백엔드 전체 구현 완료: 내부 서비스(Auth, Client, Realtime), API 엔드포인트 및 스케줄러 구현

backend/app/core/rate_limiter.py

@@ -0,0 +1,35 @@
+import asyncio
+import time
+
+class RateLimiter:
+    """
+    Centralized Request Queue that enforces a physical delay between API calls.
+    Default delay is 250ms (4 requests per second).
+    """
+    def __init__(self):
+        self._lock = asyncio.Lock()
+        self._last_call_time = 0
+        self._delay = 0.25  # seconds (250ms)
+
+    async def wait(self):
+        """
+        Acquire lock and sleep if necessary to respect the rate limit.
+        """
+        async with self._lock:
+            now = time.monotonic()
+            elapsed = now - self._last_call_time
+            
+            if elapsed < self._delay:
+                sleep_time = self._delay - elapsed
+                await asyncio.sleep(sleep_time)
+            
+            self._last_call_time = time.monotonic()
+
+    def set_delay(self, ms: int):
+        """
+        Update the delay interval dynamically from DB settings.
+        """
+        self._delay = ms / 1000.0
+
+# Singleton instance
+global_rate_limiter = RateLimiter()