diff --git a/Taskfile.yml b/Taskfile.yml
index 35c077f..01f1fe1 100644
--- a/Taskfile.yml
+++ b/Taskfile.yml
@@ -18,7 +18,7 @@ vars:
   PROTOC_GEN_GO: '{{.BIN_DIR}}/protoc-gen-go'
   PROTOC_GEN_GO_GRPC: '{{.BIN_DIR}}/protoc-gen-go-grpc'
 
-  MODULES: inventory order payment shared
+  MODULES: inventory payment shared
 
 tasks:
   install-formatters:
diff --git a/order/main.go b/order/main.go
deleted file mode 100644
index 567b486..0000000
--- a/order/main.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package main
-
-import "log"
-
-func main() {
-	log.Println("order up")
-}
diff --git a/payment/cmd/main.go b/payment/cmd/main.go
new file mode 100644
index 0000000..fa37243
--- /dev/null
+++ b/payment/cmd/main.go
@@ -0,0 +1,82 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/google/uuid"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/reflection"
+	"google.golang.org/grpc/status"
+
+	paymentv1 "github.com/qyrlabs/test-backend/shared/pkg/proto/payment/v1"
+)
+
+const grpcPort = 50062
+
+type paymentService struct {
+	paymentv1.UnimplementedPaymentServiceServer
+}
+
+// Initiates order payment.
+func (s *paymentService) PayOrder(ctx context.Context, req *paymentv1.PayOrderRequest) (*paymentv1.PayOrderResponse, error) {
+	if _, err := uuid.Parse(req.GetOrderUuid()); err != nil {
+		return nil, status.Errorf(codes.InvalidArgument, "invalid order_uuid format: %v", err)
+	}
+	if _, err := uuid.Parse(req.GetUserUuid()); err != nil {
+		return nil, status.Errorf(codes.InvalidArgument, "invalid user_uuid format: %v", err)
+	}
+	if req.GetPaymentMethod() == 0 {
+		return nil, status.Error(codes.InvalidArgument, "invalid payment method")
+	}
+
+	uuid := uuid.New().String()
+	log.Printf("Payment succeed, transaction_uuid: %s", uuid)
+	return &paymentv1.PayOrderResponse{
+		TransactionUuid: uuid,
+	}, nil
+}
+
+func main() {
+	lis, err := net.Listen("tcp", fmt.Sprintf("localhost:%d", grpcPort))
+	if err != nil {
+		log.Printf("failed to listen: %v\n", err)
+		return
+	}
+
+	defer func() {
+		if cerr := lis.Close(); cerr != nil {
+			log.Printf("failed to close listener: %v\n", cerr)
+		}
+	}()
+
+	grpcServer := grpc.NewServer()
+	reflection.Register(grpcServer)
+
+	service := &paymentService{}
+
+	paymentv1.RegisterPaymentServiceServer(grpcServer, service)
+
+	go func() {
+		log.Printf("gRPC server listening on %s\n", lis.Addr().String())
+		err := grpcServer.Serve(lis)
+		if err != nil {
+			log.Printf("Failed to serve: %v\n", err)
+			return
+		}
+	}()
+
+	// Graceful shutdown
+	quit := make(chan os.Signal, 1)
+	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+	<-quit
+	log.Println("Shutting down gRPC server...")
