diff --git a/python/packages/mistral/agent_framework_mistral/_chat_client.py b/python/packages/mistral/agent_framework_mistral/_chat_client.py
index b97fb8f072d..d70b6a61f13 100644
--- a/python/packages/mistral/agent_framework_mistral/_chat_client.py
+++ b/python/packages/mistral/agent_framework_mistral/_chat_client.py
@@ -357,7 +357,7 @@ def __init__(
                 Can also be set via environment variable ``MISTRAL_CHAT_MODEL``.
             api_key: Mistral API key. Defaults to ``MISTRAL_API_KEY`` environment variable.
             server_url: Optional server URL override. Defaults to ``MISTRAL_SERVER_URL``
-                environment variable, or the Mistral default.
+                environment variable, or the Mistral default. Ignored when a Mistral SDK ``client`` is provided.
             client: Optional pre-configured ``mistralai.client.Mistral``.
             http_client: Optional pre-configured ``httpx.AsyncClient``. When provided, api_key
                 is not required and the client is expected to carry its own auth headers.
@@ -383,6 +383,8 @@ def __init__(
         if client is not None and http_client is not None:
             raise ValueError("Provide either 'client' or 'http_client', not both.")
 
+        # An injected SDK client owns its credentials and endpoint, so api_key and server_url are not required
+        # and their loaded values are ignored below.
         mistral_settings = load_settings(
             MistralSettings,
             env_prefix="MISTRAL_",
@@ -401,8 +403,8 @@ def __init__(
 
         if isinstance(client, Mistral):
             self.client = client
-            if self.server_url is None:
-                self.server_url = client.sdk_configuration.get_server_details()[0]
+            # The injected SDK client sends the requests, so its endpoint wins over configured settings.
+            self.server_url = client.sdk_configuration.get_server_details()[0]
         else:
             client_kwargs: dict[str, Any] = {"timeout_ms": _DEFAULT_TIMEOUT_MS}
             if resolved_api_key := mistral_settings.get("api_key"):
@@ -990,7 +992,7 @@ def __init__(
                 Can also be set via environment variable ``MISTRAL_CHAT_MODEL``.
             api_key: Mistral API key. Defaults to ``MISTRAL_API_KEY`` environment variable.
             server_url: Optional server URL override. Defaults to ``MISTRAL_SERVER_URL``
-                environment variable, or the Mistral default.
+                environment variable, or the Mistral default. Ignored when a Mistral SDK ``client`` is provided.
             client: Optional pre-configured ``mistralai.client.Mistral``.
             http_client: Optional pre-configured ``httpx.AsyncClient``. When provided, api_key
                 is not required and the client is expected to carry its own auth headers.
diff --git a/python/packages/mistral/agent_framework_mistral/_embedding_client.py b/python/packages/mistral/agent_framework_mistral/_embedding_client.py
index 29b0107c22e..a097bc3c58a 100644
--- a/python/packages/mistral/agent_framework_mistral/_embedding_client.py
+++ b/python/packages/mistral/agent_framework_mistral/_embedding_client.py
@@ -96,7 +96,7 @@ class RawMistralEmbeddingClient(
             Can also be set via environment variable ``MISTRAL_EMBEDDING_MODEL``.
         api_key: Mistral API key. Defaults to ``MISTRAL_API_KEY`` environment variable.
         server_url: Optional server URL override. Defaults to ``MISTRAL_SERVER_URL``
-            environment variable, or the Mistral default.
+            environment variable, or the Mistral default. Ignored when a Mistral SDK ``client`` is provided.
         http_client: Optional pre-configured ``httpx.AsyncClient``. When provided, api_key is
             not required and the client is expected to carry its own auth headers and base URL.
         client: Optional pre-configured ``mistralai.client.Mistral``. Passing an HTTP client via
@@ -138,6 +138,8 @@ def __init__(
         if client is not None and http_client is not None:
             raise ValueError("Provide either 'client' or 'http_client', not both.")
 
