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                *   [String output parser](/v0.1/docs/modules/model_io/output_parsers/types/string/)
                *   [HTTP Response Output Parser](/v0.1/docs/modules/model_io/output_parsers/types/http_response/)
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*   [](/v0.1/)
*   [Modules](/v0.1/docs/modules/)
*   [Model I/O](/v0.1/docs/modules/model_io/)
*   [Output Parsers](/v0.1/docs/modules/model_io/output_parsers/)
*   [Output Parser Types](/v0.1/docs/modules/model_io/output_parsers/types/)
*   HTTP Response Output Parser

HTTP Response Output Parser
===========================

The HTTP Response output parser allows you to stream LLM output properly formatted bytes a web [HTTP response](https://developer.mozilla.org/en-US/docs/Web/API/Response):

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";import { HttpResponseOutputParser } from "langchain/output_parsers";const handler = async () => {  const parser = new HttpResponseOutputParser();  const model = new ChatOpenAI({ temperature: 0 });  const stream = await model.pipe(parser).stream("Hello there!");  const httpResponse = new Response(stream, {    headers: {      "Content-Type": "text/plain; charset=utf-8",    },  });  return httpResponse;};await handler();

#### API Reference:

*   [ChatOpenAI](https://api.js.langchain.com/classes/langchain_openai.ChatOpenAI.html) from `@langchain/openai`
*   [HttpResponseOutputParser](https://api.js.langchain.com/classes/langchain_output_parsers.HttpResponseOutputParser.html) from `langchain/output_parsers`

You can also stream back chunks as an [event stream](https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events):

    import { ChatOpenAI } from "@langchain/openai";import { HttpResponseOutputParser } from "langchain/output_parsers";const handler = async () => {  const parser = new HttpResponseOutputParser({    contentType: "text/event-stream",  });  const model = new ChatOpenAI({ temperature: 0 });  // Values are stringified to avoid dealing with newlines and should  // be parsed with `JSON.parse()` when consuming.  const stream = await model.pipe(parser).stream("Hello there!");  const httpResponse = new Response(stream, {    headers: {      "Content-Type": "text/event-stream",    },  });  return httpResponse;};await handler();

#### API Reference:

*   [ChatOpenAI](https://api.js.langchain.com/classes/langchain_openai.ChatOpenAI.html) from `@langchain/openai`
*   [HttpResponseOutputParser](https://api.js.langchain.com/classes/langchain_output_parsers.HttpResponseOutputParser.html) from `langchain/output_parsers`

Or pass a custom output parser to internally parse chunks for e.g. streaming function outputs:

    import { ChatOpenAI } from "@langchain/openai";import {  HttpResponseOutputParser,  JsonOutputFunctionsParser,} from "langchain/output_parsers";const handler = async () => {  const parser = new HttpResponseOutputParser({    contentType: "text/event-stream",    outputParser: new JsonOutputFunctionsParser({ diff: true }),  });  const model = new ChatOpenAI({ temperature: 0 }).bind({    functions: [      {        name: "get_current_weather",        description: "Get the current weather in a given location",        parameters: {          type: "object",          properties: {            location: {              type: "string",              description: "The city and state, e.g. San Francisco, CA",            },            unit: { type: "string", enum: ["celsius", "fahrenheit"] },          },          required: ["location"],        },      },    ],    // You can set the `function_call` arg to force the model to use a function    function_call: {      name: "get_current_weather",    },  });  const stream = await model.pipe(parser).stream("Hello there!");  const httpResponse = new Response(stream, {    headers: {      "Content-Type": "text/event-stream",    },  });  return httpResponse;};await handler();

#### API Reference:

*   [ChatOpenAI](https://api.js.langchain.com/classes/langchain_openai.ChatOpenAI.html) from `@langchain/openai`
*   [HttpResponseOutputParser](https://api.js.langchain.com/classes/langchain_output_parsers.HttpResponseOutputParser.html) from `langchain/output_parsers`
*   [JsonOutputFunctionsParser](https://api.js.langchain.com/classes/langchain_output_parsers.JsonOutputFunctionsParser.html) from `langchain/output_parsers`

* * *

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