diff --git a/_examples/golang-basics/example.gen.go b/_examples/golang-basics/example.gen.go
index 79deda0..6e81539 100644
--- a/_examples/golang-basics/example.gen.go
+++ b/_examples/golang-basics/example.gen.go
@@ -12,7 +12,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strings"
@@ -135,50 +134,53 @@ func NewExampleServiceServer(svc ExampleService) WebRPCServer {
 }
 
 func (s *exampleServiceServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	defer func() {
+		// In case of a panic, serve a HTTP 500 error and then panic.
+		if rr := recover(); rr != nil {
+			RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
+			panic(rr)
+		}
+	}()
+
 	ctx := r.Context()
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "ExampleService")
 
-	if r.Method != "POST" {
-		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
-		RespondWithError(w, err)
-		return
-	}
-
+	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
 	case "/rpc/ExampleService/Ping":
-		s.servePing(ctx, w, r)
-		return
+		handler = s.servePingJSON
 	case "/rpc/ExampleService/Status":
-		s.serveStatus(ctx, w, r)
-		return
+		handler = s.serveStatusJSON
 	case "/rpc/ExampleService/Version":
-		s.serveVersion(ctx, w, r)
-		return
+		handler = s.serveVersionJSON
 	case "/rpc/ExampleService/GetUser":
-		s.serveGetUser(ctx, w, r)
-		return
+		handler = s.serveGetUserJSON
 	case "/rpc/ExampleService/FindUser":
-		s.serveFindUser(ctx, w, r)
-		return
+		handler = s.serveFindUserJSON
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRoute, fmt.Errorf("no handler for path %q", r.URL.Path))
 		RespondWithError(w, err)
 		return
 	}
-}
 
-func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
+	if r.Method != "POST" {
+		w.Header().Add("Allow", "POST") // RFC 9110.
+		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
+		RespondWithError(w, err)
+		return
+	}
+
+	contentType := r.Header.Get("Content-Type")
+	if i := strings.Index(contentType, ";"); i >= 0 {
+		contentType = contentType[:i]
 	}
+	contentType = strings.TrimSpace(strings.ToLower(contentType))
 
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
+	switch contentType {
 	case "application/json":
-		s.servePingJSON(ctx, w, r)
+		handler(ctx, w, r)
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
 		RespondWithError(w, err)
@@ -186,21 +188,11 @@ func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWri
 }
 
 func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.ExampleService.Ping(ctx)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
+	// Call service method implementation.
+	err := s.ExampleService.Ping(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -211,50 +203,23 @@ func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.Respons
 	w.Write([]byte("{}"))
 }
 
-func (s *exampleServiceServer) serveStatus(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveStatusJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *exampleServiceServer) serveStatusJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Status")
 
-	// Call service method
-	var ret0 bool
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.Status(ctx)
-	}()
-	respContent := struct {
-		Ret0 bool `json:"status"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Status")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.Status(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 bool `json:"status"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -263,50 +228,23 @@ func (s *exampleServiceServer) serveStatusJSON(ctx context.Context, w http.Respo
 	w.Write(respBody)
 }
 
-func (s *exampleServiceServer) serveVersion(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveVersionJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *exampleServiceServer) serveVersionJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Version")
 
-	// Call service method
-	var ret0 *Version
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.Version(ctx)
-	}()
-	respContent := struct {
-		Ret0 *Version `json:"version"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Version")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.Version(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 *Version `json:"version"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -315,71 +253,39 @@ func (s *exampleServiceServer) serveVersionJSON(ctx context.Context, w http.Resp
 	w.Write(respBody)
 }
 
-func (s *exampleServiceServer) serveGetUser(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetUserJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
+func (s *exampleServiceServer) serveGetUserJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+	reqBody, err := io.ReadAll(r.Body)
+	if err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
+		return
 	}
-}
+	defer r.Body.Close()
 
-func (s *exampleServiceServer) serveGetUserJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
-	reqContent := struct {
+	reqPayload := struct {
 		Arg0 map[string]string `json:"header"`
 		Arg1 uint64            `json:"userID"`
 	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
-	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
+
+	// Call service method implementation.
+	ret0, ret1, err := s.ExampleService.GetUser(ctx, reqPayload.Arg0, reqPayload.Arg1)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
 		RespondWithError(w, err)
 		return
 	}
 
