Programmatic Workflows (RunWorkflow)

Use RunWorkflow when a deterministic pipeline should orchestrate multiple subagents — fan-out research then synthesize, classify then act per item, generate then verify. Prefer it over issuing many Task calls yourself when the dispatches are data-driven (one per ticker, per filing, per finding). Do NOT use it for a single subagent (use Task) or for code that dispatches nothing (use ExecuteCode).

The script

You write JavaScript (ES2020). It executes server-side: the script itself cannot touch the workspace filesystem — the subagents it dispatches can. The script must declare a pure object literal first:

export const meta = { name: 'ticker-briefs', description: 'Fan out research, synthesize' }

name (letters, digits, -, _) and description are required; no variables or function calls inside the literal. The rest of the body is free-form async JS — top-level await and return both work, and the return value (JSON-serializable) becomes the run result. Return a synthesis rather than the raw children: a large result is clipped for display, and a clipped object is unparseable.

Built-ins

• await agent(prompt, opts?) — dispatch one subagent, resolve to its result text. The child starts blank: it sees nothing of this conversation, of the script, or of its sibling children, so the prompt must carry everything it needs — and its final text is the whole of what comes back. opts: agentType (default 'general-purpose'; same types as Task), label (display name), phase (progress group), schema (JSON Schema — the child answers as matching JSON and the resolved value is the parsed object, or null if it cannot).
• await pipeline(items, ...stages) — the default for multi-stage work. Each item flows through every stage independently, with NO barrier between stages: item A can be in stage 3 while item B is still in stage 1, so the run costs the slowest single chain rather than the sum of each stage's slowest item. Each stage receives (prevResult, originalItem, index); a throwing stage nulls that item and skips its remaining stages.
• await parallel(thunks) — run an array of () => Promise thunks concurrently, resolving to results in order; already-started promises (parallel([agent(...), ...])) work too. Use it for a single fan-out, or where the next step genuinely needs the whole set at once — dedup across all results, an early exit when the count is zero, one child weighing the others. Needing to map/filter between stages is not such a case: do that inside a pipeline stage.
• phase(title) / log(message) — progress markers streamed live to the user.
• args — the params value passed to RunWorkflow, verbatim.

Failure semantics:

• A failed slot resolves to null — the child errored, timed out, or the run had already spent its dispatch cap. Read null as "no result from this call", never as "the child ran and found nothing": a run whose children all return null has produced nothing, so check before reporting success and write the synthesis to survive partial results.
• A call your script got wrong — unknown agentType, an oversized prompt or schema — is a bug rather than a failure, and so is an ordinary typo or a wrong shape handed to a helper. Those end the run with the real error, in a parallel slot or a pipeline stage too, instead of leaving you a silent list of nulls to explain.

Limits (defaults): 64 dispatches per run, 8 running at once — extra agent() calls queue, so fan out freely — and 30 minutes per child.

Examples

Single fan-out — one dispatch per item, synthesized in JS:

export const meta = { name: 'ticker-briefs', description: 'Research each ticker, then synthesize' }

phase('Research')
const briefSchema = {
  type: 'object',
  properties: { summary: { type: 'string' }, risks: { type: 'array', items: { type: 'string' } } },
  required: ['summary'],
}
const results = await parallel(args.tickers.map((t) => () =>
  agent(`Research ${t}: fundamentals, recent news, key risks.`, { agentType: 'research', label: t, schema: briefSchema })))

phase('Synthesize')
const briefs = {}
const failed = []
results.forEach((r, i) => { if (r !== null) briefs[args.tickers[i]] = r; else failed.push(args.tickers[i]) })
log(`${Object.keys(briefs).length} briefs, ${failed.length} failed`)
return { briefs, failed }

Two stages per item, no barrier — a slow filing never holds up the others:

export const meta = { name: 'filing-risk-sweep', description: 'Summarize each filing, then stress-test it' }

const reviewed = await pipeline(
  args.tickers,
  (ticker) => agent(`Summarize ${ticker}'s latest 10-Q: segment results, guidance changes, new risk language.`,
    { agentType: 'research', label: ticker, phase: 'Read' }),
  (summary, ticker) => summary === null ? null : agent(
    `Challenge this ${ticker} summary — what does it overstate, omit, or take on trust?\n\n${summary}`,
    { agentType: 'equity-analyst', label: `${ticker} review`, phase: 'Challenge' }),
)

log(`${reviewed.filter((r) => r !== null).length}/${args.tickers.length} reviewed`)
return Object.fromEntries(args.tickers.map((t, i) => [t, reviewed[i]]))

Set phase per dispatch rather than calling phase() inside a stage: items run concurrently, so a global marker set mid-pipeline reflects whichever item reached it last. Guard each stage on its input, and test against null rather than truthiness — 0, false and "" are answers a child succeeded with, and summary && agent(...) would drop them as failures.

Saved workflows

• Workflows live at .agents/workflows/<name>.js — the file is the whole script, meta included, and meta.name must equal <name>. List what is already there with ls .agents/workflows/; run one with RunWorkflow(workflow="<name>", params={...}).
• Write .agents/workflows/<name>.js to save a workflow you expect to run again; it stays available across threads.

Running

RunWorkflow(script=..., params={...}) (or script_path=..., or workflow="<name>") returns a task id immediately and runs in the background — continue other work, then poll TaskOutput(task_id="...") for progress or the final result (add timeout=120 to block). Each dispatched child is a real background task: drill into a truncated result with TaskOutput(task_id="<child task_id>"). Run artifacts (per-child records, result.json) land under .agents/threads/<thread>/workflows/<run-id>/.