diff --git a/readme.md b/readme.md
index f5aef83..df47b76 100644
--- a/readme.md
+++ b/readme.md
@@ -24,19 +24,39 @@ In order to use our API, you will need to :
 Visite [our website ](https://slick-pay.com/) and create an account. If you are merchant you have to add your satim information like username and password
 #### 2. Get api's key
 After logging in, from your dashboard, you will able to get your PUBLIC_KEY.
-#### 3. Configure through environment variables
+#### 3. Configure API Client
+```python
+from slickpay import slickPayApi
+
+env = "dev"
+api_client = slickPayApi()
+api_client.config(environment=env, public_key="PUBLIC_KEY")
+```
+#### 4. Configure through environment variables
 Create a .env file and inside your .env file create a variable like this:
 ```python
   public_key= your_public_key
-  sandbox= True or False
 ```
+Import environment variables
+```python
+import os
+from dotenv import load_dotenv
+load_dotenv()
+
+from slickpay import slickPayApi
+
+env = "prod"
+api_client = slickPayApi()
+api_client.config(environment=env, public_key=os.environ["public_key"])
+```
+
 # How to use?
 ## Concerning merchant account
 ## InvoiceTransferMerchant
 ### Create Invoice
 ```python
 from slickpay import InvoiceTransferMerchant
-    invoiceMerchant = InvoiceTransferMerchant()
+    invoiceMerchant = InvoiceTransferMerchant(client=api_client)
     data = 
     {
         'amount': 10000,
@@ -80,7 +100,7 @@ from slickpay import InvoiceTransferMerchant
 ### Create
 ```python
 from slickpay import Account
-    userAccount = Account()
+    userAccount = Account(client=api_client)
     data = {
         "title"    : "Lorem Ipsum",
         "lastname" : "Lorem",
@@ -115,7 +135,7 @@ from slickpay import Account
 ### Create Contact
 ```python
 from slickpay import Contact
-    userContact = Contact()
+    userContact = Contact(client=api_client)
     data = {
         "title"    : "Lorem Ipsum",
         "lastname" : "Lorem",
@@ -151,7 +171,7 @@ from slickpay import Contact
 ### Calculate Commission
 ```python
 from slickpay import Transfer
-    userTransfer = Transfer()
+    userTransfer = Transfer(client=api_client)
     res=userTransfer.calculateCommission(amount)
     return res
 ```
@@ -189,7 +209,7 @@ from slickpay import Transfer
 ### Calculate Commission
 ```python
 from slickpay import PaymentAggregation
-    userPaymentAggregation = PaymentAggregation()
+    userPaymentAggregation = PaymentAggregation(client=api_client)
     data = {
         "type": "percentage",
         "total": 10000,
@@ -266,7 +286,7 @@ from slickpay import PaymentAggregation
 ### Calculate Commission
 ```python
 from slickpay import InvoiceTransfer
-    userInvoiceTransfer = InvoiceTransfer()
+    userInvoiceTransfer = InvoiceTransfer(client=api_client)
     res=userInvoiceTransfer.calculateCommissionInvoice(amount)
     return res
 ```
@@ -314,4 +334,4 @@ from slickpay import InvoiceTransfer
 ```
 # More help
 - [Slick-Pay website](https://slick-pay.com/)
-- [devapi-slick-pay](https://www.devapi.slick-pay.com/)
\ No newline at end of file
+- [devapi-slick-pay](https://www.devapi.slick-pay.com/)
diff --git a/setup.py b/setup.py
index 3a78285..00e2c75 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@
 setup(
     name='slick-pay',
     packages=['slick-pay'],  # Chose the same as "name"
-    version='0.3',  # Start with a small number and increase it with every change you make
+    version='0.4',  # Start with a small number and increase it with every change you make
     license='MIT',  # Chose a license from here: https://help.github.com/articles/licensing-a-repository
     description='slick-pay Gateway (Python Library)',  # Give a short description about your library
     author='Rahim',  # Type in your name
diff --git a/slickpay/__init__.py b/slickpay/__init__.py
index 295a337..adcbb93 100644
--- a/slickpay/__init__.py
+++ b/slickpay/__init__.py
@@ -4,4 +4,4 @@
 from slickpay.user import Transfer
 from slickpay.user import PaymentAggregation
 from slickpay.user import InvoiceTransfer
-
+from slickpay.client import SlickPayApi
diff --git a/slickpay/client.py b/slickpay/client.py
new file mode 100644
index 0000000..2a9dd8b
--- /dev/null
+++ b/slickpay/client.py
@@ -0,0 +1,58 @@
+import requests
+
+API_VERSION = "v2"
+DEV_API_URL = "https://www.devapi.slick-pay.com/api/"
+PROD_API_URL = "https://www.prodapi.slick-pay.com/api/"
+
+
+class SlickPayApi:
+    def __init__(self) -> None:
+        self.api_version = API_VERSION
+        self._config = {}
+
+    def config(self, environment, public_key):
+        if environment in ["dev", "prod"]:
+            self._config["public_key"] = public_key
+
+        if environment == "dev":
+            self._config["base_url"] = DEV_API_URL
+
+        if environment == "prod":
+            self._config["base_url"] = PROD_API_URL
+        
+        return self._config
+
+    def build_request_url(self, url_path):
+        return f'{self._config["base_url"]}{self.api_version}/{url_path}'
+
+    @property
+    def headers(self):
+        if self._config:
+            return {
+                "Authorization": f'Bearer {self._config["public_key"]}',
+                "Accept": "application/json",
+            }
+    
+    def post(self, url_path, data):
+        request_url = self.build_request_url(url_path=url_path)
+        if self.headers:
+            response = requests.post(url=request_url, headers=self.headers, json=data)
+            return response.json()
+
+    def get(self, url_path):
+        request_url = self.build_request_url(url_path=url_path)
+        if self.headers:
+            response = requests.get(url=request_url, headers=self.headers)
+            return response.json()
+
+    def put(self, url_path, data):
+        request_url = self.build_request_url(url_path=url_path)
+        if self.headers:
+            response = requests.put(url=request_url, headers=self.headers, json=data)
+            return response.json()
+
+    def delete(self, url_path):
+        request_url = self.build_request_url(url_path=url_path)
+        if self.headers:
+            response = requests.delete(url=request_url, headers=self.headers)
+            return response.json()
diff --git a/slickpay/merchant.py b/slickpay/merchant.py
index 17b6363..11bfa5b 100644
--- a/slickpay/merchant.py
+++ b/slickpay/merchant.py
@@ -1,64 +1,28 @@
-import os
-
-import requests
-from dotenv import load_dotenv
-
-load_dotenv()
-
-
 class InvoiceTransferMerchant:
+    def __init__(self, client) -> None:
+        self.client = client
 
     def createInvoice(self, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/merchants/invoices'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/merchants/invoices'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.post(url, headers=headers, json=data)