-	// Call service method
-	var ret0 uint32
-	var ret1 *User
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, ret1, err = s.ExampleService.GetUser(ctx, reqContent.Arg0, reqContent.Arg1)
-	}()
-	respContent := struct {
+	respPayload := struct {
 		Ret0 uint32 `json:"code"`
 		Ret1 *User  `json:"user"`
 	}{ret0, ret1}
-
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		RespondWithError(w, err)
-		return
-	}
-	respBody, err := json.Marshal(respContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -388,70 +294,38 @@ func (s *exampleServiceServer) serveGetUserJSON(ctx context.Context, w http.Resp
 	w.Write(respBody)
 }
 
-func (s *exampleServiceServer) serveFindUser(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveFindUserJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
+func (s *exampleServiceServer) serveFindUserJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+	reqBody, err := io.ReadAll(r.Body)
+	if err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
+		return
 	}
-}
+	defer r.Body.Close()
 
-func (s *exampleServiceServer) serveFindUserJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "FindUser")
-	reqContent := struct {
+	reqPayload := struct {
 		Arg0 *SearchFilter `json:"s"`
 	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
-	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "FindUser")
+
+	// Call service method implementation.
+	ret0, ret1, err := s.ExampleService.FindUser(ctx, reqPayload.Arg0)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
 		RespondWithError(w, err)
 		return
 	}
 
-	// Call service method
-	var ret0 string
-	var ret1 *User
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, ret1, err = s.ExampleService.FindUser(ctx, reqContent.Arg0)
-	}()
-	respContent := struct {
+	respPayload := struct {
 		Ret0 string `json:"name"`
 		Ret1 *User  `json:"user"`
 	}{ret0, ret1}
-
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		RespondWithError(w, err)
-		return
-	}
-	respBody, err := json.Marshal(respContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -621,7 +495,7 @@ func doJSONRequest(ctx context.Context, client HTTPClient, url string, in, out i
 	}
 
 	if resp.StatusCode != 200 {
-		respBody, err := ioutil.ReadAll(resp.Body)
+		respBody, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to read server error response body: %w", err))
 		}
@@ -637,7 +511,7 @@ func doJSONRequest(ctx context.Context, client HTTPClient, url string, in, out i
 	}
 
 	if out != nil {
-		respBody, err := ioutil.ReadAll(resp.Body)
+		respBody, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to read response body: %w", err))
 		}
@@ -690,11 +564,8 @@ func (k *contextKey) String() string {
 }
 
 var (
-	// For Client
 	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
-
-	// For Server
-	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
+	HTTPResponseWriterCtxKey       = &contextKey{"HTTPResponseWriter"}
 
 	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}
 
diff --git a/_examples/golang-imports/api.gen.go b/_examples/golang-imports/api.gen.go
index 140517f..92ea34c 100644
--- a/_examples/golang-imports/api.gen.go
+++ b/_examples/golang-imports/api.gen.go
@@ -12,7 +12,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strings"
@@ -105,44 +104,49 @@ func NewExampleAPIServer(svc ExampleAPI) WebRPCServer {
 }
 
 func (s *exampleAPIServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	defer func() {
+		// In case of a panic, serve a HTTP 500 error and then panic.
+		if rr := recover(); rr != nil {
+			RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
+			panic(rr)
+		}
+	}()
+
 	ctx := r.Context()
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "ExampleAPI")
 
-	if r.Method != "POST" {
-		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
-		RespondWithError(w, err)
-		return
-	}
-
+	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
 	case "/rpc/ExampleAPI/Ping":
-		s.servePing(ctx, w, r)
-		return
+		handler = s.servePingJSON
 	case "/rpc/ExampleAPI/Status":
-		s.serveStatus(ctx, w, r)
-		return
+		handler = s.serveStatusJSON
 	case "/rpc/ExampleAPI/GetUsers":
-		s.serveGetUsers(ctx, w, r)
-		return
+		handler = s.serveGetUsersJSON
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRoute, fmt.Errorf("no handler for path %q", r.URL.Path))
 		RespondWithError(w, err)
 		return
 	}
-}
 
-func (s *exampleAPIServer) servePing(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
+	if r.Method != "POST" {
+		w.Header().Add("Allow", "POST") // RFC 9110.
+		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
+		RespondWithError(w, err)
+		return
+	}
+
+	contentType := r.Header.Get("Content-Type")
+	if i := strings.Index(contentType, ";"); i >= 0 {
+		contentType = contentType[:i]
 	}
+	contentType = strings.TrimSpace(strings.ToLower(contentType))
 
