diff --git a/cobo_custody/client/client.py b/cobo_custody/client/client.py
index 360e725..ab5408b 100644
--- a/cobo_custody/client/client.py
+++ b/cobo_custody/client/client.py
@@ -279,4 +279,7 @@ def get_staking_history(self) -> ApiResponse:
         return self.request("GET", "/v1/custody/staking_history/", {})
 
     def get_gas_station_balance(self) -> ApiResponse:
-        return self.request("GET", "/v1/custody/get_gas_station_balance/", {})
\ No newline at end of file
+        return self.request("GET", "/v1/custody/get_gas_station_balance/", {})
+
+    def add_coin(self, coin: str) -> ApiResponse:
+        return self.request("POST", "/v1/custody/add_coin/", {"coin": coin})
\ No newline at end of file