 +60,90 @@ func NewCartActorClient(cc grpc.ClientConnInterface) CartActorClient {
 	return &cartActorClient{cc}
 }
 
-func (c *cartActorClient) Mutate(ctx context.Context, in *MutationEnvelope, opts ...grpc.CallOption) (*MutationReply, error) {
+func (c *cartActorClient) AddRequest(ctx context.Context, in *AddRequestRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
 	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
-	out := new(MutationReply)
-	err := c.cc.Invoke(ctx, CartActor_Mutate_FullMethodName, in, out, cOpts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_AddRequest_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) AddItem(ctx context.Context, in *AddItemRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_AddItem_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) RemoveItem(ctx context.Context, in *RemoveItemRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_RemoveItem_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) RemoveDelivery(ctx context.Context, in *RemoveDeliveryRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_RemoveDelivery_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) ChangeQuantity(ctx context.Context, in *ChangeQuantityRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_ChangeQuantity_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) SetDelivery(ctx context.Context, in *SetDeliveryRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_SetDelivery_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) SetPickupPoint(ctx context.Context, in *SetPickupPointRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_SetPickupPoint_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) SetCartItems(ctx context.Context, in *SetCartItemsRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_SetCartItems_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *cartActorClient) OrderCompleted(ctx context.Context, in *OrderCompletedRequest, opts ...grpc.CallOption) (*CartMutationReply, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CartMutationReply)
+	err := c.cc.Invoke(ctx, CartActor_OrderCompleted_FullMethodName, in, out, cOpts...)
 	if err != nil {
 		return nil, err
 	}
@@ -67,11 +164,20 @@ func (c *cartActorClient) GetState(ctx context.Context, in *StateRequest, opts .
 // All implementations must embed UnimplementedCartActorServer
 // for forward compatibility.
 //
-// CartActor exposes mutation and state retrieval for remote grains.
+// -----------------------------------------------------------------------------
+// Service definition (per-mutation RPCs + checkout)
+// -----------------------------------------------------------------------------
 type CartActorServer interface {
-	// Mutate applies a single mutation to a cart, creating the cart lazily if needed.
-	Mutate(context.Context, *MutationEnvelope) (*MutationReply, error)
-	// GetState retrieves the cart's current state (JSON).
+	AddRequest(context.Context, *AddRequestRequest) (*CartMutationReply, error)
+	AddItem(context.Context, *AddItemRequest) (*CartMutationReply, error)
+	RemoveItem(context.Context, *RemoveItemRequest) (*CartMutationReply, error)
+	RemoveDelivery(context.Context, *RemoveDeliveryRequest) (*CartMutationReply, error)
+	ChangeQuantity(context.Context, *ChangeQuantityRequest) (*CartMutationReply, error)
+	SetDelivery(context.Context, *SetDeliveryRequest) (*CartMutationReply, error)
+	SetPickupPoint(context.Context, *SetPickupPointRequest) (*CartMutationReply, error)
+	// (Checkout RPC removed - handled externally)
+	SetCartItems(context.Context, *SetCartItemsRequest) (*CartMutationReply, error)
+	OrderCompleted(context.Context, *OrderCompletedRequest) (*CartMutationReply, error)
 	GetState(context.Context, *StateRequest) (*StateReply, error)
 	mustEmbedUnimplementedCartActorServer()
 }
@@ -83,8 +189,32 @@ type CartActorServer interface {
 // pointer dereference when methods are called.
 type UnimplementedCartActorServer struct{}
 
-func (UnimplementedCartActorServer) Mutate(context.Context, *MutationEnvelope) (*MutationReply, error) {
-	return nil, status.Errorf(codes.Unimplemented, "method Mutate not implemented")
+func (UnimplementedCartActorServer) AddRequest(context.Context, *AddRequestRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method AddRequest not implemented")
+}
+func (UnimplementedCartActorServer) AddItem(context.Context, *AddItemRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method AddItem not implemented")
+}
+func (UnimplementedCartActorServer) RemoveItem(context.Context, *RemoveItemRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method RemoveItem not implemented")
+}
+func (UnimplementedCartActorServer) RemoveDelivery(context.Context, *RemoveDeliveryRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method RemoveDelivery not implemented")
+}
+func (UnimplementedCartActorServer) ChangeQuantity(context.Context, *ChangeQuantityRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method ChangeQuantity not implemented")
+}
+func (UnimplementedCartActorServer) SetDelivery(context.Context, *SetDeliveryRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method SetDelivery not implemented")
+}
+func (UnimplementedCartActorServer) SetPickupPoint(context.Context, *SetPickupPointRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method SetPickupPoint not implemented")
+}
+func (UnimplementedCartActorServer) SetCartItems(context.Context, *SetCartItemsRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method SetCartItems not implemented")
+}
+func (UnimplementedCartActorServer) OrderCompleted(context.Context, *OrderCompletedRequest) (*CartMutationReply, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method OrderCompleted not implemented")
 }
 func (UnimplementedCartActorServer) GetState(context.Context, *StateRequest) (*StateReply, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method GetState not implemented")
@@ -110,20 +240,164 @@ func RegisterCartActorServer(s grpc.ServiceRegistrar, srv CartActorServer) {
 	s.RegisterService(&CartActor_ServiceDesc, srv)
 }
 
