openlimit-lite

Forked from https://github.com/shobrook/openlimit. Maintaining for our own use, stripping down to remove Redis dependencies.

A simple tool for maximizing usage of the OpenAI API without hitting the rate limit.

• Handles both request and token limits
• Precisely (to the millisecond) enforces rate limits with one line of code
• Handles synchronous and asynchronous requests

Implements the generic cell rate algorithm, a variant of the leaky bucket pattern.

Usage

Define a rate limit

First, define your rate limits for the OpenAI model you're using. For example:

from openlimit_lite import ChatRateLimiter

rate_limiter = ChatRateLimiter(request_limit=200, token_limit=40000)

This sets a rate limit for a chat completion model (e.g. gpt-4, gpt-3.5-turbo). openlimit offers different rate limiter objects for different OpenAI models, all with the same parameters: request_limit and token_limit. Both limits are measured per-minute and may vary depending on the user.

Apply the rate limit

To apply the rate limit, add a with statement to your API calls:

chat_params = {
    "model": "gpt-4",
    "messages": [{"role": "user", "content": "Hello!"}]
}

with rate_limiter.limit(**chat_params):
    response = openai.ChatCompletion.create(**chat_params)

Ensure that rate_limiter.limit receives the same parameters as the actual API call. This is important for calculating expected token usage.

Alternatively, you can decorate functions that make API calls, as long as the decorated function receives the same parameters as the API call:

@rate_limiter.is_limited()
def call_openai(**chat_params):
    response = openai.ChatCompletion.create(**chat_params)
    return response

Asynchronous requests

Rate limits can be enforced for asynchronous requests too:

chat_params = {
    "model": "gpt-4",
    "messages": [{"role": "user", "content": "Hello!"}]
}

async with rate_limiter.limit(**chat_params):
    response = await openai.ChatCompletion.acreate(**chat_params)

Token counting

Aside from rate limiting, openlimit also provides methods for counting tokens consumed by requests.

Chat requests

To count the maximum number of tokens that could be consumed by a chat request (e.g. gpt-3.5-turbo, gpt-4), pass the request arguments into the following function:

from openlimit.utilities import num_tokens_consumed_by_chat_request

request_args = {
    "model": "gpt-3.5-turbo",
    "messages": [{"role": "...", "content": "..."}, ...],
    "max_tokens": 15,
    "n": 1
}
num_tokens = num_tokens_consumed_by_chat_requests(**request_args)

Completion requests

Similar to chat requests, to count tokens for completion requests (e.g. text-davinci-003), pass the request arguments into the following function:

from openlimit.utilities import num_tokens_consumed_by_completion_request

request_args = {
    "model": "text-davinci-003",
    "prompt": "...",
    "max_tokens": 15,
    "n": 1
}
num_tokens = num_tokens_consumed_by_completion_request(**request_args)

Embedding requests

For embedding requests (e.g. text-embedding-ada-002), pass the request arguments into the following function:

from openlimit.utilities import num_tokens_consumed_by_embedding_request

request_args = {
    "model": "text-embedding-ada-002",
    "input": "..."
}
num_tokens = num_tokens_consumed_by_embedding_request(**request_args)