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# Structured Output with OpenAI functions

:::tip Compatibility
Must be used with an [OpenAI functions](https://platform.openai.com/docs/guides/gpt/function-calling) model.
:::

This chain leverages OpenAI functions to output objects that match a given format for any given prompt.
It converts input schema into an OpenAI function, then forces OpenAI to call that function to return a response in the correct format.

You can use it where you would use a chain with a [`StructuredOutputParser`](/docs/modules/model_io/output_parsers) without any special
instructions stuffed into the prompt. It will also more reliably output structured results with higher `temperature` values, making it better suited
for more creative applications.

**Note:** The outermost layer of the input schema must be an object.

## Usage

### Format Text into Structured Data

import FormatExample from "@examples/chains/openai_functions_structured_format.ts";

<CodeBlock language="typescript">{FormatExample}</CodeBlock>

### Generate a Database Record

import GenerateExample from "@examples/chains/openai_functions_structured_generate.ts";

<CodeBlock language="typescript">{GenerateExample}</CodeBlock>

### Customization

This chain takes all the same arguments as a standard [`LLMChain`](/docs/modules/chains/foundational/llm_chain) minus an `outputParser`. It will also be created with a default model set to `gpt-3.5-turbo-0613`,
but you can pass an options parameter into the input parameters with a pre-created `ChatOpenAI` instance as `llm`.