# LLM Function Module

`LLMFunctionModule` is a module used for executing LLM function calls.

Function calls can be seen as a formatting wrapper provided by LLM (currently only supports OpenAI series models), allowing parameters to be input via JSON, and outputting a serial JSON as we defined in `function_parameters`.

Reference:

* <https://www.promptingguide.ai/applications/function_calling>
* <https://platform.openai.com/docs/api-reference/chat/create>

The module input can be specified by each parameter in the config.

The output of the module is a JSON object, which includes the LLM return results and will be automatically output to the state machine output in the form of key-value pairs.

`LLMFunctionConfig` is similar to `LLMConfig`. It only differs by:

* the lack of `output_name`
* three fields starting with `function_`, which are vital for the LLMFunctionModule as they control the function behavior. They will be placed in the tools field of the LLM Request Body.

`LLMFunctionConfig`

| Field's Name          | JSON Type (Required/Optional)   | Description                                                    | Example                                                                            |
| --------------------- | ------------------------------- | -------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
| function\_name        | string (Required)               | Specifies the name of the function in LLMFunctionConfig.       | 'get\_current\_weather'                                                            |
| function\_description | string (Required)               | Provides a description of the function in LLMFunctionConfig.   | 'Get the current weather in a given location'                                      |
| function\_parameters  | FunctionParameter\[] (Required) | Specifies the parameters of the function in LLMFunctionConfig. | \[{name: 'city', type: 'string', description: 'The city, e.g. San Francisco, CA'}] |

`FunctionParameter`

| Field's Name | JSON Type (Required/Optional) | Description                                                            | Example                            |
| ------------ | ----------------------------- | ---------------------------------------------------------------------- | ---------------------------------- |
| name         | string (Required)             | Specifies the name of the function parameter in FunctionParameter.     | 'city'                             |
| type         | string (Required)             | Specifies the type of the function parameter in FunctionParameter.     | 'list', 'string' or 'number'       |
| description  | string (Required)             | Provides a description of the function parameter in FunctionParameter. | 'The city, e.g. San Francisco, CA' |