fix(minimax): attach MINIMAX_API_KEY on anthropic messages requests

litellm/llms/minimax/messages/transformation.py

@@ -2,7 +2,7 @@
 MiniMax Anthropic transformation config - extends AnthropicConfig for MiniMax's Anthropic-compatible API
 """
 
-from typing import Final
+from typing import Any, Final  # noqa: TID251  # override below must mirror the legacy base signature
 
 import litellm
 from litellm.llms.anthropic.experimental_pass_through.messages.transformation import (
@@ -49,6 +49,26 @@ class MinimaxMessagesConfig(AnthropicMessagesConfig):
         """
         return api_base or get_secret_str("MINIMAX_API_BASE") or "https://api.minimax.io/anthropic/v1/messages"
 
+    def validate_anthropic_messages_environment(
+        self,
+        headers: dict,  # mutable-ok: mirrors the legacy base override signature
+        model: str,
+        messages: list[Any],  # mutable-ok: mirrors the legacy base override signature
+        optional_params: dict,  # mutable-ok: mirrors the legacy base override signature
+        litellm_params: dict,  # mutable-ok: mirrors the legacy base override signature
+        api_key: str | None = None,
+        api_base: str | None = None,
+    ) -> tuple[dict, str | None]:  # mutable-ok: mirrors the legacy base override signature
+        return super().validate_anthropic_messages_environment(
+            headers=headers,
+            model=model,
+            messages=messages,
+            optional_params=optional_params,
+            litellm_params=litellm_params,
+            api_key=self.get_api_key(api_key=api_key),
+            api_base=api_base,
+        )
+
     def get_complete_url(
         self,
         api_base: str | None,

tests/test_litellm/llms/minimax/messages/test_transformation.py

@@ -142,3 +142,33 @@ if __name__ == "__main__":
     print("✓ Provider config manager test passed")
 
     print("\n✅ All basic tests passed!")
+
+
+def test_minimax_messages_env_key_attached(monkeypatch):
+    """Regression: an env-only MINIMAX_API_KEY must be attached on /v1/messages validation"""
+    monkeypatch.setenv("MINIMAX_API_KEY", "test-minimax-env-key")
+    monkeypatch.delenv("ANTHROPIC_API_KEY", raising=False)
+    monkeypatch.delenv("ANTHROPIC_AUTH_TOKEN", raising=False)
+    config = MinimaxMessagesConfig()
+    headers, _ = config.validate_anthropic_messages_environment(
+        headers={},
+        model="MiniMax-M2.1",
+        messages=[{"role": "user", "content": "hi"}],
+        optional_params={},
+        litellm_params={},
+    )
+    assert headers["x-api-key"] == "test-minimax-env-key"
+
+
+def test_minimax_messages_explicit_key_wins_over_env(monkeypatch):
+    monkeypatch.setenv("MINIMAX_API_KEY", "env-key")
+    config = MinimaxMessagesConfig()
+    headers, _ = config.validate_anthropic_messages_environment(
+        headers={},
+        model="MiniMax-M2.1",
+        messages=[{"role": "user", "content": "hi"}],
+        optional_params={},
+        litellm_params={},
+        api_key="param-key",
+    )
+    assert headers["x-api-key"] == "param-key"