+        # An injected SDK client owns its credentials and endpoint, so api_key and server_url are not required
+        # and their loaded values are ignored below.
         injected = client is not None or http_client is not None
         required_fields = ["embedding_model"] if injected else ["embedding_model", "api_key"]
         mistral_settings = load_settings(
@@ -157,8 +159,8 @@ def __init__(
 
         if isinstance(client, Mistral):
             self.client = client
-            if self.server_url is None:
-                self.server_url = client.sdk_configuration.get_server_details()[0]
+            # The injected SDK client sends the requests, so its endpoint wins over configured settings.
+            self.server_url = client.sdk_configuration.get_server_details()[0]
         else:
             client_kwargs: dict[str, Any] = {"timeout_ms": _DEFAULT_TIMEOUT_MS}
             if resolved_api_key := mistral_settings.get("api_key"):
@@ -293,7 +295,7 @@ class MistralEmbeddingClient(
             Can also be set via environment variable ``MISTRAL_EMBEDDING_MODEL``.
         api_key: Mistral API key. Defaults to ``MISTRAL_API_KEY`` environment variable.
         server_url: Optional server URL override. Defaults to ``MISTRAL_SERVER_URL``
-            environment variable, or the Mistral default.
+            environment variable, or the Mistral default. Ignored when a Mistral SDK ``client`` is provided.
         http_client: Optional pre-configured ``httpx.AsyncClient``.
         client: Optional pre-configured ``mistralai.client.Mistral``. Passing an HTTP client via
             this parameter remains supported but is deprecated; use ``http_client`` instead.
diff --git a/python/packages/mistral/tests/mistral/test_mistral_chat_client.py b/python/packages/mistral/tests/mistral/test_mistral_chat_client.py
index 9430f61bb01..80da9f619ce 100644
--- a/python/packages/mistral/tests/mistral/test_mistral_chat_client.py
+++ b/python/packages/mistral/tests/mistral/test_mistral_chat_client.py
@@ -533,6 +533,23 @@ async def test_get_response_rejects_transport_arguments_split_across_options_and
         await client.close()
 
 
+@pytest.mark.parametrize("client_type", [RawMistralChatClient, MistralChatClient])
+@pytest.mark.parametrize("server_url", [None, "https://explicit.example"], ids=["env", "explicit"])
+def test_injected_sdk_client_endpoint_wins_over_configured_server_url(
+    client_type: type[RawMistralChatClient],
+    server_url: str | None,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """An injected SDK client defines the endpoint, so MISTRAL_SERVER_URL or server_url should not change it."""
+    monkeypatch.setenv("MISTRAL_SERVER_URL", "https://env.example")
+    sdk_client = Mistral(api_key="test-key", server_url="https://client.example")
+
+    client = client_type(model="mistral-small-latest", client=sdk_client, server_url=server_url)
+
+    assert client.service_url() == "https://client.example"
+    assert client.client is sdk_client
+
+
 @pytest.mark.parametrize("client_type", [RawMistralChatClient, MistralChatClient])
 @pytest.mark.parametrize("stream", [False, True])
 @pytest.mark.parametrize("configuration", ["server_url", "http_client", "sdk"])
diff --git a/python/packages/mistral/tests/mistral/test_mistral_embedding_client.py b/python/packages/mistral/tests/mistral/test_mistral_embedding_client.py
index eb6851e803b..8471d10e39c 100644
--- a/python/packages/mistral/tests/mistral/test_mistral_embedding_client.py
+++ b/python/packages/mistral/tests/mistral/test_mistral_embedding_client.py
@@ -211,6 +211,21 @@ def test_mistral_embedding_service_url_custom() -> None:
     assert client.service_url() == "https://custom.mistral.ai"
 
 
+@pytest.mark.parametrize("server_url", [None, "https://explicit.example"], ids=["env", "explicit"])
+def test_mistral_embedding_injected_sdk_client_endpoint_wins_over_configured_server_url(
+    server_url: str | None,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """An injected SDK client defines the endpoint, so MISTRAL_SERVER_URL or server_url should not change it."""
+    monkeypatch.setenv("MISTRAL_SERVER_URL", "https://env.example")
+    sdk_client = Mistral(api_key="test-key", server_url="https://client.example")
+
+    client = MistralEmbeddingClient(model="mistral-embed", client=sdk_client, server_url=server_url)
+
+    assert client.service_url() == "https://client.example"
+    assert client.client is sdk_client
+
+
 async def test_mistral_embedding_close_only_closes_owned_client() -> None:
     owned = MistralEmbeddingClient(model="mistral-embed", api_key="test-key")
     owned_http_client = owned.client.sdk_configuration.async_client