feat: Add User-Agent header with SDK identification (#6)

* feat: Add User-Agent header with SDK identification

* format and lint

Author: AdirAmsalem

decart/_user_agent.py

@@ -0,0 +1,31 @@
+"""User-Agent header construction for SDK requests."""
+
+from typing import Optional
+from ._version import __version__
+
+
+def build_user_agent(integration: Optional[str] = None) -> str:
+    """
+    Builds the User-Agent string for the SDK.
+
+    Format: decart-python-sdk/{version} lang/py {integration?}
+
+    Args:
+        integration: Optional integration identifier (e.g., "langchain/0.1.0")
+
+    Returns:
+        Complete User-Agent string
+
+    Examples:
+        >>> build_user_agent()
+        'decart-python-sdk/0.0.6 lang/py'
+
+        >>> build_user_agent("langchain/0.1.0")
+        'decart-python-sdk/0.0.6 lang/py langchain/0.1.0'
+    """
+    parts = [f"decart-python-sdk/{__version__}", "lang/py"]
+
+    if integration:
+        parts.append(integration)
+
+    return " ".join(parts)

decart/_version.py

@@ -0,0 +1,9 @@
+"""SDK version information."""
+
+from importlib.metadata import version, PackageNotFoundError
+
+try:
+    __version__ = version("decart")
+except PackageNotFoundError:
+    # Development version when package is not installed
+    __version__ = "0.0.0-dev"

decart/client.py

@@ -21,6 +21,7 @@ class DecartClient:
     Args:
         api_key: Your Decart API key
         base_url: API base URL (defaults to production)
+        integration: Optional integration identifier (e.g., "langchain/0.1.0")
 
     Example:
         ```python
@@ -32,7 +33,12 @@ class DecartClient:
         ```
     """
 
-    def __init__(self, api_key: str, base_url: str = "https://api.decart.ai") -> None:
+    def __init__(
+        self,
+        api_key: str,
+        base_url: str = "https://api.decart.ai",
+        integration: Optional[str] = None,
+    ) -> None:
         if not api_key or not api_key.strip():
             raise InvalidAPIKeyError()
 
@@ -41,6 +47,7 @@ def __init__(self, api_key: str, base_url: str = "https://api.decart.ai") -> Non
 
         self.api_key = api_key
         self.base_url = base_url
+        self.integration = integration
         self._session: Optional[aiohttp.ClientSession] = None
 
     async def _get_session(self) -> aiohttp.ClientSession:
@@ -117,6 +124,7 @@ async def process(self, options: dict[str, Any]) -> bytes:
             model=model,
             inputs=processed_inputs,
             cancel_token=cancel_token,
+            integration=self.integration,
         )
 
         return response

decart/process/request.py

@@ -6,6 +6,7 @@
 from ..types import FileInput
 from ..models import ModelDefinition
 from ..errors import InvalidInputError, ProcessingError
+from .._user_agent import build_user_agent
 
 
 async def file_input_to_bytes(
@@ -82,6 +83,7 @@ async def send_request(
     model: ModelDefinition,
     inputs: dict[str, Any],
     cancel_token: Optional[asyncio.Event] = None,
+    integration: Optional[str] = None,
 ) -> bytes:
     form_data = aiohttp.FormData()
 
@@ -98,7 +100,10 @@ async def send_request(
     async def make_request() -> bytes:
         async with session.post(
             endpoint,
-            headers={"X-API-KEY": api_key},
+            headers={
+                "X-API-KEY": api_key,
+                "User-Agent": build_user_agent(integration),
+            },
             data=form_data,
         ) as response:
             if not response.ok:

decart/realtime/client.py

@@ -1,4 +1,4 @@
-from typing import Callable
+from typing import Callable, Optional
 import logging
 import uuid
 from aiortc import MediaStreamTrack
@@ -25,6 +25,7 @@ async def connect(
         api_key: str,
         local_track: MediaStreamTrack,
         options: RealtimeConnectOptions,
+        integration: Optional[str] = None,
     ) -> "RealtimeClient":
         session_id = str(uuid.uuid4())
         ws_url = f"{base_url}{options.model.url_path}"
@@ -40,6 +41,7 @@ async def connect(
             on_error=None,
             initial_state=options.initial_state,
             customize_offer=options.customize_offer,
+            integration=integration,
         )
 
         manager = WebRTCManager(config)

decart/realtime/webrtc_connection.py

@@ -2,6 +2,7 @@
 import json
 import logging
 from typing import Optional, Callable
+from urllib.parse import quote
 import aiohttp
 from aiortc import (
     RTCPeerConnection,
@@ -13,6 +14,7 @@
 )
 
 from ..errors import WebRTCError
+from .._user_agent import build_user_agent
 from .messages import (
     parse_incoming_message,
     message_to_json,
@@ -46,12 +48,23 @@ def __init__(
         self._ws_task: Optional[asyncio.Task] = None
         self._ice_candidates_queue: list[RTCIceCandidate] = []
 
-    async def connect(self, url: str, local_track: MediaStreamTrack, timeout: float = 30) -> None:
+    async def connect(
+        self,
+        url: str,
+        local_track: MediaStreamTrack,
+        timeout: float = 30,
+        integration: Optional[str] = None,
+    ) -> None:
         try:
             await self._set_state("connecting")
 
             ws_url = url.replace("https://", "wss://").replace("http://", "ws://")
 
