feat: add DeepSeek provider support in client and utils

cli/utils.py

@@ -160,6 +160,10 @@ def select_shallow_thinking_agent(provider) -> str:
             ("GPT-OSS:latest (20B, local)", "gpt-oss:latest"),
             ("GLM-4.7-Flash:latest (30B, local)", "glm-4.7-flash:latest"),
         ],
+        "deepseek": [
+            ("DeepSeek-V3.2(Non-thinking Mode) - Fast, general-purpose", "deepseek-chat"),
+            ("DeepSeek-V3.2(Thinking Mode) - More thorough analysis", "deepseek-reasoner"),
+        ]
     }
 
     choice = questionary.select(
@@ -228,6 +232,10 @@ def select_deep_thinking_agent(provider) -> str:
             ("GPT-OSS:latest (20B, local)", "gpt-oss:latest"),
             ("Qwen3:latest (8B, local)", "qwen3:latest"),
         ],
+        "deepseek": [
+            ("DeepSeek-V3.2(Non-thinking Mode) - Fast, general-purpose", "deepseek-chat"),
+            ("DeepSeek-V3.2(Thinking Mode) - More thorough analysis", "deepseek-reasoner"),
+        ]
     }
 
     choice = questionary.select(
@@ -262,6 +270,7 @@ def select_llm_provider() -> tuple[str, str]:
         ("xAI", "https://api.x.ai/v1"),
         ("Openrouter", "https://openrouter.ai/api/v1"),
         ("Ollama", "http://localhost:11434/v1"),
+        ("DeepSeek", "https://api.deepseek.com"),
     ]
     
     choice = questionary.select(

tradingagents/llm_clients/factory.py

@@ -30,6 +30,9 @@ def create_llm_client(
 
     if provider_lower in ("openai", "ollama", "openrouter"):
         return OpenAIClient(model, base_url, provider=provider_lower, **kwargs)
+    
+    if provider_lower == "deepseek":
+        return OpenAIClient(model, base_url, provider="deepseek", **kwargs)
 
     if provider_lower == "xai":
         return OpenAIClient(model, base_url, provider="xai", **kwargs)

tradingagents/llm_clients/openai_client.py

@@ -50,6 +50,13 @@ class OpenAIClient(BaseLLMClient):
             api_key = os.environ.get("XAI_API_KEY")
             if api_key:
                 llm_kwargs["api_key"] = api_key
+        elif self.provider == "deepseek":
+            llm_kwargs["base_url"] = "https://api.deepseek.com"
+            api_key = os.environ.get("DEEPSEEK_API_KEY")
+            if api_key:
+                llm_kwargs["api_key"] = api_key
+            else:
+                raise ValueError("DEEPSEEK_API_KEY environment variable is required for DeepSeek provider")
         elif self.provider == "openrouter":
             llm_kwargs["base_url"] = "https://openrouter.ai/api/v1"
             api_key = os.environ.get("OPENROUTER_API_KEY")