Type: Type definitions for function calling and structured data...

In ellmer: Chat with Large Language Models

Type definitions for function calling and structured data extraction.

Description

These S7 classes are provided for use by package devlopers who are extending ellmer. In every day use, use type_boolean() and friends.

Usage

TypeBasic(description = NULL, required = TRUE, type = stop("Required"))

TypeEnum(description = NULL, required = TRUE, values = character(0))

TypeArray(description = NULL, required = TRUE, items = Type())

TypeJsonSchema(description = NULL, required = TRUE, json = list())

TypeIgnore(description = NULL, required = TRUE)

TypeObject(
  description = NULL,
  required = TRUE,
  properties = list(),
  additional_properties = FALSE
)

Arguments

description	The purpose of the component. This is used by the LLM to determine what values to pass to the tool or what values to extract in the structured data, so the more detail that you can provide here, the better.
required	Is the component or argument required? In type descriptions for structured data, if required = FALSE and the component does not exist in the data, the LLM may hallucinate a value. Only applies when the element is nested inside of a type_object(). In tool definitions, required = TRUE signals that the LLM should always provide a value. Arguments with required = FALSE should have a default value in the tool function's definition. If the LLM does not provide a value, the default value will be used.
type	Basic type name. Must be one of boolean, integer, number, or string.
values	Character vector of permitted values.
items	The type of the array items. Can be created by any of the type_ function.
json	A JSON schema object as a list.
properties	Named list of properties stored inside the object. Each element should be an S7 Type object.'
additional_properties	Can the object have arbitrary additional properties that are not explicitly listed? Only supported by Claude.

Value

S7 objects inheriting from Type

Examples

TypeBasic(type = "boolean")
TypeArray(items = TypeBasic(type = "boolean"))

ellmer documentation built on July 14, 2026, 1:07 a.m.