+            # Add user agent as query parameter (browsers don't support WS headers)
+            user_agent = build_user_agent(integration)
+            separator = "&" if "?" in ws_url else "?"
+            ws_url = f"{ws_url}{separator}user_agent={quote(user_agent)}"
+
             self._session = aiohttp.ClientSession()
             self._ws = await self._session.ws_connect(ws_url)
 

decart/realtime/webrtc_manager.py

@@ -29,6 +29,7 @@ class WebRTCConfiguration:
     on_error: Optional[Callable[[Exception], None]] = None
     initial_state: Optional[ModelState] = None
     customize_offer: Optional[Callable] = None
+    integration: Optional[str] = None
 
 
 def _is_retryable_error(exception: Exception) -> bool:
@@ -55,6 +56,7 @@ async def connect(self, local_track: MediaStreamTrack) -> bool:
             await self._connection.connect(
                 url=self._config.webrtc_url,
                 local_track=local_track,
+                integration=self._config.integration,
             )
             return True
         except Exception as e:

tests/test_process.py

@@ -101,3 +101,77 @@ async def test_process_with_cancellation() -> None:
                 "cancel_token": cancel_token,
             }
         )
+
+
+@pytest.mark.asyncio
+async def test_process_includes_user_agent_header() -> None:
+    """Test that User-Agent header is included in requests."""
+    client = DecartClient(api_key="test-key")
+
+    with patch("aiohttp.ClientSession") as mock_session_cls:
+        mock_response = MagicMock()
+        mock_response.ok = True
+        mock_response.read = AsyncMock(return_value=b"fake video data")
+
+        mock_session = MagicMock()
+        mock_session.__aenter__ = AsyncMock(return_value=mock_session)
+        mock_session.__aexit__ = AsyncMock(return_value=None)
+        mock_session.post = MagicMock()
+        mock_session.post.return_value.__aenter__ = AsyncMock(return_value=mock_response)
+        mock_session.post.return_value.__aexit__ = AsyncMock(return_value=None)
+
+        mock_session_cls.return_value = mock_session
+
+        await client.process(
+            {
+                "model": models.video("lucy-pro-t2v"),
+                "prompt": "Test prompt",
+            }
+        )
+
+        # Verify post was called with User-Agent header
+        mock_session.post.assert_called_once()
+        call_kwargs = mock_session.post.call_args[1]
+        headers = call_kwargs.get("headers", {})
+
+        assert "User-Agent" in headers
+        assert headers["User-Agent"].startswith("decart-python-sdk/")
+        assert "lang/py" in headers["User-Agent"]
+
+
+@pytest.mark.asyncio
+async def test_process_includes_integration_in_user_agent() -> None:
+    """Test that integration parameter is included in User-Agent header."""
+    client = DecartClient(api_key="test-key", integration="langchain/0.1.0")
+
+    with patch("aiohttp.ClientSession") as mock_session_cls:
+        mock_response = MagicMock()
+        mock_response.ok = True
+        mock_response.read = AsyncMock(return_value=b"fake video data")
+
+        mock_session = MagicMock()
+        mock_session.__aenter__ = AsyncMock(return_value=mock_session)
+        mock_session.__aexit__ = AsyncMock(return_value=None)
+        mock_session.post = MagicMock()
+        mock_session.post.return_value.__aenter__ = AsyncMock(return_value=mock_response)
+        mock_session.post.return_value.__aexit__ = AsyncMock(return_value=None)
+
+        mock_session_cls.return_value = mock_session
+
+        await client.process(
+            {
+                "model": models.video("lucy-pro-t2v"),
+                "prompt": "Test prompt",
+            }
+        )
+
+        # Verify post was called with User-Agent header including integration
+        mock_session.post.assert_called_once()
+        call_kwargs = mock_session.post.call_args[1]
+        headers = call_kwargs.get("headers", {})
+
+        assert "User-Agent" in headers
+        assert headers["User-Agent"].startswith("decart-python-sdk/")
+        assert "lang/py" in headers["User-Agent"]
+        assert "langchain/0.1.0" in headers["User-Agent"]
+        assert headers["User-Agent"].endswith(" langchain/0.1.0")

tests/test_user_agent.py

@@ -0,0 +1,27 @@
+"""Tests for User-Agent header construction."""
+
+from decart._user_agent import build_user_agent
+from decart._version import __version__
+
+
+def test_build_user_agent_without_integration():
+    """Test User-Agent without integration parameter."""
+    user_agent = build_user_agent()
+
+    assert user_agent == f"decart-python-sdk/{__version__} lang/py"
+    assert user_agent.startswith("decart-python-sdk/")
+    assert "lang/py" in user_agent
+
+
+def test_build_user_agent_with_integration():
+    """Test User-Agent with integration parameter."""
+    user_agent = build_user_agent("langchain/0.1.0")
+
+    expected = f"decart-python-sdk/{__version__} lang/py langchain/0.1.0"
+    assert user_agent == expected
+
+    parts = user_agent.split(" ")
+    assert len(parts) == 3
+    assert parts[0].startswith("decart-python-sdk/")
+    assert parts[1] == "lang/py"
+    assert parts[2] == "langchain/0.1.0"