[Home](./index.md) > [kibana-plugin-plugins-expressions-public](./kibana-plugin-plugins-expressions-public.md) > [ExpressionFunction](./kibana-plugin-plugins-expressions-public.expressionfunction.md) ## ExpressionFunction class Signature: ```typescript export declare class ExpressionFunction ``` ## Constructors | Constructor | Modifiers | Description | | --- | --- | --- | | [(constructor)(functionDefinition)](./kibana-plugin-plugins-expressions-public.expressionfunction._constructor_.md) | | Constructs a new instance of the ExpressionFunction class | ## Properties | Property | Modifiers | Type | Description | | --- | --- | --- | --- | | [accepts](./kibana-plugin-plugins-expressions-public.expressionfunction.accepts.md) | | (type: string) => boolean | | | [aliases](./kibana-plugin-plugins-expressions-public.expressionfunction.aliases.md) | | string[] | Aliases that can be used instead of name. | | [args](./kibana-plugin-plugins-expressions-public.expressionfunction.args.md) | | Record<string, ExpressionFunctionParameter> | Specification of expression function parameters. | | [fn](./kibana-plugin-plugins-expressions-public.expressionfunction.fn.md) | | (input: ExpressionValue, params: Record<string, any>, handlers: object) => ExpressionValue | Function to run function (context, args) | | [help](./kibana-plugin-plugins-expressions-public.expressionfunction.help.md) | | string | A short help text. | | [inputTypes](./kibana-plugin-plugins-expressions-public.expressionfunction.inputtypes.md) | | string[] | undefined | Type of inputs that this function supports. | | [name](./kibana-plugin-plugins-expressions-public.expressionfunction.name.md) | | string | Name of function | | [type](./kibana-plugin-plugins-expressions-public.expressionfunction.type.md) | | string | Return type of function. This SHOULD be supplied. We use it for UI and autocomplete hinting. We may also use it for optimizations in the future. |