+	grpcServer.GracefulStop()
+	log.Println("gRPC server stopped")
+}
diff --git a/payment/go.mod b/payment/go.mod
index b352d61..8253de3 100644
--- a/payment/go.mod
+++ b/payment/go.mod
@@ -1,3 +1,19 @@
 module github.com/qyrlabs/test-backend/payment
 
 go 1.25.6
+
+replace github.com/qyrlabs/test-backend/shared => ../shared
+
+require (
+	github.com/google/uuid v1.6.0
+	github.com/qyrlabs/test-backend/shared v0.0.0-00010101000000-000000000000
+	google.golang.org/grpc v1.78.0
+)
+
+require (
+	golang.org/x/net v0.47.0 // indirect
+	golang.org/x/sys v0.38.0 // indirect
+	golang.org/x/text v0.31.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260120174246-409b4a993575 // indirect
+	google.golang.org/protobuf v1.36.11 // indirect
+)
diff --git a/payment/go.sum b/payment/go.sum
new file mode 100644
index 0000000..ae87d8a
--- /dev/null
+++ b/payment/go.sum
@@ -0,0 +1,36 @@
+github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
+github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
+github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
+go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
+go.opentelemetry.io/otel v1.38.0 h1:RkfdswUDRimDg0m2Az18RKOsnI8UDzppJAtj01/Ymk8=
+go.opentelemetry.io/otel v1.38.0/go.mod h1:zcmtmQ1+YmQM9wrNsTGV/q/uyusom3P8RxwExxkZhjM=
+go.opentelemetry.io/otel/metric v1.38.0 h1:Kl6lzIYGAh5M159u9NgiRkmoMKjvbsKtYRwgfrA6WpA=
+go.opentelemetry.io/otel/metric v1.38.0/go.mod h1:kB5n/QoRM8YwmUahxvI3bO34eVtQf2i4utNVLr9gEmI=
+go.opentelemetry.io/otel/sdk v1.38.0 h1:l48sr5YbNf2hpCUj/FoGhW9yDkl+Ma+LrVl8qaM5b+E=
+go.opentelemetry.io/otel/sdk v1.38.0/go.mod h1:ghmNdGlVemJI3+ZB5iDEuk4bWA3GkTpW+DOoZMYBVVg=
+go.opentelemetry.io/otel/sdk/metric v1.38.0 h1:aSH66iL0aZqo//xXzQLYozmWrXxyFkBJ6qT5wthqPoM=
+go.opentelemetry.io/otel/sdk/metric v1.38.0/go.mod h1:dg9PBnW9XdQ1Hd6ZnRz689CbtrUp0wMMs9iPcgT9EZA=
+go.opentelemetry.io/otel/trace v1.38.0 h1:Fxk5bKrDZJUH+AMyyIXGcFAPah0oRcT+LuNtJrmcNLE=
+go.opentelemetry.io/otel/trace v1.38.0/go.mod h1:j1P9ivuFsTceSWe1oY+EeW3sc+Pp42sO++GHkg4wwhs=
+golang.org/x/net v0.47.0 h1:Mx+4dIFzqraBXUugkia1OOvlD6LemFo1ALMHjrXDOhY=
+golang.org/x/net v0.47.0/go.mod h1:/jNxtkgq5yWUGYkaZGqo27cfGZ1c5Nen03aYrrKpVRU=
+golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
+golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.31.0 h1:aC8ghyu4JhP8VojJ2lEHBnochRno1sgL6nEi9WGFGMM=
+golang.org/x/text v0.31.0/go.mod h1:tKRAlv61yKIjGGHX/4tP1LTbc13YSec1pxVEWXzfoeM=
+gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
+gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260120174246-409b4a993575 h1:vzOYHDZEHIsPYYnaSYo60AqHkJronSu0rzTz/s4quL0=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260120174246-409b4a993575/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
+google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
+google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
diff --git a/payment/main.go b/payment/main.go
deleted file mode 100644
index 2fe1a5f..0000000
--- a/payment/main.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package main
-
-import "log"
-
-func main() {
-	log.Println("payment up")
-}
diff --git a/shared/main.go b/shared/main.go
deleted file mode 100644
index 55470b6..0000000
--- a/shared/main.go
+++ /dev/null
@@ -1,9 +0,0 @@
-package main
-
-import (
-	"log"
-)
-
-func main() {
-	log.Println("shared up")
-}
diff --git a/shared/pkg/proto/payment/v1/payment.pb.go b/shared/pkg/proto/payment/v1/payment.pb.go
new file mode 100644
index 0000000..31ce8b3
--- /dev/null
+++ b/shared/pkg/proto/payment/v1/payment.pb.go
@@ -0,0 +1,270 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.36.11
+// 	protoc        (unknown)
+// source: payment/v1/payment.proto
+
+package paymentv1
+
+import (
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+	unsafe "unsafe"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+// PaymentMethod enumerates available payment methods.
