feat(zai): native Anthropic Messages and Responses API passthrough

litellm/llms/zai/messages/__init__.py

@@ -0,0 +1 @@
+

litellm/llms/zai/messages/transformation.py

@@ -0,0 +1,85 @@
+"""
+Z.AI Anthropic-compatible messages transformation config.
+"""
+
+from typing import Any, Final
+
+import litellm
+from litellm.llms.anthropic.experimental_pass_through.messages.transformation import (
+    AnthropicMessagesConfig,
+)
+from litellm.secret_managers.main import get_secret_str
+
+
+class ZAIAnthropicMessagesConfig(AnthropicMessagesConfig):
+    """
+    Z.AI exposes an Anthropic-compatible Messages API at
+    https://api.z.ai/api/anthropic (see
+    https://docs.z.ai/guides/llm/glm-5.3).
+
+    The endpoint accepts the native Anthropic Messages conversation shape
+    and authenticates with the Z.AI API key sent as the Anthropic
+    ``x-api-key`` header.
+    """
+
+    @property
+    def custom_llm_provider(self) -> str | None:
+        return "zai"
+
+    @staticmethod
+    def get_api_key(api_key: str | None = None) -> str | None:
+        return api_key or get_secret_str("ZAI_API_KEY") or litellm.api_key
+
+    @staticmethod
+    def get_api_base(api_base: str | None = None) -> str:
+        return api_base or get_secret_str("ZAI_ANTHROPIC_API_BASE") or "https://api.z.ai/api/anthropic"
+
+    def validate_anthropic_messages_environment(
+        self,
+        headers: dict,
+        model: str,
+        messages: list[Any],
+        optional_params: dict,
+        litellm_params: dict,
+        api_key: str | None = None,
+        api_base: str | None = None,
+    ) -> tuple[dict, str | None]:
+        dynamic_api_key: Final = self.get_api_key(api_key=api_key)
+
+        if "x-api-key" not in headers and "authorization" not in headers and dynamic_api_key is not None:
+            headers["x-api-key"] = dynamic_api_key
+
+        if "anthropic-version" not in headers:
+            headers["anthropic-version"] = "2023-06-01"
+        if "content-type" not in headers:
+            headers["content-type"] = "application/json"
+
+        headers = self._update_headers_with_anthropic_beta(
+            headers=headers,
+            optional_params=optional_params,
+            custom_llm_provider=self.custom_llm_provider or "zai",
+        )
+
+        return headers, api_base
+
+    def get_complete_url(
+        self,
+        api_base: str | None,
+        api_key: str | None,
+        model: str,
+        optional_params: dict,
+        litellm_params: dict,
+        stream: bool | None = None,
+    ) -> str:
+        base_url = self.get_api_base(api_base=api_base).rstrip("/")
+
+        if base_url.endswith("/v1/messages"):
+            return base_url
+        base_url = base_url.removesuffix("/v1/messages")
+        base_url = base_url.removesuffix("/v1")
+        base_url = base_url.removesuffix("/beta")
+
+        if not base_url.endswith("/anthropic") and "/anthropic/" not in base_url:
+            base_url = f"{base_url}/anthropic"
+
+        return f"{base_url}/v1/messages"

