diff --git a/pbc_client/__init__.py b/pbc_client/__init__.py
index 2a4c706..4640d6b 100644
--- a/pbc_client/__init__.py
+++ b/pbc_client/__init__.py
@@ -13,11 +13,8 @@ from frozendict import frozendict
 logger = logging.getLogger(__name__)
 
 
-# mainnet: https://reader.partisiablockchain.com
-# testnet: https://node1.testnet.partisiablockchain.com
-
-
-HOSTNAME = 'reader.partisiablockchain.com'
+HOSTNAME_MAINNET = 'reader.partisiablockchain.com'
+HOSTNAME_TESTNET = 'node1.testnet.partisiablockchain.com'
 
 URL_ACCOUNT_PLUGIN = 'https://{hostname}/{shard}blockchain/accountPlugin/local'
 URL_ACCOUNT_PLUGIN_GLOBAL = 'https://{hostname}/{shard}blockchain/accountPlugin/global'
@@ -49,6 +46,7 @@ class Balances:
 @dataclasses.dataclass(frozen=True)
 class PbcClient:
     session: requests.Session
+    hostname: str = HOSTNAME_MAINNET
 
     def get_json(
         self,
@@ -82,7 +80,7 @@ class PbcClient:
         data: dict = {'path': []}
 
         url: str = URL_ACCOUNT_PLUGIN_GLOBAL.format(
-            hostname=HOSTNAME,
+            hostname=self.hostname,
             shard='',
         )
 
@@ -93,7 +91,7 @@ class PbcClient:
         coins = self.determine_coins()
 
         url = URL_ACCOUNT_PLUGIN.format(
-            hostname=HOSTNAME,
+            hostname=self.hostname,
             shard=shard_id_for_address(address),
         )
 
@@ -120,10 +118,9 @@ class PbcClient:
 
     def get_contract_state(self, address: str) -> tuple[dict, datetime.datetime]:
         url = URL_CONTRACT_STATE.format(
-            hostname=HOSTNAME,
+            hostname=self.hostname,
             shard=shard_id_for_address(address),
             address=address,
         )
         data: dict = {'path': []}
         return self.get_json(url, data=data)
-