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
+	switch contentType {
 	case "application/json":
-		s.servePingJSON(ctx, w, r)
+		handler(ctx, w, r)
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
 		RespondWithError(w, err)
@@ -150,21 +154,11 @@ func (s *exampleAPIServer) servePing(ctx context.Context, w http.ResponseWriter,
 }
 
 func (s *exampleAPIServer) servePingJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.ExampleAPI.Ping(ctx)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
+	// Call service method implementation.
+	err := s.ExampleAPI.Ping(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -175,50 +169,23 @@ func (s *exampleAPIServer) servePingJSON(ctx context.Context, w http.ResponseWri
 	w.Write([]byte("{}"))
 }
 
-func (s *exampleAPIServer) serveStatus(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveStatusJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *exampleAPIServer) serveStatusJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Status")
 
-	// Call service method
-	var ret0 bool
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleAPI.Status(ctx)
-	}()
-	respContent := struct {
-		Ret0 bool `json:"status"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Status")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleAPI.Status(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 bool `json:"status"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -227,52 +194,24 @@ func (s *exampleAPIServer) serveStatusJSON(ctx context.Context, w http.ResponseW
 	w.Write(respBody)
 }
 
-func (s *exampleAPIServer) serveGetUsers(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetUsersJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *exampleAPIServer) serveGetUsersJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUsers")
 
-	// Call service method
-	var ret0 []*User
-	var ret1 *Location
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, ret1, err = s.ExampleAPI.GetUsers(ctx)
-	}()
-	respContent := struct {
-		Ret0 []*User   `json:"users"`
-		Ret1 *Location `json:"location"`
-	}{ret0, ret1}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUsers")
 
+	// Call service method implementation.
+	ret0, ret1, err := s.ExampleAPI.GetUsers(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 []*User   `json:"users"`
+		Ret1 *Location `json:"location"`
+	}{ret0, ret1}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -414,7 +353,7 @@ func doJSONRequest(ctx context.Context, client HTTPClient, url string, in, out i
 	}
 
 	if resp.StatusCode != 200 {
-		respBody, err := ioutil.ReadAll(resp.Body)
+		respBody, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to read server error response body: %w", err))
 		}
@@ -430,7 +369,7 @@ func doJSONRequest(ctx context.Context, client HTTPClient, url string, in, out i
 	}
 
 	if out != nil {
-		respBody, err := ioutil.ReadAll(resp.Body)
+		respBody, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to read response body: %w", err))
 		}
@@ -483,11 +422,8 @@ func (k *contextKey) String() string {
 }
 
 var (
-	// For Client
 	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
-
-	// For Server
-	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
+	HTTPResponseWriterCtxKey       = &contextKey{"HTTPResponseWriter"}
 
 	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}
 
diff --git a/_examples/golang-nodejs/server/server.gen.go b/_examples/golang-nodejs/server/server.gen.go
index 40b70eb..2d77015 100644
--- a/_examples/golang-nodejs/server/server.gen.go
+++ b/_examples/golang-nodejs/server/server.gen.go
@@ -10,7 +10,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -121,41 +121,47 @@ func NewExampleServiceServer(svc ExampleService) WebRPCServer {
 }
 
 func (s *exampleServiceServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	defer func() {
+		// In case of a panic, serve a HTTP 500 error and then panic.
+		if rr := recover(); rr != nil {
+			RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
+			panic(rr)
+		}
+	}()
+
 	ctx := r.Context()
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "ExampleService")
 
-	if r.Method != "POST" {
-		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
-		RespondWithError(w, err)
-		return
-	}
-
+	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
 	case "/rpc/ExampleService/Ping":
-		s.servePing(ctx, w, r)
-		return
+		handler = s.servePingJSON
 	case "/rpc/ExampleService/GetUser":
-		s.serveGetUser(ctx, w, r)
-		return
+		handler = s.serveGetUserJSON
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRoute, fmt.Errorf("no handler for path %q", r.URL.Path))
 		RespondWithError(w, err)
 		return
 	}
-}
 
-func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
+	if r.Method != "POST" {
+		w.Header().Add("Allow", "POST") // RFC 9110.
+		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
+		RespondWithError(w, err)
+		return
+	}
+
+	contentType := r.Header.Get("Content-Type")
+	if i := strings.Index(contentType, ";"); i >= 0 {
+		contentType = contentType[:i]
 	}
+	contentType = strings.TrimSpace(strings.ToLower(contentType))
 
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
+	switch contentType {
 	case "application/json":
-		s.servePingJSON(ctx, w, r)
+		handler(ctx, w, r)
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
 		RespondWithError(w, err)
@@ -163,33 +169,22 @@ func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWri
 }
 
 func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
-	// Call service method
-	var ret0 bool
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.Ping(ctx)
-	}()
-	respContent := struct {
-		Ret0 bool `json:"status"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.Ping(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 bool `json:"status"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -198,68 +193,37 @@ func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.Respons
 	w.Write(respBody)
 }
 
