Create server.pt

src/server.pt

@@ -0,0 +1,84 @@
+# server.py
+import os
+import json
+from typing import List, Optional, AsyncGenerator
+from fastapi import FastAPI, HTTPException, Header
+from fastapi.responses import StreamingResponse
+from pydantic import BaseModel
+import httpx
+
+SERVER_API_KEY = os.getenv("OPENROUTER_API_KEY")  # optional fallback
+OPENROUTER_BASE_URL = "https://openrouter.ai/api/v1/chat/completions"
+DEFAULT_MODEL = "openai/gpt-4o-mini"  # change as desired
+
+app = FastAPI(title="OpenRouter Chat Backend")
+
+
+class Message(BaseModel):
+    role: str  # "system" | "user" | "assistant"
+    content: str
+
+
+class ChatRequest(BaseModel):
+    messages: List[Message]
+    model: Optional[str] = None
+    temperature: Optional[float] = 0.7
+    max_tokens: Optional[int] = None
+
+
+@app.post("/chat")
+async def chat(
+    req: ChatRequest,
+    x_openrouter_api_key: Optional[str] = Header(default=None, alias="X-OpenRouter-Api-Key"),
+    http_referer: Optional[str] = Header(default=None, alias="HTTP-Referer"),
+):
+    model = req.model or DEFAULT_MODEL
+    # Prefer per-request key from client; fallback to server key if available
+    api_key = x_openrouter_api_key or SERVER_API_KEY
+    if not api_key:
+        raise HTTPException(status_code=401, detail="Missing OpenRouter API key")
+
+    headers = {
+        "Authorization": f"Bearer {api_key}",
+        "Content-Type": "application/json",
+        # Attribution headers (optional)
+        "HTTP-Referer": http_referer or "http://localhost:8501",
+        "X-Title": "OpenRouter Streamlit Chat",
+    }
+    payload = {
+        "model": model,
+        "messages": [m.dict() for m in req.messages],
+        "temperature": req.temperature,
+        "max_tokens": req.max_tokens,
+        "stream": True,
+    }
+
+    async def stream() -> AsyncGenerator[bytes, None]:
+        try:
+            async with httpx.AsyncClient(timeout=None) as client:
+                async with client.stream("POST", OPENROUTER_BASE_URL, headers=headers, json=payload) as r:
+                    if r.status_code >= 400:
+                        text = await r.aread()
+                        raise HTTPException(status_code=r.status_code, detail=text.decode("utf-8"))
+                    async for line in r.aiter_lines():
+                        if not line:
+                            continue
+                        if line.startswith("data: "):
+                            data = line[len("data: "):]
+                            if data.strip() == "[DONE]":
+                                yield b"event: done\ndata: done\n\n"
+                                break
+                            try:
+                                obj = json.loads(data)
+                                delta = obj.get("choices", [{}])[0].get("delta", {})
+                                content = delta.get("content")
+                                if content:
+                                    yield f"data: {json.dumps({'content': content})}\n\n".encode("utf-8")
+                            except Exception:
+                                yield f"data: {json.dumps({'raw': data})}\n\n".encode("utf-8")
+        except HTTPException:
+            raise
+        except Exception as e:
+            raise HTTPException(status_code=500, detail=str(e))
+
+    return StreamingResponse(stream(), media_type="text/event-stream")