+type PaymentMethod int32
+
+const (
+	// Unknown payment method.
+	PaymentMethod_PAYMENT_METHOD_UNSPECIFIED PaymentMethod = 0
+	// Bank card.
+	PaymentMethod_PAYMENT_METHOD_CARD PaymentMethod = 1
+	// Fast Payment System (SBP).
+	PaymentMethod_PAYMENT_METHOD_SBP PaymentMethod = 2
+	// Credit card.
+	PaymentMethod_PAYMENT_METHOD_CREDIT_CARD PaymentMethod = 3
+	// Investor money (internal method).
+	PaymentMethod_PAYMENT_METHOD_INVESTOR_MONEY PaymentMethod = 4
+)
+
+// Enum value maps for PaymentMethod.
+var (
+	PaymentMethod_name = map[int32]string{
+		0: "PAYMENT_METHOD_UNSPECIFIED",
+		1: "PAYMENT_METHOD_CARD",
+		2: "PAYMENT_METHOD_SBP",
+		3: "PAYMENT_METHOD_CREDIT_CARD",
+		4: "PAYMENT_METHOD_INVESTOR_MONEY",
+	}
+	PaymentMethod_value = map[string]int32{
+		"PAYMENT_METHOD_UNSPECIFIED":    0,
+		"PAYMENT_METHOD_CARD":           1,
+		"PAYMENT_METHOD_SBP":            2,
+		"PAYMENT_METHOD_CREDIT_CARD":    3,
+		"PAYMENT_METHOD_INVESTOR_MONEY": 4,
+	}
+)
+
+func (x PaymentMethod) Enum() *PaymentMethod {
+	p := new(PaymentMethod)
+	*p = x
+	return p
+}
+
+func (x PaymentMethod) String() string {
+	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
+}
+
+func (PaymentMethod) Descriptor() protoreflect.EnumDescriptor {
+	return file_payment_v1_payment_proto_enumTypes[0].Descriptor()
+}
+
+func (PaymentMethod) Type() protoreflect.EnumType {
+	return &file_payment_v1_payment_proto_enumTypes[0]
+}
+
+func (x PaymentMethod) Number() protoreflect.EnumNumber {
+	return protoreflect.EnumNumber(x)
+}
+
+// Deprecated: Use PaymentMethod.Descriptor instead.
+func (PaymentMethod) EnumDescriptor() ([]byte, []int) {
+	return file_payment_v1_payment_proto_rawDescGZIP(), []int{0}
+}
+
+// PayOrderRequest contains data for initiating an order payment.
+type PayOrderRequest struct {
+	state protoimpl.MessageState `protogen:"open.v1"`
+	// Order UUID.
+	OrderUuid string `protobuf:"bytes,1,opt,name=order_uuid,json=orderUuid,proto3" json:"order_uuid,omitempty"`
+	// UUID of the user who initiates the payment.
+	UserUuid string `protobuf:"bytes,2,opt,name=user_uuid,json=userUuid,proto3" json:"user_uuid,omitempty"`
+	// Selected payment method.
+	PaymentMethod PaymentMethod `protobuf:"varint,3,opt,name=payment_method,json=paymentMethod,proto3,enum=payment.v1.PaymentMethod" json:"payment_method,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *PayOrderRequest) Reset() {
+	*x = PayOrderRequest{}
+	mi := &file_payment_v1_payment_proto_msgTypes[0]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *PayOrderRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*PayOrderRequest) ProtoMessage() {}
+
+func (x *PayOrderRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_payment_v1_payment_proto_msgTypes[0]
+	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 PayOrderRequest.ProtoReflect.Descriptor instead.
+func (*PayOrderRequest) Descriptor() ([]byte, []int) {
+	return file_payment_v1_payment_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *PayOrderRequest) GetOrderUuid() string {
+	if x != nil {
+		return x.OrderUuid
+	}
+	return ""
+}
+
+func (x *PayOrderRequest) GetUserUuid() string {
+	if x != nil {
+		return x.UserUuid
+	}
+	return ""
+}
+
+func (x *PayOrderRequest) GetPaymentMethod() PaymentMethod {
+	if x != nil {
+		return x.PaymentMethod
+	}
+	return PaymentMethod_PAYMENT_METHOD_UNSPECIFIED
+}
+
+// PayOrderResponse contains the result of payment initiation.