-func (s *exampleServiceServer) serveGetUser(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetUserJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *exampleServiceServer) serveGetUserJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
-	reqContent := struct {
-		Arg0 *GetUserRequest `json:"req"`
-	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
+	reqBody, err := io.ReadAll(r.Body)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
 		return
 	}
 	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
-		RespondWithError(w, err)
+	reqPayload := struct {
+		Arg0 *GetUserRequest `json:"req"`
+	}{}
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
 
-	// Call service method
-	var ret0 *User
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.GetUser(ctx, reqContent.Arg0)
-	}()
-	respContent := struct {
-		Ret0 *User `json:"user"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.GetUser(ctx, reqPayload.Arg0)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 *User `json:"user"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -294,10 +258,6 @@ func (k *contextKey) String() string {
 }
 
 var (
-	// For Client
-	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
-
-	// For Server
 	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
 
 	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}
diff --git a/_examples/hello-webrpc-ts/server/hello_api.gen.go b/_examples/hello-webrpc-ts/server/hello_api.gen.go
index 1180e41..af84e4e 100644
--- a/_examples/hello-webrpc-ts/server/hello_api.gen.go
+++ b/_examples/hello-webrpc-ts/server/hello_api.gen.go
@@ -10,7 +10,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -111,44 +111,49 @@ func NewExampleServiceServer(svc ExampleService) WebRPCServer {
 }
 
 func (s *exampleServiceServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	defer func() {
+		// In case of a panic, serve a HTTP 500 error and then panic.
+		if rr := recover(); rr != nil {
+			RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
+			panic(rr)
+		}
+	}()
+
 	ctx := r.Context()
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "ExampleService")
 
-	if r.Method != "POST" {
-		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
-		RespondWithError(w, err)
-		return
-	}
-
+	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
 	case "/rpc/ExampleService/Ping":
-		s.servePing(ctx, w, r)
-		return
+		handler = s.servePingJSON
 	case "/rpc/ExampleService/GetUser":
-		s.serveGetUser(ctx, w, r)
-		return
+		handler = s.serveGetUserJSON
 	case "/rpc/ExampleService/FindUsers":
-		s.serveFindUsers(ctx, w, r)
-		return
+		handler = s.serveFindUsersJSON
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRoute, fmt.Errorf("no handler for path %q", r.URL.Path))
 		RespondWithError(w, err)
 		return
 	}
-}
 
-func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
+	if r.Method != "POST" {
+		w.Header().Add("Allow", "POST") // RFC 9110.
+		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
+		RespondWithError(w, err)
+		return
+	}
+
+	contentType := r.Header.Get("Content-Type")
+	if i := strings.Index(contentType, ";"); i >= 0 {
+		contentType = contentType[:i]
 	}
+	contentType = strings.TrimSpace(strings.ToLower(contentType))
 
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
+	switch contentType {
 	case "application/json":
-		s.servePingJSON(ctx, w, r)
+		handler(ctx, w, r)
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
 		RespondWithError(w, err)
@@ -156,33 +161,22 @@ func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWri
 }
 
 func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
-	// Call service method
-	var ret0 bool
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.Ping(ctx)
-	}()
-	respContent := struct {
-		Ret0 bool `json:"status"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.Ping(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 bool `json:"status"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -191,68 +185,37 @@ func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.Respons
 	w.Write(respBody)
 }
 
-func (s *exampleServiceServer) serveGetUser(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetUserJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *exampleServiceServer) serveGetUserJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
-	reqContent := struct {
-		Arg0 uint64 `json:"userID"`
-	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
+	reqBody, err := io.ReadAll(r.Body)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
 		return
 	}
 	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
-		RespondWithError(w, err)
+	reqPayload := struct {
+		Arg0 uint64 `json:"userID"`
+	}{}
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
 
-	// Call service method
-	var ret0 *User
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.GetUser(ctx, reqContent.Arg0)
-	}()
-	respContent := struct {
-		Ret0 *User `json:"user"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.GetUser(ctx, reqPayload.Arg0)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 *User `json:"user"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -261,70 +224,38 @@ func (s *exampleServiceServer) serveGetUserJSON(ctx context.Context, w http.Resp
 	w.Write(respBody)
 }
 
