From be5b496ad8289df6b1974b94a15bf8d0ff25fafc Mon Sep 17 00:00:00 2001
From: Cursor Agent <cursoragent@cursor.com>
Date: Mon, 11 May 2026 22:43:36 +0000
Subject: [PATCH] refactor(proxy/hooks): raise ProxyRateLimitError from dynamic
 rate limiters

Replaces HTTPException(status_code=429, ...) call sites in the v1 and v3
dynamic rate limiters (project-level TPM/RPM allocation, model-saturation
checks, priority-based limits, fail-closed guards) with ProxyRateLimitError.
The v3 limiter still imports HTTPException for an unrelated bare 'except
HTTPException:' branch.

LIT-2968

Co-authored-by: Mateo Wang <mateo-berri@users.noreply.github.com>
---
 litellm/proxy/hooks/dynamic_rate_limiter.py    |  9 +++------
 litellm/proxy/hooks/dynamic_rate_limiter_v3.py | 10 ++++------
 2 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/litellm/proxy/hooks/dynamic_rate_limiter.py b/litellm/proxy/hooks/dynamic_rate_limiter.py
index f1c1d487cc1..00cbd135692 100644
--- a/litellm/proxy/hooks/dynamic_rate_limiter.py
+++ b/litellm/proxy/hooks/dynamic_rate_limiter.py
@@ -6,14 +6,13 @@ import asyncio
 import os
 from typing import List, Optional, Tuple, Union
 
-from fastapi import HTTPException
-
 import litellm
 from litellm import ModelResponse, Router
 from litellm._logging import verbose_proxy_logger
 from litellm.caching.caching import DualCache
 from litellm.integrations.custom_logger import CustomLogger
 from litellm.proxy._types import UserAPIKeyAuth
+from litellm.proxy.common_utils.proxy_rate_limit_error import ProxyRateLimitError
 from litellm.types.router import ModelGroupInfo
 from litellm.types.utils import CallTypesLiteral
 from litellm.utils import get_utc_datetime
@@ -218,8 +217,7 @@ class _PROXY_DynamicRateLimitHandler(CustomLogger):
             )
             ### CHECK TPM ###
             if available_tpm is not None and available_tpm == 0:
-                raise HTTPException(
-                    status_code=429,
+                raise ProxyRateLimitError(
                     detail={
                         "error": "Key={} over available TPM={}. Model TPM={}, Active keys={}".format(
                             user_api_key_dict.api_key,
@@ -231,8 +229,7 @@ class _PROXY_DynamicRateLimitHandler(CustomLogger):
                 )
             ### CHECK RPM ###
             elif available_rpm is not None and available_rpm == 0:
-                raise HTTPException(
-                    status_code=429,
+                raise ProxyRateLimitError(
                     detail={
                         "error": "Key={} over available RPM={}. Model RPM={}, Active keys={}".format(
                             user_api_key_dict.api_key,
diff --git a/litellm/proxy/hooks/dynamic_rate_limiter_v3.py b/litellm/proxy/hooks/dynamic_rate_limiter_v3.py
index 861083e7dfa..312c0561c0b 100644
--- a/litellm/proxy/hooks/dynamic_rate_limiter_v3.py
+++ b/litellm/proxy/hooks/dynamic_rate_limiter_v3.py
@@ -14,6 +14,7 @@ from litellm._logging import verbose_proxy_logger
 from litellm.caching.caching import DualCache
 from litellm.integrations.custom_logger import CustomLogger
 from litellm.proxy._types import UserAPIKeyAuth
+from litellm.proxy.common_utils.proxy_rate_limit_error import ProxyRateLimitError
 from litellm.proxy.hooks.parallel_request_limiter_v3 import (
     RateLimitDescriptor,
     RateLimitDescriptorRateLimitObject,
@@ -492,8 +493,7 @@ class _PROXY_DynamicRateLimitHandlerV3(CustomLogger):
                     continue
                 descriptor_key = status["descriptor_key"]
                 if descriptor_key == "model_saturation_check":
-                    raise HTTPException(
-                        status_code=429,
+                    raise ProxyRateLimitError(
                         detail={
                             "error": f"Model capacity reached for {model}. "
                             f"Priority: {priority}, "
@@ -513,8 +513,7 @@ class _PROXY_DynamicRateLimitHandlerV3(CustomLogger):
                         f"Enforcing priority limits for {model}, saturation: {saturation:.1%}, "
                         f"priority: {priority}"
                     )
-                    raise HTTPException(
-                        status_code=429,
+                    raise ProxyRateLimitError(
                         detail={
                             "error": f"Priority-based rate limit exceeded. "
                             f"Model: {model}, "
@@ -547,8 +546,7 @@ class _PROXY_DynamicRateLimitHandlerV3(CustomLogger):
                 f"Dynamic rate limiter: OVER_LIMIT response with unknown "
                 f"descriptor_key(s) — refusing request. response={atomic_response}"
             )
-            raise HTTPException(
-                status_code=429,
+            raise ProxyRateLimitError(
                 detail={
                     "error": "Rate limit exceeded",
                     "descriptor_key": (