diff --git a/examples/example-pure-js/src/index.ts b/examples/example-pure-js/src/index.ts
index d18389f..bc0513f 100644
--- a/examples/example-pure-js/src/index.ts
+++ b/examples/example-pure-js/src/index.ts
@@ -78,6 +78,9 @@ async function main() {
         provider: wcProvider as any,
       },
     },
+    customHeaders: {
+      'x-qubic-client-version': '0.0.0-alpha.0',
+    },
   };
 
   const qubicConnect = new QubicConnect(SDK_CONFIG);
diff --git a/packages/core/src/QubicConnect.ts b/packages/core/src/QubicConnect.ts
index 4d63335..5cd9498 100644
--- a/packages/core/src/QubicConnect.ts
+++ b/packages/core/src/QubicConnect.ts
@@ -105,6 +105,7 @@ export class QubicConnect {
       disableOpenExternalBrowserWhenLineIab = false,
       trackGaSettings = [],
       autoLoginInWalletIabType = 'enable',
+      customHeaders = {},
     } = config;
     if (!apiKey) {
       throw Error('new QubicConnect should have key');
@@ -127,6 +128,7 @@ export class QubicConnect {
       disableOpenExternalBrowserWhenLineIab,
       trackGaSettings,
       autoLoginInWalletIabType,
+      customHeaders,
     };
 
     QubicConnect.checkProviderOptions(config?.providerOptions);
@@ -135,6 +137,7 @@ export class QubicConnect {
       apiKey,
       apiSecret,
       apiUrl,
+      customHeaders,
     });
 
     this.requestGraphql = createRequestGraphql({
@@ -148,6 +151,7 @@ export class QubicConnect {
       apiKey,
       apiSecret,
       apiUrl: marketApiUrl,
+      customHeaders,
       onUnauthenticated: () => this.handleLogout(null),
     });
 
diff --git a/packages/core/src/types/QubicConnectConfig.ts b/packages/core/src/types/QubicConnectConfig.ts
index 9f8fb33..87c1d3a 100644
--- a/packages/core/src/types/QubicConnectConfig.ts
+++ b/packages/core/src/types/QubicConnectConfig.ts
@@ -20,6 +20,8 @@ export interface QubicConnectConfig {
   // # fast login
   // authRedirectUrl where have different type of wallet
   authRedirectUrl?: string;
+
+  customHeaders?: Record<string, string>;
 }
 
 export interface InternalQubicConnectConfig extends Omit<Required<QubicConnectConfig>, 'providerOptions'> {
diff --git a/packages/core/src/utils/graphql.ts b/packages/core/src/utils/graphql.ts
index 903cd30..5f1ff0e 100644
--- a/packages/core/src/utils/graphql.ts
+++ b/packages/core/src/utils/graphql.ts
@@ -63,18 +63,16 @@ function parseGraphqlErrors(errorResponse: string): Array<{
   }
 }
 
+type CreateRequestGraphqlProps = {
+  apiKey: string;
+  apiSecret: string;
+  apiUrl: string;
+  customHeaders?: Record<string, string>;
+  onUnauthenticated: () => void;
+};
+
 export const createRequestGraphql =
-  ({
-    apiKey,
-    apiSecret,
-    apiUrl,
-    onUnauthenticated,
-  }: {
-    apiKey: string;
-    apiSecret: string;
-    apiUrl: string;
-    onUnauthenticated: () => void;
-  }): SdkRequestGraphql =>
+  ({ apiKey, apiSecret, apiUrl, customHeaders, onUnauthenticated }: CreateRequestGraphqlProps): SdkRequestGraphql =>
   ({ query, variables, path = '' }) => {
     // currently, we have 3 graphql endpoints:
     // origin api url has public and acc
@@ -102,6 +100,7 @@ export const createRequestGraphql =
       apiSecret,
       body,
       accessToken: getAccessToken(),
+      customHeaders,
     });
 
     return new Promise((resolve, reject) => {
diff --git a/packages/core/src/utils/sdkFetch.ts b/packages/core/src/utils/sdkFetch.ts
index 53a0402..b9d6be7 100644
--- a/packages/core/src/utils/sdkFetch.ts
+++ b/packages/core/src/utils/sdkFetch.ts
@@ -32,8 +32,15 @@ export interface SdkFetch {
   (path: string, init: RequestInit): Promise<Response>;
 }
 
+type CreateFetchProps = {
+  apiKey: string;
+  apiSecret: string;
+  apiUrl: string;
+  customHeaders?: Record<string, string>;
+};
+
 export const createFetch =
-  ({ apiKey, apiSecret, apiUrl }: { apiKey: string; apiSecret: string; apiUrl: string }): SdkFetch =>
+  ({ apiKey, apiSecret, apiUrl, customHeaders }: CreateFetchProps): SdkFetch =>
   async (path, init) => {
     const serviceUri = `${apiUrl}/${path}`;
 
@@ -44,6 +51,7 @@ export const createFetch =
       apiKey,
       apiSecret,
       accessToken: getAccessToken(),
+      customHeaders,
     });
 
     const { headers: initHeaders, ...restInit } = init;
@@ -51,8 +59,8 @@ export const createFetch =
     const response = await crossFetch(serviceUri, {
       headers: {
         'Content-Type': 'application/x-www-form-urlencoded',
-        ...serviceHeaders,
         ...initHeaders,
+        ...serviceHeaders,
       },
       credentials: 'include',
       ...restInit,
diff --git a/packages/core/src/utils/serviceHeaderBuilder.ts b/packages/core/src/utils/serviceHeaderBuilder.ts
index 193caa0..53b96ac 100644
--- a/packages/core/src/utils/serviceHeaderBuilder.ts
+++ b/packages/core/src/utils/serviceHeaderBuilder.ts
@@ -8,6 +8,7 @@ type BuilderInput = {
   apiSecret: string;
   body?: BodyInit | null;
   accessToken?: string | null;
+  customHeaders?: Record<string, string>;
 };
 
 const serviceHeaderBuilder = ({
@@ -17,6 +18,7 @@ const serviceHeaderBuilder = ({
   apiKey,
   body = '',
   accessToken,
+  customHeaders = {},
 }: BuilderInput): HeadersInit => {
   if (!apiKey || !apiSecret) {
     return {};
@@ -38,6 +40,7 @@ const serviceHeaderBuilder = ({
       'Access-Control-Allow-Credentials': 'true',
       Authorization: `Bearer ${accessToken}`,
     }),
+    ...customHeaders,
   };
 };