-func (s *exampleServiceServer) serveFindUsers(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveFindUsersJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
+func (s *exampleServiceServer) serveFindUsersJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+	reqBody, err := io.ReadAll(r.Body)
+	if err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
+		return
 	}
-}
+	defer r.Body.Close()
 
-func (s *exampleServiceServer) serveFindUsersJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "FindUsers")
-	reqContent := struct {
+	reqPayload := struct {
 		Arg0 string `json:"q"`
 	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
-	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "FindUsers")
+
+	// Call service method implementation.
+	ret0, ret1, err := s.ExampleService.FindUsers(ctx, reqPayload.Arg0)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
 		RespondWithError(w, err)
 		return
 	}
 
-	// Call service method
-	var ret0 *Page
-	var ret1 []*User
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, ret1, err = s.ExampleService.FindUsers(ctx, reqContent.Arg0)
-	}()
-	respContent := struct {
+	respPayload := struct {
 		Ret0 *Page   `json:"page"`
 		Ret1 []*User `json:"users"`
 	}{ret0, ret1}
-
-	if err != nil {
-		RespondWithError(w, err)
-		return
-	}
-	respBody, err := json.Marshal(respContent)
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -359,10 +290,6 @@ func (k *contextKey) String() string {
 }
 
 var (
-	// For Client
-	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
-
-	// For Server
 	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
 
 	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}
diff --git a/_examples/hello-webrpc/server/hello_api.gen.go b/_examples/hello-webrpc/server/hello_api.gen.go
index 39fe2d3..9751512 100644
--- a/_examples/hello-webrpc/server/hello_api.gen.go
+++ b/_examples/hello-webrpc/server/hello_api.gen.go
@@ -10,7 +10,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -105,41 +105,47 @@ func NewExampleServiceServer(svc ExampleService) WebRPCServer {
 }
 
 func (s *exampleServiceServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	defer func() {
+		// In case of a panic, serve a HTTP 500 error and then panic.
+		if rr := recover(); rr != nil {
+			RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
+			panic(rr)
+		}
+	}()
+
 	ctx := r.Context()
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "ExampleService")
 
-	if r.Method != "POST" {
-		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
-		RespondWithError(w, err)
-		return
-	}
-
+	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
 	case "/rpc/ExampleService/Ping":
-		s.servePing(ctx, w, r)
-		return
+		handler = s.servePingJSON
 	case "/rpc/ExampleService/GetUser":
-		s.serveGetUser(ctx, w, r)
-		return
+		handler = s.serveGetUserJSON
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRoute, fmt.Errorf("no handler for path %q", r.URL.Path))
 		RespondWithError(w, err)
 		return
 	}
-}
 
-func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
+	if r.Method != "POST" {
+		w.Header().Add("Allow", "POST") // RFC 9110.
+		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
+		RespondWithError(w, err)
+		return
+	}
+
+	contentType := r.Header.Get("Content-Type")
+	if i := strings.Index(contentType, ";"); i >= 0 {
+		contentType = contentType[:i]
 	}
+	contentType = strings.TrimSpace(strings.ToLower(contentType))
 
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
+	switch contentType {
 	case "application/json":
-		s.servePingJSON(ctx, w, r)
+		handler(ctx, w, r)
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
 		RespondWithError(w, err)
@@ -147,33 +153,22 @@ func (s *exampleServiceServer) servePing(ctx context.Context, w http.ResponseWri
 }
 
 func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
-	// Call service method
-	var ret0 bool
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.Ping(ctx)
-	}()
-	respContent := struct {
-		Ret0 bool `json:"status"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "Ping")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.Ping(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 bool `json:"status"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -182,68 +177,37 @@ func (s *exampleServiceServer) servePingJSON(ctx context.Context, w http.Respons
 	w.Write(respBody)
 }
 
-func (s *exampleServiceServer) serveGetUser(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetUserJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *exampleServiceServer) serveGetUserJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
-	reqContent := struct {
-		Arg0 uint64 `json:"userID"`
-	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
+	reqBody, err := io.ReadAll(r.Body)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
 		return
 	}
 	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
-		RespondWithError(w, err)
+	reqPayload := struct {
+		Arg0 uint64 `json:"userID"`
+	}{}
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
 
-	// Call service method
-	var ret0 *User
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.ExampleService.GetUser(ctx, reqContent.Arg0)
-	}()
-	respContent := struct {
-		Ret0 *User `json:"user"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetUser")
 
+	// Call service method implementation.
+	ret0, err := s.ExampleService.GetUser(ctx, reqPayload.Arg0)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 *User `json:"user"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -278,10 +242,6 @@ func (k *contextKey) String() string {
 }
 
 var (
-	// For Client
-	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
-
-	// For Server
 	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
 
