enable_structured_output: Enable Structured Output (Provider-Agnostic)

In LLMR: Interface for Large Language Model APIs in R

Enable Structured Output (Provider-Agnostic)

Description

Turn on structured output for a model configuration. Supports OpenAI-compatible providers (OpenAI, Groq, Together, x.ai, DeepSeek, Xiaomi, Alibaba (Qwen), Zhipu, Moonshot), Anthropic, and Gemini.

Usage

enable_structured_output(
  config,
  schema = NULL,
  name = "llmr_schema",
  method = c("auto", "json_mode", "tool_call"),
  strict = TRUE
)

Arguments

config	An llm_config object.
schema	A named list representing a JSON Schema. If NULL, OpenAI-compatible providers enforce a JSON object; Gemini switches to JSON mime type; Anthropic only injects a tool when a schema is supplied.
name	Character. Schema/tool name for providers requiring one. Default "llmr_schema".
method	One of c("auto","json_mode","tool_call"). "auto" chooses the best per provider. You rarely need to change this.
strict	Logical. Request strict validation when supported (OpenAI-compatible). Strict mode has formal requirements of its own: every object must set additionalProperties: false and list all its properties as required. LLMR fills those in automatically where your schema leaves them unspecified (your explicit settings are never overridden); pass strict = FALSE to send the schema verbatim.

Value

Modified llm_config.

Server-side enforcement by provider

OpenAI, Groq, Together, x.ai, and Ollama accept a strict json_schema response format. DeepSeek, Alibaba (Qwen), Zhipu, Moonshot, and Xiaomi accept only JSON-object mode; for them the supplied schema drives local parsing and validation, so the prompt itself should describe the desired fields. Anthropic enforcement runs through a forced tool call; Gemini through responseJsonSchema.

Gemini

A supplied schema is sent as responseJsonSchema (standard JSON Schema, supported by Gemini 2.5+ models) together with the JSON mime type. For an older model that rejects it, set gemini_enable_response_schema = FALSE in the config to fall back to JSON-mime-type-only mode (the reply is still parsed and can be validated locally).

When to use tags instead

For tasks where strict JSON schema is unnecessary or unsupported, consider llm_mutate() with .tags or llm_mutate_tags() for soft structured output.

See Also

disable_structured_output(), llm_parse_structured(), llm_parse_structured_col(), llm_mutate_structured(), llm_mutate_tags()

LLMR documentation built on July 11, 2026, 1:06 a.m.