clean up

app/internal/constants.py

@@ -1,3 +1,3 @@
 DUCKDUCKGO_CHAT_ENDPOINT = 'https://duckduckgo.com/duckchat/v1/chat'
 DUCKDUCKGO_STATUS_ENDPOINT = 'https://duckduckgo.com/duckchat/v1/status'
-DEFAULT_USER_AGENT = 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36'
+SESSION_KEY = 'x-vqd-4'

app/routers/duckduckgo.py

@@ -4,8 +4,8 @@ from fastapi import APIRouter, HTTPException, Header, Request, Response
 from httpx_sse import EventSource
 from sse_starlette.sse import EventSourceResponse
 from starlette.background import BackgroundTask
-from app.internal.constants import DEFAULT_USER_AGENT, DUCKDUCKGO_CHAT_ENDPOINT, DUCKDUCKGO_STATUS_ENDPOINT
-from typing import Annotated, List, Literal, cast
+from app.internal.constants import DUCKDUCKGO_CHAT_ENDPOINT, DUCKDUCKGO_STATUS_ENDPOINT, SESSION_KEY
+from typing import Annotated, AsyncIterator, List, Literal
 from pydantic import BaseModel
 
 DONE = '[DONE]'
@@ -60,30 +60,23 @@ router = APIRouter()
              })
 async def chat(input: Chat, request: Request, response: Response, x_session_id: Annotated[str | None, Header()] = None):
     http_client: httpx.AsyncClient = request.state.http_client
-    session_id = x_session_id or (await http_client.get(DUCKDUCKGO_STATUS_ENDPOINT, headers={
-        'x-vqd-accept': '1',
-        'user-agent': DEFAULT_USER_AGENT,
-    })).headers.get('x-vqd-4')
+    session_id = x_session_id or (await http_client.get(DUCKDUCKGO_STATUS_ENDPOINT, headers={'x-vqd-accept': '1'})).headers.get(SESSION_KEY)
 
     req = http_client.build_request('POST', DUCKDUCKGO_CHAT_ENDPOINT,
                                     json=input.model_dump(exclude={'stream'}),
-                                    headers={
-                                        'x-vqd-4': session_id,
-                                        'user-agent': DEFAULT_USER_AGENT
-                                    })
-    resp = await http_client.send(req, stream=input.stream)
+                                    headers={SESSION_KEY: session_id})
+    resp = await http_client.send(req, stream=True)
 
     if resp.status_code != 200:
         raise HTTPException(status_code=400)
 
-    async def agenerator():
+    async def agenerator() -> AsyncIterator[str]:
         async for event in EventSource(resp).aiter_sse():
             if event.data == DONE:
                 return
 
-            content = cast(dict[str, str], event.json()).get('message')
-            if content:
-                yield content
+            if 'message' in (decoded := event.json()):
+                yield decoded['message']
 
     async def event_generator():
         async for chunk in agenerator():
@@ -97,7 +90,7 @@ async def chat(input: Chat, request: Request, response: Response, x_session_id:
 
         yield DONE
 
-    response.headers['x-session-id'] = resp.headers.get('x-vqd-4')
+    response.headers['x-session-id'] = resp.headers.get(SESSION_KEY)
 
     if input.stream:
         return EventSourceResponse(event_generator(), background=BackgroundTask(resp.aclose), headers=response.headers)