 	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}
diff --git a/tests/client/client.gen.go b/tests/client/client.gen.go
index a25c016..efe301e 100644
--- a/tests/client/client.gen.go
+++ b/tests/client/client.gen.go
@@ -12,7 +12,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 )
@@ -296,7 +295,7 @@ func doJSONRequest(ctx context.Context, client HTTPClient, url string, in, out i
 	}
 
 	if resp.StatusCode != 200 {
-		respBody, err := ioutil.ReadAll(resp.Body)
+		respBody, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to read server error response body: %w", err))
 		}
@@ -312,7 +311,7 @@ func doJSONRequest(ctx context.Context, client HTTPClient, url string, in, out i
 	}
 
 	if out != nil {
-		respBody, err := ioutil.ReadAll(resp.Body)
+		respBody, err := io.ReadAll(resp.Body)
 		if err != nil {
 			return ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to read response body: %w", err))
 		}
@@ -365,12 +364,8 @@ func (k *contextKey) String() string {
 }
 
 var (
-	// For Client
 	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
 
-	// For Server
-	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
-
 	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}
 
 	ServiceNameCtxKey = &contextKey{"ServiceName"}
diff --git a/tests/server/server.gen.go b/tests/server/server.gen.go
index 9ab1f52..d52a7c4 100644
--- a/tests/server/server.gen.go
+++ b/tests/server/server.gen.go
@@ -10,7 +10,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strings"
 )
@@ -133,62 +133,61 @@ func NewTestApiServer(svc TestApi) WebRPCServer {
 }
 
 func (s *testApiServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	defer func() {
+		// In case of a panic, serve a HTTP 500 error and then panic.
+		if rr := recover(); rr != nil {
+			RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
+			panic(rr)
+		}
+	}()
+
 	ctx := r.Context()
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "TestApi")
 
-	if r.Method != "POST" {
-		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
-		RespondWithError(w, err)
-		return
-	}
-
+	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
 	case "/rpc/TestApi/GetEmpty":
-		s.serveGetEmpty(ctx, w, r)
-		return
+		handler = s.serveGetEmptyJSON
 	case "/rpc/TestApi/GetError":
-		s.serveGetError(ctx, w, r)
-		return
+		handler = s.serveGetErrorJSON
 	case "/rpc/TestApi/GetOne":
-		s.serveGetOne(ctx, w, r)
-		return
+		handler = s.serveGetOneJSON
 	case "/rpc/TestApi/SendOne":
-		s.serveSendOne(ctx, w, r)
-		return
+		handler = s.serveSendOneJSON
 	case "/rpc/TestApi/GetMulti":
-		s.serveGetMulti(ctx, w, r)
-		return
+		handler = s.serveGetMultiJSON
 	case "/rpc/TestApi/SendMulti":
-		s.serveSendMulti(ctx, w, r)
-		return
+		handler = s.serveSendMultiJSON
 	case "/rpc/TestApi/GetComplex":
-		s.serveGetComplex(ctx, w, r)
-		return
+		handler = s.serveGetComplexJSON
 	case "/rpc/TestApi/SendComplex":
-		s.serveSendComplex(ctx, w, r)
-		return
+		handler = s.serveSendComplexJSON
 	case "/rpc/TestApi/GetSchemaError":
-		s.serveGetSchemaError(ctx, w, r)
-		return
+		handler = s.serveGetSchemaErrorJSON
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRoute, fmt.Errorf("no handler for path %q", r.URL.Path))
 		RespondWithError(w, err)
 		return
 	}
-}
 
-func (s *testApiServer) serveGetEmpty(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
+	if r.Method != "POST" {
+		w.Header().Add("Allow", "POST") // RFC 9110.
+		err := ErrorWithCause(ErrWebrpcBadMethod, fmt.Errorf("unsupported method %q (only POST is allowed)", r.Method))
+		RespondWithError(w, err)
+		return
 	}
 
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
+	contentType := r.Header.Get("Content-Type")
+	if i := strings.Index(contentType, ";"); i >= 0 {
+		contentType = contentType[:i]
+	}
+	contentType = strings.TrimSpace(strings.ToLower(contentType))
+
+	switch contentType {
 	case "application/json":
-		s.serveGetEmptyJSON(ctx, w, r)
+		handler(ctx, w, r)
 	default:
 		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
 		RespondWithError(w, err)
@@ -196,21 +195,11 @@ func (s *testApiServer) serveGetEmpty(ctx context.Context, w http.ResponseWriter
 }
 
 func (s *testApiServer) serveGetEmptyJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetEmpty")
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.TestApi.GetEmpty(ctx)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetEmpty")
 
