llm_fn_structured: Vectorized structured-output LLM

In LLMR: Interface for Large Language Model APIs in R

Vectorized structured-output LLM

Description

Schema-first variant of llm_fn(). It enables structured output on the config, calls the model via call_llm_broadcast(), parses JSON, and optionally validates.

Usage

llm_fn_structured(
  x,
  prompt,
  .config,
  .system_prompt = NULL,
  ...,
  .schema = NULL,
  .fields = NULL,
  .local_only = FALSE,
  .validate_local = TRUE,
  .rows_per_prompt = 1L,
  .rowpack_payload = c("user", "system"),
  .rowpack_recovery = c("halve_recursive", "halve_once", "singletons", "retry_same",
    "none")
)

Arguments

x	A character vector or a data.frame/tibble.
prompt	A glue template string. With a data-frame you may reference columns ({col}); with a vector the placeholder is {x}.
.config	An llm_config object.
.system_prompt	Optional system message (character scalar).
...	Passed unchanged to call_llm_broadcast() (e.g. tries, progress, verbose).
.schema	Optional JSON Schema list; if NULL, only JSON object is enforced.
.fields	Optional fields to hoist from parsed JSON (supports nested paths).
.local_only	If TRUE, do not send schema to the provider (parse/validate locally).
.validate_local	If TRUE and .schema provided, validate locally.
.rows_per_prompt	Integer scalar, or Inf. Number of input elements packed into a single generative request. The default, 1, sends one request per element (the historical behaviour). When greater than 1, elements are grouped and transmitted in one call wrapped in numbered ⁠<row_1>...</row_1>⁠ tags (see Row batching below); Inf sends all elements in a single call. Ignored for embedding configurations, which use get_batched_embeddings() instead.
.rowpack_payload	One of c("user","system"). Channel to which the ⁠<row_i>⁠ data block is appended when batching. The imperative instruction is always placed in the system message; this argument controls only where the data goes. The default, "user", keeps a static system prompt cacheable.
.rowpack_recovery	How to handle rows that a batched call leaves unresolved (dropped, malformed, or truncated). One of: "halve_recursive" (default) re-issue the unresolved rows at half the batch size, recursing down to single rows. "halve_once" re-issue at half the batch size exactly once, then give up on any still-unresolved rows. "singletons" re-issue each unresolved row on its own. "retry_same" re-issue the failed batch once at the same size. "none" do not recover; unresolved rows are returned as NA. Recovery is bounded by an internal call budget so it always terminates.

Value

A tibble: the call_llm_broadcast() diagnostics plus the parsed structured columns (structured_ok, structured_data, one column per hoisted field, and structured_valid/structured_error when .schema is validated locally).

See Also

llm_fn(), llm_mutate_structured(), enable_structured_output(), llm_parse_structured_col()

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