+type PayOrderResponse struct {
+	state protoimpl.MessageState `protogen:"open.v1"`
+	// Payment transaction UUID.
+	TransactionUuid string `protobuf:"bytes,1,opt,name=transaction_uuid,json=transactionUuid,proto3" json:"transaction_uuid,omitempty"`
+	unknownFields   protoimpl.UnknownFields
+	sizeCache       protoimpl.SizeCache
+}
+
+func (x *PayOrderResponse) Reset() {
+	*x = PayOrderResponse{}
+	mi := &file_payment_v1_payment_proto_msgTypes[1]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *PayOrderResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*PayOrderResponse) ProtoMessage() {}
+
+func (x *PayOrderResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_payment_v1_payment_proto_msgTypes[1]
+	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 PayOrderResponse.ProtoReflect.Descriptor instead.
+func (*PayOrderResponse) Descriptor() ([]byte, []int) {
+	return file_payment_v1_payment_proto_rawDescGZIP(), []int{1}
+}
+
+func (x *PayOrderResponse) GetTransactionUuid() string {
+	if x != nil {
+		return x.TransactionUuid
+	}
+	return ""
+}
+
+var File_payment_v1_payment_proto protoreflect.FileDescriptor
+
+const file_payment_v1_payment_proto_rawDesc = "" +
+	"\n" +
+	"\x18payment/v1/payment.proto\x12\n" +
+	"payment.v1\"\x8f\x01\n" +
+	"\x0fPayOrderRequest\x12\x1d\n" +
+	"\n" +
+	"order_uuid\x18\x01 \x01(\tR\torderUuid\x12\x1b\n" +
+	"\tuser_uuid\x18\x02 \x01(\tR\buserUuid\x12@\n" +
+	"\x0epayment_method\x18\x03 \x01(\x0e2\x19.payment.v1.PaymentMethodR\rpaymentMethod\"=\n" +
+	"\x10PayOrderResponse\x12)\n" +
+	"\x10transaction_uuid\x18\x01 \x01(\tR\x0ftransactionUuid*\xa3\x01\n" +
+	"\rPaymentMethod\x12\x1e\n" +
+	"\x1aPAYMENT_METHOD_UNSPECIFIED\x10\x00\x12\x17\n" +
+	"\x13PAYMENT_METHOD_CARD\x10\x01\x12\x16\n" +
+	"\x12PAYMENT_METHOD_SBP\x10\x02\x12\x1e\n" +
+	"\x1aPAYMENT_METHOD_CREDIT_CARD\x10\x03\x12!\n" +
+	"\x1dPAYMENT_METHOD_INVESTOR_MONEY\x10\x042W\n" +
+	"\x0ePaymentService\x12E\n" +
+	"\bPayOrder\x12\x1b.payment.v1.PayOrderRequest\x1a\x1c.payment.v1.PayOrderResponseBGZEgithub.com/qyrlabs/test-backend/shared/pkg/proto/payment/v1;paymentv1b\x06proto3"
+
+var (
+	file_payment_v1_payment_proto_rawDescOnce sync.Once
+	file_payment_v1_payment_proto_rawDescData []byte
+)
+
+func file_payment_v1_payment_proto_rawDescGZIP() []byte {
+	file_payment_v1_payment_proto_rawDescOnce.Do(func() {
+		file_payment_v1_payment_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_payment_v1_payment_proto_rawDesc), len(file_payment_v1_payment_proto_rawDesc)))
+	})
+	return file_payment_v1_payment_proto_rawDescData
+}
+
+var file_payment_v1_payment_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
+var file_payment_v1_payment_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
+var file_payment_v1_payment_proto_goTypes = []any{
+	(PaymentMethod)(0),       // 0: payment.v1.PaymentMethod
+	(*PayOrderRequest)(nil),  // 1: payment.v1.PayOrderRequest
+	(*PayOrderResponse)(nil), // 2: payment.v1.PayOrderResponse
+}
+var file_payment_v1_payment_proto_depIdxs = []int32{
+	0, // 0: payment.v1.PayOrderRequest.payment_method:type_name -> payment.v1.PaymentMethod
+	1, // 1: payment.v1.PaymentService.PayOrder:input_type -> payment.v1.PayOrderRequest
+	2, // 2: payment.v1.PaymentService.PayOrder:output_type -> payment.v1.PayOrderResponse