-        body = res.json()
-        return body
+        url = "merchants/invoices"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
     def invoiceDetail(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/merchants/invoices/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/merchants/invoices/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"invoices/{int(uid)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def listInvoice(self, offset, page):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/merchants/invoices?offset={int(offset)}&page={int(page)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/merchants/invoices?offset={int(offset)}&page={int(page)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"merchants/invoices?offset={int(offset)}&page={int(page)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def updateInvoice(self, data, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/merchants/invoices/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/merchants/invoices/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.put(url, headers=headers, json=data)
-
-        return res.json()
+        url = f"merchants/invoices/{int(uid)}"
+        response = self.client.put(url_path=url, data=data)
+        return response
 
     def deleteInvoice(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/merchants/invoices/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/merchants/invoices/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.delete(url, headers=headers)
-
-        return res.json()
+        url = f"merchants/invoices/{int(uid)}"
+        response = self.client.delete(url_path=url)
+        return response
diff --git a/slickpay/user.py b/slickpay/user.py
index 7c3cb6a..f6b7bce 100644
--- a/slickpay/user.py
+++ b/slickpay/user.py
@@ -1,340 +1,164 @@
-import os
-
-import requests
-
-from dotenv import load_dotenv
-
-load_dotenv()
-
-
 class Account:
+    def __init__(self, client) -> None:
+        self.client = client
 
     def create(self, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/accounts'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/accounts'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.post(url, headers=headers, data=data)
-        body = res.json()
-        return body
+        url = "users/accounts"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
     def update(self, uid, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/accounts/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/accounts/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-
-        res = requests.put(url, headers=headers, json=data)
-
-        return res.json()
+        url = f"users/accounts/{int(uid)}"
+        response = self.client.put(url_path=url, data=data)
+        return response
 
     def list(self, offset, page):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/accounts?offset={int(offset)}&page={int(page)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/accounts?offset={int(offset)}&page={int(page)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/accounts?offset={int(offset)}&page={int(page)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def accountDetails(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/accounts/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/accounts/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/accounts/{int(uid)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def delete(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/accounts/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/accounts/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.delete(url, headers=headers)
-
-        return res.json()
+        url = f"users/accounts/{int(uid)}"
+        response = self.client.delete(url_path=url)
+        return response
 
 
 class Contact:
+    def __init__(self, client) -> None:
+        self.client = client
 
     def createContact(self, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/contacts'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/contacts'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.post(url, headers=headers, json=data)
-        body = res.json()
-        return body
+        url = "users/contacts"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
     def contactDetail(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/contacts/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/contacts/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/contacts/{int(uid)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def listContact(self, offset, page):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/contacts?offset={int(offset)}&page={int(page)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/contacts?offset={int(offset)}&page={int(page)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/contacts?offset={int(offset)}&page={int(page)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def updateContact(self, data, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/contacts/'+str(uid)
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/contacts/'+str(uid)
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.put(url, headers=headers, data=data)
-
-        return res.json()
+        url = f"users/contacts/{str(uid)}"
+        response = self.client.put(url_path=url, data=data)
+        return response
 
     def deleteContact(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/contacts/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/contacts/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.delete(url, headers=headers)
-
-        return res.json()
+        url = f"users/contacts/{int(uid)}"
+        response = self.client.delete(url_path=url)
+        return response
 
 
 class Transfer:
+    def __init__(self, client) -> None:
+        self.client = client
 
     def calculateCommission(self, amount):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/transfers/commission'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/transfers/commission'
-
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        data = {
-            'amount': amount
-        }
-        res = requests.post(url, headers=headers, data=data)
-        return res.json()
+        url = "users/transfers/commission"
+        response = self.client.post(url_path=url, data=amount)
+        return response
 
     def createPayment(self, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/transfers'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/transfers'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.post(url, headers=headers, json=data)
-        # print(res)
-        body = res.json()
-        return body
-        # return res
+        url = "users/transfers"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
