feat: add Azure OpenAI provider support

- Add AzureOpenAIProvider class using openai.AzureOpenAI client
- Auto-detect Azure when AZURE_OPENAI_ENDPOINT env var is set
- Add AZURE_OPENAI_API_VERSION support (default: 2024-08-01-preview)
- Update .env.example with Azure config section
- Update docstring with Azure setup instructions

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lijunliu-gh

.env.example

@@ -4,6 +4,12 @@ OPENAI_API_KEY=
 OPENAI_MODEL=gpt-4.1-mini
 OPENAI_BASE_URL=
 
+# Azure OpenAI (set AZURE_OPENAI_ENDPOINT to auto-select this provider)
+# AZURE_OPENAI_ENDPOINT=https://<your-resource>.openai.azure.com
+# OPENAI_API_KEY=<your-azure-api-key>
+# OPENAI_MODEL=<your-deployment-name>       # e.g. gpt-4o
+# AZURE_OPENAI_API_VERSION=2024-08-01-preview
+
 # OpenRouter (optional, alternative multi-model gateway)
 OPENROUTER_API_KEY=
 

python_backend/llm_provider.py

@@ -8,6 +8,12 @@
     export OPENAI_API_KEY="sk-..."
     export OPENAI_MODEL="gpt-4.1-mini"       # or o3, o4-mini, codex-mini-latest
 
+    # Azure OpenAI
+    export AZURE_OPENAI_ENDPOINT="https://<resource>.openai.azure.com"
+    export OPENAI_API_KEY="<azure-api-key>"
+    export OPENAI_MODEL="<deployment-name>"  # your deployment name, e.g. gpt-4o
+    export AZURE_OPENAI_API_VERSION="2024-08-01-preview"  # optional
+
     # Anthropic Claude
     export ANTHROPIC_API_KEY="sk-ant-..."
     export OPENAI_MODEL="claude-sonnet-4-20250514"
@@ -129,6 +135,107 @@ def chat(self, system_prompt: str, user_prompt: str) -> str:
         return str(content)
 
 
+# ---------------------------------------------------------------------------
+# Azure OpenAI
+# ---------------------------------------------------------------------------
+
+
+class AzureOpenAIProvider:
+    """Provider backed by Azure OpenAI Service.
+
+    Requires the ``openai`` package (already a dependency).
+    Set ``AZURE_OPENAI_ENDPOINT`` to enable auto-detection.
+
+    Required env vars::
+
+        AZURE_OPENAI_ENDPOINT   https://<resource>.openai.azure.com
+        OPENAI_API_KEY          your Azure OpenAI API key
+        OPENAI_MODEL            your deployment name (e.g. gpt-4o)
+
+    Optional::
+
+        AZURE_OPENAI_API_VERSION  API version (default: 2024-08-01-preview)
+    """
+
+    _DEFAULT_API_VERSION = "2024-08-01-preview"
+    _REASONING_PREFIXES = ("o1", "o3", "o4", "codex")
+
+    def __init__(
+        self,
+        api_key: str | None = None,
+        endpoint: str | None = None,
+        model: str | None = None,
+        api_version: str | None = None,
+    ) -> None:
+        AzureOpenAI = importlib.import_module("openai").AzureOpenAI
+
+        resolved_key = api_key or os.getenv("OPENAI_API_KEY")
+        if not resolved_key:
+            raise RuntimeError(
+                "OPENAI_API_KEY is not set. "
+                "Set OPENAI_API_KEY to your Azure OpenAI API key."
+            )
+        resolved_endpoint = endpoint or os.getenv("AZURE_OPENAI_ENDPOINT")
+        if not resolved_endpoint:
+            raise RuntimeError(
+                "AZURE_OPENAI_ENDPOINT is not set. "
+                "Set it to https://<resource>.openai.azure.com"
+            )
+        resolved_version = (
+            api_version
+            or os.getenv("AZURE_OPENAI_API_VERSION")
+            or self._DEFAULT_API_VERSION
+        )
+        # Strip path/query from endpoint — AzureOpenAI expects the base URL only
+        from urllib.parse import urlparse
+        parsed = urlparse(resolved_endpoint)
+        base_endpoint = f"{parsed.scheme}://{parsed.netloc}"
+
+        self._client: Any = AzureOpenAI(
+            api_key=resolved_key,
+            azure_endpoint=base_endpoint,
+            api_version=resolved_version,
+        )
+        self._model = model or os.getenv("OPENAI_MODEL") or "gpt-4o"
+        logger.info(
+            "AzureOpenAIProvider: endpoint=%s model=%s api_version=%s",
+            base_endpoint,
+            self._model,
+            resolved_version,
+        )
+
+    def _is_reasoning_model(self) -> bool:
+        return self._model.startswith(self._REASONING_PREFIXES)
+
+    def chat(self, system_prompt: str, user_prompt: str) -> str:
+        logger.info("Requesting deck JSON from Azure model=%s", self._model)
+        reasoning = self._is_reasoning_model()
+
+        instruction_role = "developer" if reasoning else "system"
+        messages = [
+            {"role": instruction_role, "content": system_prompt},
+            {"role": "user", "content": user_prompt},
+        ]
+
+        params: dict[str, Any] = {
+            "model": self._model,
+            "response_format": {"type": "json_object"},
+            "messages": messages,
+        }
+
+        if reasoning:
+            effort = os.getenv("OPENAI_REASONING_EFFORT", "medium")
+            params["reasoning_effort"] = effort
+        else:
+            params["temperature"] = 0.3
+
+        response = self._client.chat.completions.create(**params)
+        content = response.choices[0].message.content if response.choices else None
+        if not content:
+            raise RuntimeError("Model returned no content.")
+        return str(content)
+
+
 # ---------------------------------------------------------------------------
 # Anthropic Claude
 # ---------------------------------------------------------------------------
@@ -292,12 +399,18 @@ def get_default_provider() -> LLMProvider:
     """Return the best provider based on environment variables.
 
     Detection order:
-    1. If ``OPENROUTER_API_KEY`` is set -> OpenRouterProvider
-    2. Read ``OPENAI_MODEL`` (or default ``gpt-4.1-mini``)
-    3. If model starts with ``claude`` -> AnthropicProvider
-    4. If model starts with ``gemini`` -> GeminiProvider
-    5. Otherwise -> OpenAIProvider (works for OpenAI, Qwen, DeepSeek, GLM, MiniMax, etc.)
+    1. If ``AZURE_OPENAI_ENDPOINT`` is set -> AzureOpenAIProvider
+    2. If ``OPENROUTER_API_KEY`` is set -> OpenRouterProvider
+    3. Read ``OPENAI_MODEL`` (or default ``gpt-4.1-mini``)
+    4. If model starts with ``claude`` -> AnthropicProvider
+    5. If model starts with ``gemini`` -> GeminiProvider
+    6. Otherwise -> OpenAIProvider (works for OpenAI, Qwen, DeepSeek, GLM, MiniMax, etc.)
     """
+    if os.getenv("AZURE_OPENAI_ENDPOINT"):
+        model = os.getenv("OPENAI_MODEL") or "gpt-4o"
+        logger.info("Auto-detected provider AzureOpenAIProvider for model=%s", model)
+        return AzureOpenAIProvider(model=model)
+
     if os.getenv("OPENROUTER_API_KEY"):
         model = os.getenv("OPENAI_MODEL") or "openai/gpt-4.1-mini"
         logger.info("Auto-detected provider OpenRouterProvider for model=%s", model)