diff --git a/scripts/rate_limit/openai_testing.py b/scripts/rate_limit/openai_testing.py
index 403c453a86..fc8a8bb21d 100644
--- a/scripts/rate_limit/openai_testing.py
+++ b/scripts/rate_limit/openai_testing.py
@@ -4,6 +4,7 @@
 import time
 from collections import defaultdict, deque
 from json import JSONDecodeError
+from typing import Any, Deque, Dict
 
 import httpx
 import openai
@@ -16,10 +17,10 @@
 TOTAL_TOKENS = 0
 ERRORS = 0
 stop_event = asyncio.Event()
-request_times = deque()
-tokens_processed = deque()
+request_times: Deque[float] = deque()
+tokens_processed: Deque[int] = deque()
 log = defaultdict(list)
-error_log = defaultdict(list)
+error_log: Dict[str, Any] = defaultdict(list)
 
 API_URL = "https://api.openai.com/v1/chat/completions"
 openai.api_key = os.environ["OPENAI_API_KEY"]
@@ -31,7 +32,7 @@
 MAX_CONCURRENT_REQUESTS = 20
 
 MAX_QUEUE_SIZE = 40
-request_queue = asyncio.Queue(maxsize=MAX_QUEUE_SIZE)
+request_queue: asyncio.Queue[dict[str, Any]] = asyncio.Queue(maxsize=MAX_QUEUE_SIZE)
 
 prompt = "hello!"
 payload_template = {
@@ -44,25 +45,25 @@
 rate_limiter = OpenAIRateLimiter(openai.api_key)
 
 
-def request_time(bucket_size):
+def request_time(bucket_size: int) -> float:
     global request_times
     recent_request_times = (request_times.popleft() for _ in range(bucket_size))
     return sum(recent_request_times) / bucket_size  # seconds
 
 
-def effective_rate():
+def effective_rate() -> float:
     elapsed_time = time.time() - START_TIME
     global COMPLETED_RESPONSES
     return 60 * COMPLETED_RESPONSES / elapsed_time  # requests per minute
 
 
-def effective_token_rate():
+def effective_token_rate() -> float:
     elapsed_time = time.time() - START_TIME
     global TOTAL_TOKENS
     return 60 * TOTAL_TOKENS / elapsed_time  # requests per minute
 
 
-def print_rate_info():
+def print_rate_info() -> None:
     info_interval = 20
     if len(request_times) > info_interval:
         elapsed_time = time.time() - START_TIME
@@ -83,7 +84,7 @@ def print_rate_info():
         print(info_str)
 
 
-def print_error(response):
+def print_error(response: httpx.Response) -> None:
     if response.status_code != 200:
         elapsed_time = time.time() - START_TIME
 
@@ -96,7 +97,7 @@ def print_error(response):
             error_log["error_payload"].append("no json payload")
 
 
-def initial_token_cost(payload) -> int:
+def initial_token_cost(payload: Dict[str, Any]) -> int:
     """Return the number of tokens used by a list of messages.
 
     Official documentation: https://github.com/openai/openai-cookbook/blob/main/examples/How_to_format_inputs_to_ChatGPT_models.ipynb
@@ -118,15 +119,15 @@ def initial_token_cost(payload) -> int:
     return token_count
 
 
-def response_token_cost(response):
+def response_token_cost(response: httpx.Response) -> int:
     if response.status_code == 200:
-        return response.json()["usage"]["completion_tokens"]
+        return int(response.json()["usage"]["completion_tokens"])
     else:
         return 0
 
 
 @rate_limiter.alimit("gpt-4", initial_token_cost, response_token_cost)
-async def openai_request(payload):
+async def openai_request(payload: Dict[str, Any]) -> httpx.Response:
     async with httpx.AsyncClient() as client:
         response = await client.post(API_URL, headers=HEADERS, json=payload, timeout=None)
         if response.status_code != 200:
@@ -147,13 +148,13 @@ async def openai_request(payload):
         return response
 
 
-async def producer():
+async def producer() -> None:
     while not stop_event.is_set():
         await request_queue.put(payload_template)
         await asyncio.sleep(0.001)
 
 
-async def consumer():
+async def consumer() -> None:
     while not stop_event.is_set():
         global request_queue
         payload = await request_queue.get()
@@ -161,7 +162,7 @@ async def consumer():
         request_queue.task_done()
 
 
-async def main(timeout_duration):
+async def main(timeout_duration: int) -> None:
     producer_task = asyncio.create_task(producer())
     [asyncio.create_task(consumer()) for _ in range(MAX_CONCURRENT_REQUESTS)]
 
diff --git a/src/phoenix/utilities/ratelimits.py b/src/phoenix/utilities/ratelimits.py
index 88c253cad4..13ba02bd59 100644
--- a/src/phoenix/utilities/ratelimits.py
+++ b/src/phoenix/utilities/ratelimits.py
@@ -3,7 +3,7 @@
 import time
 from collections import defaultdict
 from functools import wraps
-from typing import Any, Callable, Dict, TypeVar, Union
+from typing import Any, Awaitable, Callable, Dict, TypeVar, Union, cast
 
 if sys.version_info < (3, 10):
     from typing_extensions import ParamSpec
@@ -13,6 +13,7 @@
 Numeric = Union[int, float]
 P = ParamSpec("P")
 T = TypeVar("T")
+A = TypeVar("A", bound=Callable[..., Awaitable[Any]])
 
 
 class UnavailableTokensError(Exception):
@@ -181,8 +182,8 @@ def alimit(
         model_name: str,
         input_cost_fn: Callable[..., Numeric],
         response_cost_fn: Callable[..., Numeric],
-    ) -> Callable[[Callable[P, T]], Callable[P, T]]:
-        def rate_limit_decorator(fn: Callable[P, T]) -> Callable[P, T]:
+    ) -> Callable[[A], A]:
+        def rate_limit_decorator(fn: A) -> A:
             @wraps(fn)
             async def wrapper(*args: Any, **kwargs: Any) -> T:
                 key = self.key(model_name)
@@ -193,6 +194,6 @@ async def wrapper(*args: Any, **kwargs: Any) -> T:
                 self._store.spend_rate_limits(key, {"tokens": response_cost_fn(result)})
                 return result
 
-            return wrapper
+            return cast(A, wrapper)
 
         return rate_limit_decorator