From 6ea15cc5e5cab24df67a4925b08bd14264fb379e Mon Sep 17 00:00:00 2001
From: Guy Khmelnitsky <guykhmel@gmail.com>
Date: Sun, 15 Feb 2026 15:24:22 +0200
Subject: [PATCH 1/2] Add API rate limiter with exponential backoff retry

Add a semaphore-based rate limiter (max 3 concurrent requests) and
a helper method for executing API calls with retry logic and
exponential backoff (3 retries, starting at 1s delay).
---
 custom_components/iec/coordinator.py | 43 ++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/custom_components/iec/coordinator.py b/custom_components/iec/coordinator.py
index 9136c58..4cd8d54 100644
--- a/custom_components/iec/coordinator.py
+++ b/custom_components/iec/coordinator.py
@@ -118,6 +118,7 @@ def __init__(
             session=aiohttp_client.async_get_clientsession(hass, family=socket.AF_INET),
         )
         self._first_load: bool = True
+        self._api_rate_limiter = asyncio.Semaphore(3)
 
         @callback
         def _dummy_listener() -> None:
@@ -133,6 +134,48 @@ async def async_unload(self):
         """Unload the coordinator, cancel any pending tasks."""
         _LOGGER.info("Coordinator unloaded successfully.")
 
+    async def _execute_with_rate_limit(
+        self,
+        coro,
+        max_retries: int = 3,
+        base_delay: float = 1.0,
+    ):
+        """Execute an API call with rate limiting and retry logic.
+
+        Args:
+            coro: The coroutine to execute
+            max_retries: Maximum number of retries
+            base_delay: Base delay in seconds for exponential backoff
+
+        Returns:
+            The result of the coroutine
+
+        Raises:
+            The last exception if all retries fail
+        """
+        last_exception = None
+        for attempt in range(max_retries):
+            async with self._api_rate_limiter:
+                try:
+                    return await coro
+                except IECError as e:
+                    last_exception = e
+                    if attempt < max_retries - 1:
+                        delay = base_delay * (2**attempt)
+                        _LOGGER.warning(
+                            "API call failed (attempt %d/%d), retrying in %.1fs: %s",
+                            attempt + 1,
+                            max_retries,
+                            delay,
+                            e,
+                        )
+                        await asyncio.sleep(delay)
+                    else:
+                        _LOGGER.error(
+                            "API call failed after %d attempts: %s", max_retries, e
+                        )
+        raise last_exception
+
     async def _get_devices_by_contract_id(self, contract_id) -> list[Device]:
         devices = self._devices_by_contract_id.get(contract_id)
         if not devices:

From 50655aabfa2b66c242607c3d6d2e74be85f26511 Mon Sep 17 00:00:00 2001
From: Guy Khmelnitsky <guykhmel@gmail.com>
Date: Sun, 15 Feb 2026 15:43:05 +0200
Subject: [PATCH 2/2] Fix ruff lint errors

---
 custom_components/iec/coordinator.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/custom_components/iec/coordinator.py b/custom_components/iec/coordinator.py
index 4cd8d54..562a1cf 100644
--- a/custom_components/iec/coordinator.py
+++ b/custom_components/iec/coordinator.py
@@ -152,6 +152,7 @@ async def _execute_with_rate_limit(
 
         Raises:
             The last exception if all retries fail
+
         """
         last_exception = None
         for attempt in range(max_retries):