diff --git a/api/adapter.go b/api/adapter.go
new file mode 100644
index 0000000..08a9959
--- /dev/null
+++ b/api/adapter.go
@@ -0,0 +1,6 @@
+package api
+
+import "net/http"
+
+// Adapter to encapsulate incoming requests
+type Adapter func(http.HandlerFunc) http.HandlerFunc
diff --git a/builder.go b/builder.go
index 65c5240..f65fefa 100644
--- a/builder.go
+++ b/builder.go
@@ -5,6 +5,7 @@ import (
 	"io"
 	"net/http"
 
+	"git.xdrm.io/go/aicra/api"
 	"git.xdrm.io/go/aicra/datatype"
 	"git.xdrm.io/go/aicra/internal/config"
 	"git.xdrm.io/go/aicra/internal/dynfunc"
@@ -14,6 +15,7 @@ import (
 type Builder struct {
 	conf     *config.Server
 	handlers []*apiHandler
+	adapters []api.Adapter
 }
 
 // represents an api handler (method-pattern combination)
@@ -31,9 +33,23 @@ func (b *Builder) AddType(t datatype.T) {
 	if b.conf.Services != nil {
 		panic(errLateType)
 	}
+	if b.conf.Types == nil {
+		b.conf.Types = make([]datatype.T, 0)
+	}
 	b.conf.Types = append(b.conf.Types, t)
 }
 
+// Use adds an http adapter (middleware)
+func (b *Builder) Use(adapter api.Adapter) {
+	if b.conf == nil {
+		b.conf = &config.Server{}
+	}
+	if b.adapters == nil {
+		b.adapters = make([]api.Adapter, 0)
+	}
+	b.adapters = append(b.adapters, adapter)
+}
+
 // Setup the builder with its api definition file
 // panics if already setup
 func (b *Builder) Setup(r io.Reader) error {
diff --git a/handler.go b/handler.go
index e85fe49..b6feeb3 100644
--- a/handler.go
+++ b/handler.go
@@ -1,7 +1,6 @@
 package aicra
 
 import (
-	"log"
 	"net/http"
 
 	"git.xdrm.io/go/aicra/api"
@@ -12,17 +11,17 @@ import (
 // Handler wraps the builder to handle requests
 type Handler Builder
 
-// ServeHTTP implements http.Handler
+// ServeHTTP implements http.Handler and wraps it in middlewares (adapters)
 func (s Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	defer func() {
-		if rc := recover(); rc != nil {
-			log.Printf("recovering request: %s\n", rc)
-			// try to send error response
-			api.EmptyResponse().WithError(api.ErrUncallableService).ServeHTTP(w, r)
-		}
-	}()
-	defer r.Body.Close()
+	var h = http.HandlerFunc(s.handleRequest)
 
+	for _, adapter := range s.adapters {
+		h = adapter(h)
+	}
+	h(w, r)
+}
+
+func (s Handler) handleRequest(w http.ResponseWriter, r *http.Request) {
 	// 1. find a matching service from config
 	var service = s.conf.Find(r)
 	if service == nil {
diff --git a/internal/dynfunc/handler.go b/internal/dynfunc/handler.go
index c12069c..4e36b71 100644
--- a/internal/dynfunc/handler.go
+++ b/internal/dynfunc/handler.go
@@ -2,6 +2,7 @@ package dynfunc
 
 import (
 	"fmt"
+	"log"
 	"reflect"
 
 	"git.xdrm.io/go/aicra/api"
@@ -70,6 +71,29 @@ func (h *Handler) Handle(data map[string]interface{}) (map[string]interface{}, a
 			if !inData {
 				continue
 			}
+
+			var refvalue = reflect.ValueOf(value)
+
+			// T to pointer of T
+			if field.Kind() == reflect.Ptr {
+				var ptrType = field.Type().Elem()
+
+				if !refvalue.Type().ConvertibleTo(ptrType) {
+					log.Printf("Cannot convert %v into %v", refvalue.Type(), ptrType)
+					return nil, api.ErrUncallableService
+				}
+
+				ptr := reflect.New(ptrType)
+				ptr.Elem().Set(reflect.ValueOf(value).Convert(ptrType))
+
+				field.Set(ptr)
+				continue
+			}
+			if !reflect.ValueOf(value).Type().ConvertibleTo(field.Type()) {
+				log.Printf("Cannot convert %v into %v", reflect.ValueOf(value).Type(), field.Type())
+				return nil, api.ErrUncallableService
+			}
+
 			field.Set(reflect.ValueOf(value).Convert(field.Type()))
 		}
 		callArgs = append(callArgs, callStruct)