app/middleware/timing.py

"""
Request timing middleware.
Emits one structured log line per request with method, path, status, and duration.
"""
import logging
import time

from starlette.middleware.base import BaseHTTPMiddleware
from starlette.requests import Request

logger = logging.getLogger(__name__)


class TimingMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request: Request, call_next):
        start = time.perf_counter()
        response = await call_next(request)
        duration_ms = round((time.perf_counter() - start) * 1000, 2)
        logger.info(
            "request completed",
            extra={
                "method": request.method,
                "path": request.url.path,
                "status_code": response.status_code,
                "duration_ms": duration_ms,
                "client_ip": request.client.host if request.client else None,
            },
        )
        return response