litellm/llms/zai/responses/__init__.py

@@ -0,0 +1 @@
+

litellm/llms/zai/responses/transformation.py

@@ -0,0 +1,52 @@
+"""
+Z.AI OpenAI-compatible Responses API transformation config.
+"""
+
+from typing import Final
+
+import litellm
+from litellm.llms.openai.responses.transformation import OpenAIResponsesAPIConfig
+from litellm.secret_managers.main import get_secret_str
+from litellm.types.router import GenericLiteLLMParams
+from litellm.types.utils import LlmProviders
+
+
+class ZAIResponsesAPIConfig(OpenAIResponsesAPIConfig):
+    """
+    Z.AI exposes an OpenAI-compatible Responses API at
+    https://api.z.ai/api/v1 (see https://docs.z.ai/guides/llm/glm-5.3).
+
+    The endpoint authenticates with the Z.AI API key sent as an
+    ``Authorization: Bearer`` header.
+    """
+
+    @property
+    def custom_llm_provider(self) -> LlmProviders:
+        return LlmProviders.ZAI
+
+    def validate_environment(
+        self,
+        headers: dict,
+        model: str,
+        litellm_params: GenericLiteLLMParams | None,
+    ) -> dict:
+        litellm_params = litellm_params or GenericLiteLLMParams()
+
+        api_key: Final = litellm_params.api_key or litellm.api_key or get_secret_str("ZAI_API_KEY")
+
+        headers.setdefault("Content-Type", "application/json")
+        if api_key is not None:
+            headers["Authorization"] = f"Bearer {api_key}"
+        return headers
+
+    def get_complete_url(
+        self,
+        api_base: str | None,
+        litellm_params: dict,
+    ) -> str:
+        base_url = api_base or get_secret_str("ZAI_RESPONSES_API_BASE") or "https://api.z.ai/api/v1"
+
+        base_url = base_url.rstrip("/")
+        if base_url.endswith("/responses"):
+            return base_url
+        return f"{base_url}/responses"

litellm/utils.py

@@ -8482,6 +8482,12 @@ class ProviderConfigManager:
             )
 
             return TencentAnthropicMessagesConfig()
+        elif litellm.LlmProviders.ZAI == provider:
+            from litellm.llms.zai.messages.transformation import (
+                ZAIAnthropicMessagesConfig,
+            )
+
+            return ZAIAnthropicMessagesConfig()
         elif litellm.LlmProviders.GITHUB_COPILOT == provider:
             if "claude" in model_lower:
                 from litellm.llms.github_copilot.messages.transformation import (
@@ -8703,6 +8709,12 @@ class ProviderConfigManager:
             return litellm.BedrockMantleResponsesAPIConfig(
                 use_openai_path=mantle_base_segment(model, litellm.model_cost) == "openai/v1"
             )
+        elif litellm.LlmProviders.ZAI == provider:
+            from litellm.llms.zai.responses.transformation import (
+                ZAIResponsesAPIConfig,
+            )
+
+            return ZAIResponsesAPIConfig()
         return None
 
     @staticmethod

tests/test_litellm/llms/zai/test_zai_anthropic_messages_transformation.py

@@ -0,0 +1,77 @@
+import litellm
+from litellm.llms.anthropic.experimental_pass_through.messages.transformation import (
+    AnthropicMessagesConfig,
+)
+from litellm.llms.zai.messages.transformation import ZAIAnthropicMessagesConfig
+from litellm.utils import ProviderConfigManager
+
+
+def test_zai_provider_uses_anthropic_messages_config():
+    config = ProviderConfigManager.get_provider_anthropic_messages_config(
+        model="glm-5.3",
+        provider=litellm.LlmProviders.ZAI,
+    )
+
+    assert isinstance(config, ZAIAnthropicMessagesConfig)
+    assert config.custom_llm_provider == "zai"
+
+
+def test_anthropic_provider_keeps_default_config_for_zai_named_model():
+    config = ProviderConfigManager.get_provider_anthropic_messages_config(
+        model="glm-5.3",
+        provider=litellm.LlmProviders.ANTHROPIC,
+    )
+
+    assert isinstance(config, AnthropicMessagesConfig)
+    assert not isinstance(config, ZAIAnthropicMessagesConfig)
+
+
+def test_zai_anthropic_messages_config_defaults(monkeypatch):
+    monkeypatch.delenv("ZAI_ANTHROPIC_API_BASE", raising=False)
+    config = ZAIAnthropicMessagesConfig()
+
+    assert config.custom_llm_provider == "zai"
+    assert config.get_api_base() == "https://api.z.ai/api/anthropic"
+
+
+def test_zai_anthropic_messages_url_defaults_to_anthropic_endpoint():
+    config = ZAIAnthropicMessagesConfig()
+
+    url_cases = {
+        None: "https://api.z.ai/api/anthropic/v1/messages",
+        "https://api.z.ai/api/anthropic": "https://api.z.ai/api/anthropic/v1/messages",
+        "https://api.z.ai/api/anthropic/v1": "https://api.z.ai/api/anthropic/v1/messages",
+        "https://api.z.ai/api/anthropic/v1/messages": "https://api.z.ai/api/anthropic/v1/messages",
+        "https://api.z.ai/api": "https://api.z.ai/api/anthropic/v1/messages",
+    }
+
+    for api_base, expected_url in url_cases.items():
+        assert (
+            config.get_complete_url(
+                api_base=api_base,
+                api_key=None,
+                model="glm-5.3",
+                optional_params={},
+                litellm_params={},
+            )
+            == expected_url
+        )
+
+
+def test_zai_anthropic_messages_headers_use_zai_key():
+    config = ZAIAnthropicMessagesConfig()
+
+    headers, api_base = config.validate_anthropic_messages_environment(
+        headers={},
+        model="glm-5.3",
+        messages=[],
+        optional_params={},
+        litellm_params={},
+        api_key="sk-zai",
+        api_base="https://example.test/anthropic",
+    )
+
+    assert api_base == "https://example.test/anthropic"
+    assert headers["x-api-key"] == "sk-zai"
+    assert headers["anthropic-version"] == "2023-06-01"
+    assert headers["content-type"] == "application/json"

