diff --git a/requirements.txt b/requirements.txt
index b859ad08a..2f806b315 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,6 +5,7 @@ langchain==0.3.27
 langchain_community==0.3.29
 msal==1.31.0
 openai==1.66.2
+litellm>=1.80,<1.87
 Pillow==11.3.0
 PyPDF2==3.0.1; sys_platform == 'win32'
 protobuf==4.25.8
diff --git a/ufo/llm/base.py b/ufo/llm/base.py
index be81960d5..501dd23c4 100644
--- a/ufo/llm/base.py
+++ b/ufo/llm/base.py
@@ -42,6 +42,7 @@ def get_service(
             "custom": "CustomService",
             "operator": "OperatorServicePreview",
             "placeholder": "PlaceHolderService",
+            "litellm": "LiteLLMService",
         }
         custom_service_map = {
             "llava": "LlavaService",
@@ -145,6 +146,8 @@ def get_cost_estimator(
             name = str("gemini/" + model)
         elif api_type.lower() == "claude":
             name = str("claude/" + model)
+        elif api_type.lower() == "litellm":
+            name = model
         else:
             name = model
 
diff --git a/ufo/llm/litellm.py b/ufo/llm/litellm.py
new file mode 100644
index 000000000..9a98321c5
--- /dev/null
+++ b/ufo/llm/litellm.py
@@ -0,0 +1,133 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+import logging
+import time
+from typing import Any, Dict, List, Optional, Tuple
+
+from ufo.llm.base import BaseService
+
+logger = logging.getLogger(__name__)
+
+
+class LiteLLMService(BaseService):
+    """
+    A service class for LiteLLM — access 100+ LLM providers
+    (OpenAI, Anthropic, Google, Azure, Bedrock, Cohere, Mistral, etc.)
+    through a single unified interface.
+
+    Models are specified with provider-prefixed names, e.g.:
+        anthropic/claude-sonnet-4-6
+        openai/gpt-4o
+        gemini/gemini-2.5-pro
+        bedrock/anthropic.claude-3-5-sonnet-20241022-v2:0
+    """
+
+    def __init__(self, config: Dict[str, Any], agent_type: str):
+        """
+        Initialize the LiteLLM service.
+        :param config: The configuration dictionary.
+        :param agent_type: The agent type.
+        """
+        self.config_llm = config[agent_type]
+        self.config = config
+        self.model = self.config_llm["API_MODEL"]
+        self.prices = self.config.get("PRICES", {})
+        self.max_retry = self.config.get("MAX_RETRY", 3)
+        self.api_type = self.config_llm["API_TYPE"].lower()
+
+        self.api_key = self.config_llm.get("API_KEY", "")
+        self.api_base = self.config_llm.get("API_BASE", "")
+
+        try:
+            import litellm  # noqa: F401
+        except ImportError:
+            raise ImportError(
+                "litellm is not installed. "
+                "Install with: pip install litellm>=1.80,<1.87"
+            )
+
+    def chat_completion(
+        self,
+        messages: List[Dict[str, str]],
+        n: int = 1,
+        temperature: Optional[float] = None,
+        max_tokens: Optional[int] = None,
+        top_p: Optional[float] = None,
+        **kwargs: Any,
+    ) -> Tuple[List[str], Optional[float]]:
+        """
+        Generates completions using LiteLLM (100+ providers).
+        :param messages: The list of messages in the conversation.
+        :param n: The number of completions to generate.
+        :param temperature: The temperature parameter for randomness.
+        :param max_tokens: The maximum number of tokens in the response.
+        :param top_p: The top-p parameter for nucleus sampling.
+        :param kwargs: Additional keyword arguments.
+        :return: A tuple of (list of response strings, estimated cost).
+        """
+        import litellm
+
+        temperature = (
+            temperature if temperature is not None else self.config.get("TEMPERATURE", 0.0)
+        )
+        max_tokens = (
+            max_tokens if max_tokens is not None else self.config.get("MAX_TOKENS", 2000)
+        )
+
+        responses = []
+        cost = 0.0
+
+        call_kwargs = {
+            "model": self.model,
+            "messages": messages,
+            "temperature": temperature,
+            "max_tokens": max_tokens,
+            "drop_params": True,
+            **kwargs,
+        }
+        if self.api_key:
+            call_kwargs["api_key"] = self.api_key
+        if self.api_base:
+            call_kwargs["api_base"] = self.api_base
+
+        for _ in range(n):
+            for attempt in range(self.max_retry):
+                try:
+                    response = litellm.completion(**call_kwargs)
+                    if not response.choices:
+                        raise ValueError("LiteLLM returned empty choices list")
+                    content = response.choices[0].message.content or ""
+                    responses.append(content)
+
+                    usage = getattr(response, "usage", None)
+                    prompt_tokens = getattr(usage, "prompt_tokens", 0) or 0
+                    completion_tokens = getattr(usage, "completion_tokens", 0) or 0
+
+                    cost += self.get_cost_estimator(
+                        self.api_type,
+                        self.model,
+                        self.prices,
+                        prompt_tokens,
+                        completion_tokens,
+                    )
+                    break
+                except Exception as e:
+                    qualname = f"{type(e).__module__}.{type(e).__name__}"
+                    is_transient = qualname in {
+                        "litellm.exceptions.RateLimitError",
+                        "litellm.exceptions.APIConnectionError",
+                        "litellm.exceptions.Timeout",
+                        "litellm.exceptions.InternalServerError",
+                        "litellm.exceptions.ServiceUnavailableError",
+                        "litellm.exceptions.BadGatewayError",
+                    }
+                    if not is_transient or attempt >= self.max_retry - 1:
+                        logger.error(f"LiteLLM API error: {e}")
+                        raise
+                    logger.warning(
+                        f"LiteLLM transient error (attempt {attempt + 1}/{self.max_retry}): {e}"
+                    )
+                    time.sleep(2**attempt)
+
+        return responses, cost