+	// Call service method implementation.
+	err := s.TestApi.GetEmpty(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -221,38 +210,12 @@ func (s *testApiServer) serveGetEmptyJSON(ctx context.Context, w http.ResponseWr
 	w.Write([]byte("{}"))
 }
 
-func (s *testApiServer) serveGetError(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetErrorJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *testApiServer) serveGetErrorJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetError")
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.TestApi.GetError(ctx)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetError")
 
+	// Call service method implementation.
+	err := s.TestApi.GetError(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -263,50 +226,23 @@ func (s *testApiServer) serveGetErrorJSON(ctx context.Context, w http.ResponseWr
 	w.Write([]byte("{}"))
 }
 
-func (s *testApiServer) serveGetOne(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetOneJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *testApiServer) serveGetOneJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetOne")
 
-	// Call service method
-	var ret0 *Simple
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.TestApi.GetOne(ctx)
-	}()
-	respContent := struct {
-		Ret0 *Simple `json:"one"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetOne")
 
+	// Call service method implementation.
+	ret0, err := s.TestApi.GetOne(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 *Simple `json:"one"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -315,56 +251,26 @@ func (s *testApiServer) serveGetOneJSON(ctx context.Context, w http.ResponseWrit
 	w.Write(respBody)
 }
 
-func (s *testApiServer) serveSendOne(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveSendOneJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *testApiServer) serveSendOneJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "SendOne")
-	reqContent := struct {
-		Arg0 *Simple `json:"one"`
-	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
+	reqBody, err := io.ReadAll(r.Body)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
 		return
 	}
 	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
-		RespondWithError(w, err)
+	reqPayload := struct {
+		Arg0 *Simple `json:"one"`
+	}{}
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.TestApi.SendOne(ctx, reqContent.Arg0)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "SendOne")
 
+	// Call service method implementation.
+	err = s.TestApi.SendOne(ctx, reqPayload.Arg0)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -375,54 +281,25 @@ func (s *testApiServer) serveSendOneJSON(ctx context.Context, w http.ResponseWri
 	w.Write([]byte("{}"))
 }
 
-func (s *testApiServer) serveGetMulti(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
+func (s *testApiServer) serveGetMultiJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
 
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetMultiJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetMulti")
+
+	// Call service method implementation.
+	ret0, ret1, ret2, err := s.TestApi.GetMulti(ctx)
+	if err != nil {
 		RespondWithError(w, err)
+		return
 	}
-}
-
-func (s *testApiServer) serveGetMultiJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetMulti")
 
-	// Call service method
-	var ret0 *Simple
-	var ret1 *Simple
-	var ret2 *Simple
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, ret1, ret2, err = s.TestApi.GetMulti(ctx)
-	}()
-	respContent := struct {
+	respPayload := struct {
 		Ret0 *Simple `json:"one"`
 		Ret1 *Simple `json:"two"`
 		Ret2 *Simple `json:"three"`
 	}{ret0, ret1, ret2}
-
-	if err != nil {
-		RespondWithError(w, err)
-		return
-	}
-	respBody, err := json.Marshal(respContent)
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -431,58 +308,28 @@ func (s *testApiServer) serveGetMultiJSON(ctx context.Context, w http.ResponseWr
 	w.Write(respBody)
 }
 
-func (s *testApiServer) serveSendMulti(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveSendMultiJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *testApiServer) serveSendMultiJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "SendMulti")
-	reqContent := struct {
-		Arg0 *Simple `json:"one"`
-		Arg1 *Simple `json:"two"`
-		Arg2 *Simple `json:"three"`
-	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
+	reqBody, err := io.ReadAll(r.Body)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
 		return
 	}
 	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
-		RespondWithError(w, err)
+	reqPayload := struct {
+		Arg0 *Simple `json:"one"`
+		Arg1 *Simple `json:"two"`
+		Arg2 *Simple `json:"three"`
+	}{}
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.TestApi.SendMulti(ctx, reqContent.Arg0, reqContent.Arg1, reqContent.Arg2)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "SendMulti")
 
+	// Call service method implementation.
+	err = s.TestApi.SendMulti(ctx, reqPayload.Arg0, reqPayload.Arg1, reqPayload.Arg2)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -493,50 +340,23 @@ func (s *testApiServer) serveSendMultiJSON(ctx context.Context, w http.ResponseW
 	w.Write([]byte("{}"))
 }
 