tests/test_litellm/llms/zai/test_zai_responses_transformation.py

@@ -0,0 +1,57 @@
+import litellm
+from litellm.llms.zai.responses.transformation import ZAIResponsesAPIConfig
+from litellm.types.router import GenericLiteLLMParams
+from litellm.types.utils import LlmProviders
+from litellm.utils import ProviderConfigManager
+
+
+def test_zai_provider_uses_responses_api_config():
+    config = ProviderConfigManager.get_provider_responses_api_config(
+        model="glm-5.3",
+        provider=litellm.LlmProviders.ZAI,
+    )
+
+    assert isinstance(config, ZAIResponsesAPIConfig)
+    assert config.custom_llm_provider == LlmProviders.ZAI
+
+
+def test_zai_responses_url_defaults_to_responses_endpoint(monkeypatch):
+    monkeypatch.delenv("ZAI_RESPONSES_API_BASE", raising=False)
+    config = ZAIResponsesAPIConfig()
+
+    url_cases = {
+        None: "https://api.z.ai/api/v1/responses",
+        "https://api.z.ai/api/v1": "https://api.z.ai/api/v1/responses",
+        "https://api.z.ai/api/v1/": "https://api.z.ai/api/v1/responses",
+        "https://api.z.ai/api/v1/responses": "https://api.z.ai/api/v1/responses",
+    }
+
+    for api_base, expected_url in url_cases.items():
+        assert config.get_complete_url(api_base=api_base, litellm_params={}) == expected_url
+
+
+def test_zai_responses_headers_use_bearer_token():
+    config = ZAIResponsesAPIConfig()
+    litellm_params = GenericLiteLLMParams(api_key="sk-zai")
+
+    headers = config.validate_environment(
+        headers={},
+        model="glm-5.3",
+        litellm_params=litellm_params,
+    )
+
+    assert headers["Authorization"] == "Bearer sk-zai"
+    assert headers["Content-Type"] == "application/json"
+
+
+def test_zai_responses_headers_fall_back_to_environment_key(monkeypatch):
+    monkeypatch.setenv("ZAI_API_KEY", "sk-zai-env")
+    config = ZAIResponsesAPIConfig()
+
+    headers = config.validate_environment(
+        headers={},
+        model="glm-5.3",
+        litellm_params=GenericLiteLLMParams(),
+    )
+
+    assert headers["Authorization"] == "Bearer sk-zai-env"