add the code

app.py

@@ -0,0 +1,33 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from schemas import CodeXRequest, CodeXResponse
+from code_engine import process_codex_request
+from config import settings
+
+app = FastAPI(
+    title=settings.APP_NAME,
+    version=settings.APP_VERSION,
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+
+@app.get("/")
+def health_check():
+    return {
+        "status": "ok",
+        "service": settings.APP_NAME,
+        "version": settings.APP_VERSION,
+    }
+
+
+@app.post("/codex", response_model=CodeXResponse)
+def codex_endpoint(request: CodeXRequest):
+    return process_codex_request(request)