-func (s *testApiServer) serveGetComplex(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetComplexJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *testApiServer) serveGetComplexJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetComplex")
 
-	// Call service method
-	var ret0 *Complex
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		ret0, err = s.TestApi.GetComplex(ctx)
-	}()
-	respContent := struct {
-		Ret0 *Complex `json:"complex"`
-	}{ret0}
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetComplex")
 
+	// Call service method implementation.
+	ret0, err := s.TestApi.GetComplex(ctx)
 	if err != nil {
 		RespondWithError(w, err)
 		return
 	}
-	respBody, err := json.Marshal(respContent)
+
+	respPayload := struct {
+		Ret0 *Complex `json:"complex"`
+	}{ret0}
+	respBody, err := json.Marshal(respPayload)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadResponse, fmt.Errorf("failed to marshal json response: %w", err)))
 		return
 	}
 
@@ -545,56 +365,26 @@ func (s *testApiServer) serveGetComplexJSON(ctx context.Context, w http.Response
 	w.Write(respBody)
 }
 
-func (s *testApiServer) serveSendComplex(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveSendComplexJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *testApiServer) serveSendComplexJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "SendComplex")
-	reqContent := struct {
-		Arg0 *Complex `json:"complex"`
-	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
+	reqBody, err := io.ReadAll(r.Body)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
 		return
 	}
 	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
-		RespondWithError(w, err)
+	reqPayload := struct {
+		Arg0 *Complex `json:"complex"`
+	}{}
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.TestApi.SendComplex(ctx, reqContent.Arg0)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "SendComplex")
 
+	// Call service method implementation.
+	err = s.TestApi.SendComplex(ctx, reqPayload.Arg0)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -605,56 +395,26 @@ func (s *testApiServer) serveSendComplexJSON(ctx context.Context, w http.Respons
 	w.Write([]byte("{}"))
 }
 
-func (s *testApiServer) serveGetSchemaError(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	header := r.Header.Get("Content-Type")
-	i := strings.Index(header, ";")
-	if i == -1 {
-		i = len(header)
-	}
-
-	switch strings.TrimSpace(strings.ToLower(header[:i])) {
-	case "application/json":
-		s.serveGetSchemaErrorJSON(ctx, w, r)
-	default:
-		err := ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("unexpected Content-Type: %q", r.Header.Get("Content-Type")))
-		RespondWithError(w, err)
-	}
-}
-
 func (s *testApiServer) serveGetSchemaErrorJSON(ctx context.Context, w http.ResponseWriter, r *http.Request) {
-	var err error
-	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetSchemaError")
-	reqContent := struct {
-		Arg0 int `json:"code"`
-	}{}
-
-	reqBody, err := ioutil.ReadAll(r.Body)
+	reqBody, err := io.ReadAll(r.Body)
 	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err))
-		RespondWithError(w, err)
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to read request data: %w", err)))
 		return
 	}
 	defer r.Body.Close()
 
-	err = json.Unmarshal(reqBody, &reqContent)
-	if err != nil {
-		err = ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err))
-		RespondWithError(w, err)
+	reqPayload := struct {
+		Arg0 int `json:"code"`
+	}{}
+	if err := json.Unmarshal(reqBody, &reqPayload); err != nil {
+		RespondWithError(w, ErrorWithCause(ErrWebrpcBadRequest, fmt.Errorf("failed to unmarshal request data: %w", err)))
 		return
 	}
 
-	// Call service method
-	func() {
-		defer func() {
-			// In case of a panic, serve a 500 error and then panic.
-			if rr := recover(); rr != nil {
-				RespondWithError(w, ErrorWithCause(ErrWebrpcServerPanic, fmt.Errorf("%v", rr)))
-				panic(rr)
-			}
-		}()
-		err = s.TestApi.GetSchemaError(ctx, reqContent.Arg0)
-	}()
+	ctx = context.WithValue(ctx, MethodNameCtxKey, "GetSchemaError")
 
+	// Call service method implementation.
+	err = s.TestApi.GetSchemaError(ctx, reqPayload.Arg0)
 	if err != nil {
 		RespondWithError(w, err)
 		return
@@ -691,10 +451,6 @@ func (k *contextKey) String() string {
 }
 
 var (
-	// For Client
-	HTTPClientRequestHeadersCtxKey = &contextKey{"HTTPClientRequestHeaders"}
-
-	// For Server
 	HTTPResponseWriterCtxKey = &contextKey{"HTTPResponseWriter"}
 
 	HTTPRequestCtxKey = &contextKey{"HTTPRequest"}