-func _CartActor_Mutate_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
-	in := new(MutationEnvelope)
+func _CartActor_AddRequest_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(AddRequestRequest)
 	if err := dec(in); err != nil {
 		return nil, err
 	}
 	if interceptor == nil {
-		return srv.(CartActorServer).Mutate(ctx, in)
+		return srv.(CartActorServer).AddRequest(ctx, in)
 	}
 	info := &grpc.UnaryServerInfo{
 		Server:     srv,
-		FullMethod: CartActor_Mutate_FullMethodName,
+		FullMethod: CartActor_AddRequest_FullMethodName,
 	}
 	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
-		return srv.(CartActorServer).Mutate(ctx, req.(*MutationEnvelope))
+		return srv.(CartActorServer).AddRequest(ctx, req.(*AddRequestRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_AddItem_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(AddItemRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).AddItem(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_AddItem_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).AddItem(ctx, req.(*AddItemRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_RemoveItem_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(RemoveItemRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).RemoveItem(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_RemoveItem_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).RemoveItem(ctx, req.(*RemoveItemRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_RemoveDelivery_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(RemoveDeliveryRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).RemoveDelivery(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_RemoveDelivery_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).RemoveDelivery(ctx, req.(*RemoveDeliveryRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_ChangeQuantity_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(ChangeQuantityRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).ChangeQuantity(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_ChangeQuantity_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).ChangeQuantity(ctx, req.(*ChangeQuantityRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_SetDelivery_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(SetDeliveryRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).SetDelivery(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_SetDelivery_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).SetDelivery(ctx, req.(*SetDeliveryRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_SetPickupPoint_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(SetPickupPointRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).SetPickupPoint(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_SetPickupPoint_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).SetPickupPoint(ctx, req.(*SetPickupPointRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_SetCartItems_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(SetCartItemsRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).SetCartItems(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_SetCartItems_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).SetCartItems(ctx, req.(*SetCartItemsRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _CartActor_OrderCompleted_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(OrderCompletedRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(CartActorServer).OrderCompleted(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: CartActor_OrderCompleted_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(CartActorServer).OrderCompleted(ctx, req.(*OrderCompletedRequest))
 	}
 	return interceptor(ctx, in, info, handler)
 }
@@ -154,8 +428,40 @@ var CartActor_ServiceDesc = grpc.ServiceDesc{
 	HandlerType: (*CartActorServer)(nil),
 	Methods: []grpc.MethodDesc{
 		{
-			MethodName: "Mutate",
-			Handler:    _CartActor_Mutate_Handler,
+			MethodName: "AddRequest",
+			Handler:    _CartActor_AddRequest_Handler,
+		},
+		{
+			MethodName: "AddItem",
+			Handler:    _CartActor_AddItem_Handler,
+		},
+		{
+			MethodName: "RemoveItem",
+			Handler:    _CartActor_RemoveItem_Handler,
+		},
+		{
+			MethodName: "RemoveDelivery",
+			Handler:    _CartActor_RemoveDelivery_Handler,
+		},
+		{
+			MethodName: "ChangeQuantity",
+			Handler:    _CartActor_ChangeQuantity_Handler,
+		},
+		{
+			MethodName: "SetDelivery",
+			Handler:    _CartActor_SetDelivery_Handler,
+		},
+		{
+			MethodName: "SetPickupPoint",
+			Handler:    _CartActor_SetPickupPoint_Handler,
+		},
+		{
+			MethodName: "SetCartItems",
+			Handler:    _CartActor_SetCartItems_Handler,
+		},
+		{
+			MethodName: "OrderCompleted",
+			Handler:    _CartActor_OrderCompleted_Handler,
 		},
 		{
 			MethodName: "GetState",