+	2, // [2:3] is the sub-list for method output_type
+	1, // [1:2] is the sub-list for method input_type
+	1, // [1:1] is the sub-list for extension type_name
+	1, // [1:1] is the sub-list for extension extendee
+	0, // [0:1] is the sub-list for field type_name
+}
+
+func init() { file_payment_v1_payment_proto_init() }
+func file_payment_v1_payment_proto_init() {
+	if File_payment_v1_payment_proto != nil {
+		return
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_payment_v1_payment_proto_rawDesc), len(file_payment_v1_payment_proto_rawDesc)),
+			NumEnums:      1,
+			NumMessages:   2,
+			NumExtensions: 0,
+			NumServices:   1,
+		},
+		GoTypes:           file_payment_v1_payment_proto_goTypes,
+		DependencyIndexes: file_payment_v1_payment_proto_depIdxs,
+		EnumInfos:         file_payment_v1_payment_proto_enumTypes,
+		MessageInfos:      file_payment_v1_payment_proto_msgTypes,
+	}.Build()
+	File_payment_v1_payment_proto = out.File
+	file_payment_v1_payment_proto_goTypes = nil
+	file_payment_v1_payment_proto_depIdxs = nil
+}
diff --git a/shared/pkg/proto/payment/v1/payment_grpc.pb.go b/shared/pkg/proto/payment/v1/payment_grpc.pb.go
new file mode 100644
index 0000000..b25fcec
--- /dev/null
+++ b/shared/pkg/proto/payment/v1/payment_grpc.pb.go
@@ -0,0 +1,127 @@
+// Code generated by protoc-gen-go-grpc. DO NOT EDIT.
+// versions:
+// - protoc-gen-go-grpc v1.6.0
+// - protoc             (unknown)
+// source: payment/v1/payment.proto
+
+package paymentv1
+
+import (
+	context "context"
+	grpc "google.golang.org/grpc"
+	codes "google.golang.org/grpc/codes"
+	status "google.golang.org/grpc/status"
+)
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+// Requires gRPC-Go v1.64.0 or later.
+const _ = grpc.SupportPackageIsVersion9
+
+const (
+	PaymentService_PayOrder_FullMethodName = "/payment.v1.PaymentService/PayOrder"
+)
+
+// PaymentServiceClient is the client API for PaymentService 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.
+//
+// PaymentService provides operations for working with payments.
+type PaymentServiceClient interface {
+	// Initiates order payment.
+	PayOrder(ctx context.Context, in *PayOrderRequest, opts ...grpc.CallOption) (*PayOrderResponse, error)
+}
+
+type paymentServiceClient struct {
+	cc grpc.ClientConnInterface
+}
+
+func NewPaymentServiceClient(cc grpc.ClientConnInterface) PaymentServiceClient {
+	return &paymentServiceClient{cc}
+}
+
+func (c *paymentServiceClient) PayOrder(ctx context.Context, in *PayOrderRequest, opts ...grpc.CallOption) (*PayOrderResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(PayOrderResponse)
+	err := c.cc.Invoke(ctx, PaymentService_PayOrder_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// PaymentServiceServer is the server API for PaymentService service.
+// All implementations must embed UnimplementedPaymentServiceServer
+// for forward compatibility.
+//
+// PaymentService provides operations for working with payments.
+type PaymentServiceServer interface {
+	// Initiates order payment.
+	PayOrder(context.Context, *PayOrderRequest) (*PayOrderResponse, error)
+	mustEmbedUnimplementedPaymentServiceServer()
+}
+
+// UnimplementedPaymentServiceServer must be embedded to have
+// forward compatible implementations.
