diff --git a/services/common/src/mcp_common/environment.py b/services/common/src/mcp_common/environment.py
index d09d014..2a2dcee 100644
--- a/services/common/src/mcp_common/environment.py
+++ b/services/common/src/mcp_common/environment.py
@@ -29,13 +29,18 @@ def resolve_environment(
     env_var: str,
     flag_key: str,
     exchange: str,
+    default_base_url_live: str | None = None,
+    default_base_url_testnet: str | None = None,
 ) -> EnvironmentInfo:
     """Risolvi l'ambiente per un MCP exchange.
 
-    creds: dict letto dal secret JSON. Deve contenere base_url_live e base_url_testnet.
+    creds: dict letto dal secret JSON. Può contenere base_url_live/base_url_testnet
+        per override; in assenza vengono usati i default kwargs.
     env_var: nome della env var di override (es. DERIBIT_TESTNET).
     flag_key: chiave booleana nel secret JSON (es. "testnet" o "paper" per alpaca).
     exchange: nome exchange per logging/info.
+    default_base_url_live / default_base_url_testnet: URL canonici dell'exchange,
+        applicati se non presenti in creds.
     """
     env_value = os.environ.get(env_var)
     if env_value is not None:
@@ -49,6 +54,11 @@ def resolve_environment(
         environment = "testnet"
         source = "default"
 
+    if default_base_url_live is not None:
+        creds.setdefault("base_url_live", default_base_url_live)
+    if default_base_url_testnet is not None:
+        creds.setdefault("base_url_testnet", default_base_url_testnet)
+
     base_url = creds["base_url_testnet"] if environment == "testnet" else creds["base_url_live"]
     return EnvironmentInfo(
         exchange=exchange,
diff --git a/services/common/tests/test_environment.py b/services/common/tests/test_environment.py
index e7defb0..a142592 100644
--- a/services/common/tests/test_environment.py
+++ b/services/common/tests/test_environment.py
@@ -74,6 +74,37 @@ def test_env_value_truthy_parsing(monkeypatch, raw, expected):
     assert info.environment == expected
 
 
+def test_default_base_urls_applied_when_creds_missing(monkeypatch):
+    monkeypatch.delenv("X_TESTNET", raising=False)
+    creds: dict = {}
+    info = resolve_environment(
+        creds,
+        env_var="X_TESTNET",
+        flag_key="testnet",
+        exchange="x",
+        default_base_url_live="https://live.example",
+        default_base_url_testnet="https://test.example",
+    )
+    assert info.base_url == "https://test.example"
+    assert creds["base_url_live"] == "https://live.example"
+    assert creds["base_url_testnet"] == "https://test.example"
+
+
+def test_creds_base_urls_override_defaults(monkeypatch):
+    monkeypatch.delenv("X_TESTNET", raising=False)
+    creds = {"base_url_live": "L", "base_url_testnet": "T"}
+    info = resolve_environment(
+        creds,
+        env_var="X_TESTNET",
+        flag_key="testnet",
+        exchange="x",
+        default_base_url_live="https://live.example",
+        default_base_url_testnet="https://test.example",
+    )
+    assert info.base_url == "T"
+    assert creds["base_url_live"] == "L"
+
+
 def test_alpaca_paper_flag_key(monkeypatch):
     """Alpaca usa 'paper' invece di 'testnet' nel secret."""
     monkeypatch.delenv("ALPACA_PAPER", raising=False)
diff --git a/services/mcp-alpaca/src/mcp_alpaca/__main__.py b/services/mcp-alpaca/src/mcp_alpaca/__main__.py
index e04eb28..5ad5794 100644
--- a/services/mcp-alpaca/src/mcp_alpaca/__main__.py
+++ b/services/mcp-alpaca/src/mcp_alpaca/__main__.py
@@ -20,14 +20,13 @@ def main():
     with open(creds_file) as f:
         creds = json.load(f)
 
-    creds.setdefault("base_url_live", "https://api.alpaca.markets")
-    creds.setdefault("base_url_testnet", "https://paper-api.alpaca.markets")
-
     env_info = resolve_environment(
         creds,
         env_var="ALPACA_PAPER",
         flag_key="paper",
         exchange="alpaca",
+        default_base_url_live="https://api.alpaca.markets",
+        default_base_url_testnet="https://paper-api.alpaca.markets",
     )
 
     client = AlpacaClient(
diff --git a/services/mcp-bybit/src/mcp_bybit/__main__.py b/services/mcp-bybit/src/mcp_bybit/__main__.py
index b821c4f..e28c8b7 100644
--- a/services/mcp-bybit/src/mcp_bybit/__main__.py
+++ b/services/mcp-bybit/src/mcp_bybit/__main__.py
@@ -20,14 +20,13 @@ def main():
     with open(creds_file) as f:
         creds = json.load(f)
 
-    creds.setdefault("base_url_live", "https://api.bybit.com")
-    creds.setdefault("base_url_testnet", "https://api-testnet.bybit.com")
-
     env_info = resolve_environment(
         creds,
         env_var="BYBIT_TESTNET",
         flag_key="testnet",
         exchange="bybit",
+        default_base_url_live="https://api.bybit.com",
+        default_base_url_testnet="https://api-testnet.bybit.com",
     )
 
     client = BybitClient(
diff --git a/services/mcp-deribit/src/mcp_deribit/__main__.py b/services/mcp-deribit/src/mcp_deribit/__main__.py
index 81b2870..3471c02 100644
--- a/services/mcp-deribit/src/mcp_deribit/__main__.py
+++ b/services/mcp-deribit/src/mcp_deribit/__main__.py
@@ -27,15 +27,13 @@ def main():
     with open(creds_file) as f:
         creds = json.load(f)
 
-    # Default base URLs per backward-compat con secret schema legacy
-    creds.setdefault("base_url_live", "https://www.deribit.com/api/v2")
-    creds.setdefault("base_url_testnet", "https://test.deribit.com/api/v2")
-
     env_info = resolve_environment(
         creds,
         env_var="DERIBIT_TESTNET",
         flag_key="testnet",
         exchange="deribit",
+        default_base_url_live="https://www.deribit.com/api/v2",
+        default_base_url_testnet="https://test.deribit.com/api/v2",
     )
 
     client = DeribitClient(
diff --git a/services/mcp-hyperliquid/src/mcp_hyperliquid/__main__.py b/services/mcp-hyperliquid/src/mcp_hyperliquid/__main__.py
index 0d623ad..512dc58 100644
--- a/services/mcp-hyperliquid/src/mcp_hyperliquid/__main__.py
+++ b/services/mcp-hyperliquid/src/mcp_hyperliquid/__main__.py
@@ -19,14 +19,13 @@ def main():
     with open(wallet_file) as f:
         creds = json.load(f)
 
-    creds.setdefault("base_url_live", "https://api.hyperliquid.xyz")
-    creds.setdefault("base_url_testnet", "https://api.hyperliquid-testnet.xyz")
-
     env_info = resolve_environment(
         creds,
         env_var="HYPERLIQUID_TESTNET",
         flag_key="testnet",
         exchange="hyperliquid",
+        default_base_url_live="https://api.hyperliquid.xyz",
+        default_base_url_testnet="https://api.hyperliquid-testnet.xyz",
     )
 
     client = HyperliquidClient(