-    def paymentDetail(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/transfers/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/transfers/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
 
-        return res.json()
+    def paymentDetail(self, uid):
+        url = f"users/transfers/{int(uid)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def listTransfer(self, offset, page):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/transfers?offset={int(offset)}&page={int(page)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/transfers?offset={int(offset)}&page={int(page)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/transfers?offset={int(offset)}&page={int(page)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def updateTransfer(self, data, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/transfers/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/transfers/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.put(url, headers=headers, json=data)
-
-        return res.json()
+        url = f"users/transfers/{int(uid)}"
+        response = self.client.put(url_path=url, data=data)
+        return response
 
     def deleteTransfer(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/transfers/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/transfers/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.delete(url, headers=headers)
-
-        return res.json()
+        url = f"users/transfers/{int(uid)}"
+        response = self.client.delete(url_path=url)
+        return response
 
 
 class PaymentAggregation:
+    def __init__(self, client) -> None:
+        self.client = client
 
     def commission(self, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/aggregations/commission'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/aggregations/commission'
-
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-
-        res = requests.post(url, headers=headers, json=data)
-        return res.json()
+        url = "users/aggregations/commission"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
     def create(self, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/aggregations'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/aggregations'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.post(url, headers=headers, json=data)
-        body = res.json()
-        return body
+        url = "users/aggregations"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
     def details(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/aggregations/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/aggregations/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/aggregations/{int(uid)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def list(self, offset, page):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/aggregations?offset={int(offset)}&page={int(page)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/aggregations?offset={int(offset)}&page={int(page)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/aggregations?offset={int(offset)}&page={int(page)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def update(self, data, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/aggregations/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/aggregations/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.put(url, headers=headers, json=data)
-        body = res.json()
-        return body
+        url = f"users/aggregations/{int(uid)}"
+        response = self.client.put(url_path=url, data=data)
+        return response
 
     def delete(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/aggregations/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/aggregations/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.delete(url, headers=headers)
-        body = res.json()
-        return body
+        url = f"users/aggregations/{int(uid)}"
+        response = self.client.delete(url_path=url)
+        return response
 
 
 class InvoiceTransfer:
+    def __init__(self, client) -> None:
+        self.client = client
 
     def calculateCommissionInvoice(self, amount):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/invoices/commission'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/invoices/commission'
-
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        data = {
-            'amount': amount
-        }
-        res = requests.post(url, headers=headers, data=data)
-        return res.json()
+        url = "users/invoices/commission"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
     def createInvoice(self, data):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/invoices'
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/invoices'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.post(url, headers=headers, json=data)
-        body = res.json()
-        return body
+        url = "users/invoices"
+        response = self.client.post(url_path=url, data=data)
+        return response
 
     def InvoiceDetail(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/invoices/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/invoices/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/invoices/{int(uid)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def listInvoice(self, offset, page):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/invoices?offset={int(offset)}&page={int(page)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/invoices?offset={int(offset)}&page={int(page)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.get(url, headers=headers)
-
-        return res.json()
+        url = f"users/invoices?offset={int(offset)}&page={int(page)}"
+        response = self.client.get(url_path=url)
+        return response
 
     def updateInvoice(self, data, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = 'https://www.devapi.slick-pay.com/api/v2/users/invoices/'+str(uid)
-        else:
-            url = 'https://www.prodapi.slick-pay.com/api/v2/users/invoices/'+str(uid)
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.put(url, headers=headers, json=data)
-
-        return res.json()
+        url = f"users/invoices/{str(uid)}"
+        response = self.client.put(url_path=url, data=data)
+        return response
 
     def deleteInvoice(self, uid):
-        print(self)
-        if os.environ["sandbox"]:
-            url = f'https://www.devapi.slick-pay.com/api/v2/users/invoices/{int(uid)}'
-        else:
-            url = f'https://www.prodapi.slick-pay.com/api/v2/users/invoices/{int(uid)}'
-        headers = {"Authorization": f'{str(os.environ["public_key"])}', "Accept": "application/json"}
-        res = requests.delete(url, headers=headers)
-
-        return res.json()
+        url = f"users/invoices/{int(uid)}"
+        response = self.client.delete(url_path=url)
+        return response