diff --git a/js-sdk/node-example/src/_aqua/calc.ts b/js-sdk/node-example/src/_aqua/calc.ts
index 744aa36..ca70883 100644
--- a/js-sdk/node-example/src/_aqua/calc.ts
+++ b/js-sdk/node-example/src/_aqua/calc.ts
@@ -3,7 +3,7 @@
  * This file is auto-generated. Do not edit manually: changes may be erased.
  * Generated by Aqua compiler: https://github.com/fluencelabs/aqua/.
  * If you find any bugs, please write an issue on GitHub: https://github.com/fluencelabs/aqua/issues
- * Aqua version: 0.2.0-SNAPSHOT
+ * Aqua version: 0.2.2-SNAPSHOT
  *
  */
 import { FluencePeer } from "@fluencelabs/fluence";
@@ -16,47 +16,22 @@ import {
 
 // Services
 
-export function registerCalc(service: {
-  add: (n: number, callParams: CallParams<"n">) => Promise<void>;
-  divide: (n: number, callParams: CallParams<"n">) => Promise<void>;
-  getResult: (callParams: CallParams<null>) => Promise<number>;
-  multiply: (n: number, callParams: CallParams<"n">) => Promise<void>;
-  reset: (callParams: CallParams<null>) => Promise<void>;
-  subtract: (n: number, callParams: CallParams<"n">) => Promise<void>;
-}): void;
-export function registerCalc(
-  serviceId: string,
-  service: {
-    add: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    divide: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    getResult: (callParams: CallParams<null>) => Promise<number>;
-    multiply: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    reset: (callParams: CallParams<null>) => Promise<void>;
-    subtract: (n: number, callParams: CallParams<"n">) => Promise<void>;
-  }
-): void;
-export function registerCalc(
-  peer: FluencePeer,
-  service: {
-    add: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    divide: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    getResult: (callParams: CallParams<null>) => Promise<number>;
-    multiply: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    reset: (callParams: CallParams<null>) => Promise<void>;
-    subtract: (n: number, callParams: CallParams<"n">) => Promise<void>;
-  }
-): void;
+export interface CalcDef {
+  add: (n: number, callParams: CallParams<"n">) => Promise<void> | void;
+  divide: (n: number, callParams: CallParams<"n">) => Promise<void> | void;
+  getResult: (callParams: CallParams<null>) => Promise<number> | number;
+  multiply: (n: number, callParams: CallParams<"n">) => Promise<void> | void;
+  reset: (callParams: CallParams<null>) => Promise<void> | void;
+  subtract: (n: number, callParams: CallParams<"n">) => Promise<void> | void;
+}
+
+export function registerCalc(service: CalcDef): void;
+export function registerCalc(serviceId: string, service: CalcDef): void;
+export function registerCalc(peer: FluencePeer, service: CalcDef): void;
 export function registerCalc(
   peer: FluencePeer,
   serviceId: string,
-  service: {
-    add: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    divide: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    getResult: (callParams: CallParams<null>) => Promise<number>;
-    multiply: (n: number, callParams: CallParams<"n">) => Promise<void>;
-    reset: (callParams: CallParams<null>) => Promise<void>;
-    subtract: (n: number, callParams: CallParams<"n">) => Promise<void>;
-  }
+  service: CalcDef
 ): void;
 export function registerCalc(...args) {
   let peer: FluencePeer;
diff --git a/js-sdk/node-example/src/index.ts b/js-sdk/node-example/src/index.ts
index 29e4373..41c90dc 100644
--- a/js-sdk/node-example/src/index.ts
+++ b/js-sdk/node-example/src/index.ts
@@ -1,30 +1,30 @@
 import { FluencePeer } from "@fluencelabs/fluence";
-import { registerCalc, demoCalculation } from "./_aqua/calc";
+import { registerCalc, CalcDef, demoCalculation } from "./_aqua/calc";
 
-class Calc {
+class Calc implements CalcDef {
   private _state: number = 0;
 
-  async add(n: number) {
+  add(n: number) {
     this._state += n;
   }
 
-  async subtract(n: number) {
+  subtract(n: number) {
     this._state -= n;
   }
 
-  async multiply(n: number) {
+  multiply(n: number) {
     this._state *= n;
   }
 
-  async divide(n: number) {
+  divide(n: number) {
     this._state /= n;
   }
 
-  async reset() {
+  reset() {
     this._state = 0;
   }
 
-  async getResult() {
+  getResult() {
     return this._state;
   }
 }