diff --git a/Swift/Methods.swift.twig b/Swift/Methods.swift.twig
index ef4952c..eceb90f 100644
--- a/Swift/Methods.swift.twig
+++ b/Swift/Methods.swift.twig
@@ -2,9 +2,9 @@ import LeadKit
 import RxSwift
 import Alamofire
 
-{% set serviceName = concat(networkServiceName, "NetworkService") -%}
+{% set protocolName = concat(networkServiceName, "NetworkProtocol") -%}
 
-extension {{ serviceName }} {
+extension {{ protocolName }} {
 
     {% for method in methods %}
     {%- include 'blocks/method/method-func.twig' with { method: method, isStatic: false } %}
@@ -12,11 +12,11 @@ extension {{ serviceName }} {
     {% endfor %}
 }
 
-extension Singleton where Self: {{ serviceName }} {
+extension Singleton where Self: {{ protocolName }} {
 
     {% for method in methods %}
     {%- include 'blocks/method/method-func.twig' with { method: method, isStatic: true } %}
-
+    
     {% endfor %}
 }
-{{ "\n" }}
\ No newline at end of file
+{{ "\n" }}
diff --git a/Swift/NetworkService.swift.twig b/Swift/NetworkService.swift.twig
index b0949bf..2ef26f8 100644
--- a/Swift/NetworkService.swift.twig
+++ b/Swift/NetworkService.swift.twig
@@ -3,7 +3,23 @@ import RxSwift
 import Alamofire
 
 {% set serviceName = concat(networkServiceName, "NetworkService") -%}
-class {{ serviceName }}: NetworkService {
+{% set protocolName = concat(networkServiceName, "NetworkProtocol") -%}
+
+protocol {{ protocolName }} {
+
+    func apiRequest<T: Decodable>(with parameters: ApiRequestParameters, decoder: JSONDecoder) -> Single<T>
+    func apiRequestParameters(relativeUrl: String,
+                              method: HTTPMethod,
+                              parameters: Parameters?,
+                              requestEncoding: ParameterEncoding?,
+                              requestHeaders: HTTPHeaders?) -> ApiRequestParameters
+
+    {% for method in methods %}
+    {%- include 'blocks/method/method-declaration.twig' with { method: method, isStatic: false } -%}
+    {% endfor %}
+}
+
+class {{ serviceName }}: NetworkService, {{ protocolName }} {
 
     static let apiBaseUrl = "{{ apiUrl }}"
 
diff --git a/Swift/blocks/method/method-declaration.twig b/Swift/blocks/method/method-declaration.twig
new file mode 100644
index 0000000..d963da6
--- /dev/null
+++ b/Swift/blocks/method/method-declaration.twig
@@ -0,0 +1,12 @@
+{%- import '../../macroses/common.utils.twig' as utils -%}
+
+{%- if (method.bodyType is not null) -%}
+  {%- set bodyParamName = utils.decapitalize(method.bodyType.type.typeName) -%}
+  {%- set bodyTypeName = method.bodyType.type.typeName -%}
+
+  {%- set hasBody = true -%}
+{%- endif -%}
+
+{%- set funcName = utils.decapitalize(method.name) -%}
+
+{{ isStatic ? "static " : "" }}func {{ funcName }}({%- if hasBody -%}{{ bodyParamName }}: {{ bodyTypeName }},{{ " " }}{%- endif -%}requestEncoding: ParameterEncoding?, requestHeaders: HTTPHeaders?) -> Single<{{ method.responseType.type.typeName }}>
diff --git a/Swift/blocks/method/method-func.twig b/Swift/blocks/method/method-func.twig
index 018dc50..f7d8c07 100644
--- a/Swift/blocks/method/method-func.twig
+++ b/Swift/blocks/method/method-func.twig
@@ -26,6 +26,6 @@
                                               requestEncoding: requestEncoding,
                                               requestHeaders: requestHeaders)
 
-          return apiRequest(with: parameters)
+          return apiRequest(with: parameters, decoder: JSONDecoder())
         {%- endif %}
     }