proto/messages.pb.go

@@ -889,6 +889,102 @@ func (x *OrderCreated) GetStatus() string {
 	return ""
 }
 
+type Noop struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *Noop) Reset() {
+	*x = Noop{}
+	mi := &file_messages_proto_msgTypes[11]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *Noop) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*Noop) ProtoMessage() {}
+
+func (x *Noop) ProtoReflect() protoreflect.Message {
+	mi := &file_messages_proto_msgTypes[11]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use Noop.ProtoReflect.Descriptor instead.
+func (*Noop) Descriptor() ([]byte, []int) {
+	return file_messages_proto_rawDescGZIP(), []int{11}
+}
+
+type InitializeCheckout struct {
+	state             protoimpl.MessageState `protogen:"open.v1"`
+	OrderId           string                 `protobuf:"bytes,1,opt,name=orderId,proto3" json:"orderId,omitempty"`
+	Status            string                 `protobuf:"bytes,2,opt,name=status,proto3" json:"status,omitempty"`
+	PaymentInProgress bool                   `protobuf:"varint,3,opt,name=paymentInProgress,proto3" json:"paymentInProgress,omitempty"`
+	unknownFields     protoimpl.UnknownFields
+	sizeCache         protoimpl.SizeCache
+}
+
+func (x *InitializeCheckout) Reset() {
+	*x = InitializeCheckout{}
+	mi := &file_messages_proto_msgTypes[12]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *InitializeCheckout) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*InitializeCheckout) ProtoMessage() {}
+
+func (x *InitializeCheckout) ProtoReflect() protoreflect.Message {
+	mi := &file_messages_proto_msgTypes[12]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use InitializeCheckout.ProtoReflect.Descriptor instead.
+func (*InitializeCheckout) Descriptor() ([]byte, []int) {
+	return file_messages_proto_rawDescGZIP(), []int{12}
+}
+
+func (x *InitializeCheckout) GetOrderId() string {
+	if x != nil {
+		return x.OrderId
+	}
+	return ""
+}
+
+func (x *InitializeCheckout) GetStatus() string {
+	if x != nil {
+		return x.Status
+	}
+	return ""
+}
+
+func (x *InitializeCheckout) GetPaymentInProgress() bool {
+	if x != nil {
+		return x.PaymentInProgress
+	}
+	return false
+}
+
 var File_messages_proto protoreflect.FileDescriptor
 
 const file_messages_proto_rawDesc = "" +
@@ -997,7 +1093,12 @@ const file_messages_proto_rawDesc = "" +
 	"\acountry\x18\x06 \x01(\tR\acountry\"@\n" +
 	"\fOrderCreated\x12\x18\n" +
 	"\aorderId\x18\x01 \x01(\tR\aorderId\x12\x16\n" +
-	"\x06status\x18\x02 \x01(\tR\x06statusB.Z,git.tornberg.me/go-cart-actor/proto;messagesb\x06proto3"
+	"\x06status\x18\x02 \x01(\tR\x06status\"\x06\n" +
+	"\x04Noop\"t\n" +
+	"\x12InitializeCheckout\x12\x18\n" +
+	"\aorderId\x18\x01 \x01(\tR\aorderId\x12\x16\n" +
+	"\x06status\x18\x02 \x01(\tR\x06status\x12,\n" +
+	"\x11paymentInProgress\x18\x03 \x01(\bR\x11paymentInProgressB.Z,git.tornberg.me/go-cart-actor/proto;messagesb\x06proto3"
 
 var (
 	file_messages_proto_rawDescOnce sync.Once
@@ -1011,7 +1112,7 @@ func file_messages_proto_rawDescGZIP() []byte {
 	return file_messages_proto_rawDescData
 }
 
-var file_messages_proto_msgTypes = make([]protoimpl.MessageInfo, 11)
+var file_messages_proto_msgTypes = make([]protoimpl.MessageInfo, 13)
 var file_messages_proto_goTypes = []any{
 	(*AddRequest)(nil),          // 0: messages.AddRequest
 	(*SetCartRequest)(nil),      // 1: messages.SetCartRequest
@@ -1024,6 +1125,8 @@ var file_messages_proto_goTypes = []any{
 	(*RemoveDelivery)(nil),      // 8: messages.RemoveDelivery
 	(*CreateCheckoutOrder)(nil), // 9: messages.CreateCheckoutOrder
 	(*OrderCreated)(nil),        // 10: messages.OrderCreated
+	(*Noop)(nil),                // 11: messages.Noop
+	(*InitializeCheckout)(nil),  // 12: messages.InitializeCheckout
 }
 var file_messages_proto_depIdxs = []int32{
 	0, // 0: messages.SetCartRequest.items:type_name -> messages.AddRequest
@@ -1051,7 +1154,7 @@ func file_messages_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_messages_proto_rawDesc), len(file_messages_proto_rawDesc)),
 			NumEnums:      0,
-			NumMessages:   11,
+			NumMessages:   13,
 			NumExtensions: 0,
 			NumServices:   0,
 		},

proto/messages.proto

@@ -93,3 +93,13 @@ message OrderCreated {
 		string orderId = 1;
 		string status = 2;
 }
+
+message Noop {
+		// Intentionally empty - used for ownership acquisition or health pings
+}
+
+message InitializeCheckout {
+        string orderId = 1;
+        string status = 2;
+        bool paymentInProgress = 3;
+}