+//
+// NOTE: this should be embedded by value instead of pointer to avoid a nil
+// pointer dereference when methods are called.
+type UnimplementedPaymentServiceServer struct{}
+
+func (UnimplementedPaymentServiceServer) PayOrder(context.Context, *PayOrderRequest) (*PayOrderResponse, error) {
+	return nil, status.Error(codes.Unimplemented, "method PayOrder not implemented")
+}
+func (UnimplementedPaymentServiceServer) mustEmbedUnimplementedPaymentServiceServer() {}
+func (UnimplementedPaymentServiceServer) testEmbeddedByValue()                        {}
+
+// UnsafePaymentServiceServer may be embedded to opt out of forward compatibility for this service.
+// Use of this interface is not recommended, as added methods to PaymentServiceServer will
+// result in compilation errors.
+type UnsafePaymentServiceServer interface {
+	mustEmbedUnimplementedPaymentServiceServer()
+}
+
+func RegisterPaymentServiceServer(s grpc.ServiceRegistrar, srv PaymentServiceServer) {
+	// If the following call panics, it indicates UnimplementedPaymentServiceServer was
+	// embedded by pointer and is nil.  This will cause panics if an
+	// unimplemented method is ever invoked, so we test this at initialization
+	// time to prevent it from happening at runtime later due to I/O.
+	if t, ok := srv.(interface{ testEmbeddedByValue() }); ok {
+		t.testEmbeddedByValue()
+	}
+	s.RegisterService(&PaymentService_ServiceDesc, srv)
+}
+
+func _PaymentService_PayOrder_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(PayOrderRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(PaymentServiceServer).PayOrder(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: PaymentService_PayOrder_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(PaymentServiceServer).PayOrder(ctx, req.(*PayOrderRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+// PaymentService_ServiceDesc is the grpc.ServiceDesc for PaymentService service.
+// It's only intended for direct use with grpc.RegisterService,
+// and not to be introspected or modified (even as a copy)
+var PaymentService_ServiceDesc = grpc.ServiceDesc{
+	ServiceName: "payment.v1.PaymentService",
+	HandlerType: (*PaymentServiceServer)(nil),
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "PayOrder",
+			Handler:    _PaymentService_PayOrder_Handler,
+		},
+	},
+	Streams:  []grpc.StreamDesc{},
+	Metadata: "payment/v1/payment.proto",
+}
diff --git a/shared/proto/payment/v1/payment.proto b/shared/proto/payment/v1/payment.proto
new file mode 100644
index 0000000..c9615e1
--- /dev/null
+++ b/shared/proto/payment/v1/payment.proto
@@ -0,0 +1,48 @@
+syntax = "proto3";
+
+package payment.v1;
+
+option go_package = "github.com/qyrlabs/test-backend/shared/pkg/proto/payment/v1;paymentv1";
+
+// PaymentService provides operations for working with payments.
+service PaymentService {
+    // Initiates order payment.
+    rpc PayOrder(PayOrderRequest) returns (PayOrderResponse);
+}
+
+// PayOrderRequest contains data for initiating an order payment.
+message PayOrderRequest {
+    // Order UUID.
+    string order_uuid = 1;
+
+    // UUID of the user who initiates the payment.
+    string user_uuid = 2;
+
+    // Selected payment method.
+    PaymentMethod payment_method = 3;
+}
+
+
+// PayOrderResponse contains the result of payment initiation.
+message PayOrderResponse {
+    // Payment transaction UUID.
+    string transaction_uuid = 1;
+}
+
+// PaymentMethod enumerates available payment methods.
+enum PaymentMethod {
+    // Unknown payment method.
+    PAYMENT_METHOD_UNSPECIFIED = 0;
+
+    // Bank card.
+    PAYMENT_METHOD_CARD = 1;
+
+    // Fast Payment System (SBP).
+    PAYMENT_METHOD_SBP = 2;
+
+    // Credit card.
+    PAYMENT_METHOD_CREDIT_CARD = 3;
+
+    // Investor money (internal method).
+    PAYMENT_METHOD_INVESTOR_MONEY = 4;
+}