Build a Custom Multi-Agent Team (Supervisor Style)

Build a supervisor-routed multi-agent workflow, similar to LangGraph team orchestration. The supervisor chooses the next worker by setting `state$next` to one of the worker names or `FINISH`.

Usage

build_custom_multi_agent(
  supervisor,
  workers,
  finish_token = "FINISH",
  max_turns = 10L,
  allow_repeat = FALSE,
  worker_error_policy = c("return_to_supervisor", "stop"),
  default_state = list(),
  checkpointer = NULL,
  output = c("agent", "mermaid", "both"),
  direction = c("TD", "LR"),
  subgraphs = NULL,
  style = TRUE
)

Arguments

supervisor

Function that accepts `state` and returns: - worker name (character scalar), or - list with `next`, optionally additional updates.

workers

Named list of workers. Each worker can be: - a function that accepts `state` and returns a named list of updates, or - a compiled custom-agent object with a callable `$run` function (for example from [build_custom_agent()] with `output = "both"` or [compile_graph()]).

finish_token

Character label used by the supervisor to terminate.

max_turns

Maximum worker turns before forcing finish.

allow_repeat

Logical; allow the same worker twice in a row.

worker_error_policy

`"return_to_supervisor"` (default) or `"stop"`.

default_state

Optional defaults merged into incoming `state`.

checkpointer

Optional callback `function(state, current_node)`.

output

Output mode: - `"agent"` (default): return runnable agent, - `"mermaid"`: return Mermaid text, - `"both"`: return list with `run`, `graph`, and `mermaid`.

direction

Mermaid direction when `output` includes Mermaid.

subgraphs

Optional Mermaid subgraph groups. If `NULL`, defaults to `list(Supervisor = "supervisor", Workers = names(workers))`.

style

Logical; include default Mermaid class styling.

Value

- If `output = "agent"`: runnable function(state). - If `output = "mermaid"`: Mermaid text. - If `output = "both"`: list with `run`, `graph`, and `mermaid`.

Examples

if (FALSE) { # \dontrun{
supervisor_fn <- function(state) {
  if (is.null(state$turn) || state$turn == 0) "Researcher" else "FINISH"
}

workers <- list(
  Researcher = function(state) {
    list(result = "Research complete")
  },
  Writer = function(state) {
    list(result = "Draft complete")
  }
)

team <- build_custom_multi_agent(
  supervisor = supervisor_fn,
  workers = workers,
  output = "both"
)

cat(team$mermaid)
team$run(list())
} # }