!function(){function t(t){document.documentElement.setAttribute("data-theme",t)}var e=function(){var t=null;try{t=new URLSearchParams(window.location.search).get("docusaurus-theme")}catch(t){}return t}()||function(){var t=null;try{t=localStorage.getItem("theme")}catch(t){}return t}();t(null!==e?e:"light")}(),document.documentElement.setAttribute("data-announcement-bar-initially-dismissed",function(){try{return"true"===localStorage.getItem("docusaurus.announcement.dismiss")}catch(t){}return!1}())

[Skip to main content](#__docusaurus_skipToContent_fallback)

LangChain v0.2 is coming soon! Preview the new docs [here](/v0.2/docs/introduction/).

[

![🦜️🔗 Langchain](/v0.1/img/brand/wordmark.png)![🦜️🔗 Langchain](/v0.1/img/brand/wordmark-dark.png)

](/v0.1/)[Docs](/v0.1/docs/get_started/introduction/)[Use cases](/v0.1/docs/use_cases/)[Integrations](/v0.1/docs/integrations/platforms/)[API Reference](https://api.js.langchain.com)

[More](#)

*   [People](/v0.1/docs/people/)
*   [Community](/v0.1/docs/community/)
*   [Tutorials](/v0.1/docs/additional_resources/tutorials/)
*   [Contributing](/v0.1/docs/contributing/)

[v0.1](#)

*   [v0.2](https://js.langchain.com/v0.2/docs/introduction)
*   [v0.1](/v0.1/docs/get_started/introduction/)

[🦜🔗](#)

*   [LangSmith](https://smith.langchain.com)
*   [LangSmith Docs](https://docs.smith.langchain.com)
*   [LangChain Hub](https://smith.langchain.com/hub)
*   [LangServe](https://github.com/langchain-ai/langserve)
*   [Python Docs](https://python.langchain.com/)

[Chat](https://chatjs.langchain.com)[](https://github.com/langchain-ai/langchainjs)

Search

*   [Get started](/v0.1/docs/get_started/)
    
    *   [Introduction](/v0.1/docs/get_started/introduction/)
    *   [Installation](/v0.1/docs/get_started/installation/)
    *   [Quickstart](/v0.1/docs/get_started/quickstart/)
*   [LangChain Expression Language](/v0.1/docs/expression_language/)
    
    *   [Get started](/v0.1/docs/expression_language/get_started/)
    *   [Why use LCEL?](/v0.1/docs/expression_language/why/)
    *   [Interface](/v0.1/docs/expression_language/interface/)
    *   [Streaming](/v0.1/docs/expression_language/streaming/)
    *   [How to](/v0.1/docs/expression_language/how_to/routing/)
        
    *   [Cookbook](/v0.1/docs/expression_language/cookbook/)
        
    *   [LangChain Expression Language (LCEL)](/v0.1/docs/expression_language/)
*   [Modules](/v0.1/docs/modules/)
    
    *   [Model I/O](/v0.1/docs/modules/model_io/)
        
        *   [Quickstart](/v0.1/docs/modules/model_io/quick_start/)
        *   [Concepts](/v0.1/docs/modules/model_io/concepts/)
        *   [Prompts](/v0.1/docs/modules/model_io/prompts/)
            
        *   [LLMs](/v0.1/docs/modules/model_io/llms/)
            
        *   [Chat Models](/v0.1/docs/modules/model_io/chat/)
            
            *   [Quick Start](/v0.1/docs/modules/model_io/chat/quick_start/)
            *   [Streaming](/v0.1/docs/modules/model_io/chat/streaming/)
            *   [Caching](/v0.1/docs/modules/model_io/chat/caching/)
            *   [Custom chat models](/v0.1/docs/modules/model_io/chat/custom_chat/)
            *   [Tracking token usage](/v0.1/docs/modules/model_io/chat/token_usage_tracking/)
            *   [Cancelling requests](/v0.1/docs/modules/model_io/chat/cancelling_requests/)
            *   [Dealing with API Errors](/v0.1/docs/modules/model_io/chat/dealing_with_api_errors/)
            *   [Dealing with rate limits](/v0.1/docs/modules/model_io/chat/dealing_with_rate_limits/)
            *   [Tool/function calling](/v0.1/docs/modules/model_io/chat/function_calling/)
            *   [Response metadata](/v0.1/docs/modules/model_io/chat/response_metadata/)
            *   [Subscribing to events](/v0.1/docs/modules/model_io/chat/subscribing_events/)
            *   [Adding a timeout](/v0.1/docs/modules/model_io/chat/timeouts/)
        *   [Model I/O](/v0.1/docs/modules/model_io/)
        *   [Output Parsers](/v0.1/docs/modules/model_io/output_parsers/)
            
    *   [Retrieval](/v0.1/docs/modules/data_connection/)
        
    *   [Chains](/v0.1/docs/modules/chains/)
    *   [Agents](/v0.1/docs/modules/agents/)
        
    *   [More](/v0.1/docs/modules/memory/)
        
*   [Security](/v0.1/docs/security/)
*   [Guides](/v0.1/docs/guides/)
    
*   [Ecosystem](/v0.1/docs/ecosystem/)
    
*   [LangGraph](/v0.1/docs/langgraph/)
*   * * *
    

*   [](/v0.1/)
*   [Modules](/v0.1/docs/modules/)
*   [Model I/O](/v0.1/docs/modules/model_io/)
*   [Chat Models](/v0.1/docs/modules/model_io/chat/)
*   Dealing with rate limits

Dealing with rate limits
========================

Some providers have rate limits. If you exceed the rate limit, you'll get an error. To help you deal with this, LangChain provides a `maxConcurrency` option when instantiating a Chat Model. This option allows you to specify the maximum number of concurrent requests you want to make to the provider. If you exceed this number, LangChain will automatically queue up your requests to be sent as previous requests complete.

For example, if you set `maxConcurrency: 5`, then LangChain will only send 5 requests to the provider at a time. If you send 10 requests, the first 5 will be sent immediately, and the next 5 will be queued up. Once one of the first 5 requests completes, the next request in the queue will be sent.

To use this feature, simply pass `maxConcurrency: <number>` when you instantiate the LLM. For example:

tip

See [this section for general instructions on installing integration packages](/v0.1/docs/get_started/installation/#installing-integration-packages).

*   npm
*   Yarn
*   pnpm

    npm install @langchain/openai

    yarn add @langchain/openai

    pnpm add @langchain/openai

    import { ChatOpenAI } from "@langchain/openai";const model = new ChatOpenAI({ maxConcurrency: 5 });

* * *

#### Help us out by providing feedback on this documentation page:

[

Previous

Dealing with API Errors

](/v0.1/docs/modules/model_io/chat/dealing_with_api_errors/)[

Next

Tool/function calling

](/v0.1/docs/modules/model_io/chat/function_calling/)

Community

*   [Discord](https://discord.gg/cU2adEyC7w)
*   [Twitter](https://twitter.com/LangChainAI)

GitHub

*   [Python](https://github.com/langchain-ai/langchain)
*   [JS/TS](https://github.com/langchain-ai/langchainjs)

More

*   [Homepage](https://langchain.com)
*   [Blog](https://blog.langchain.dev)

Copyright © 2024 LangChain, Inc.