workflow-authoring

# Workflow authoring reference

A workflow structures work across many agents — to be comprehensive (decompose and cover in parallel), to be confident (independent perspectives and adversarial checks before committing), or to take on scale one context can't hold (migrations, audits, broad sweeps). The script is where you encode that structure: what fans out, what verifies, what synthesizes.

When you do call it, the right move is often **hybrid**: scout inline first (list the files, find the channels, scope the diff) to discover the work-list, then call Workflow to pipeline over it. You don't need to know the shape before the *task* — only before the *orchestration step*.

Common single-phase workflows you can chain across turns:
- **Understand** — parallel readers over relevant subsystems → structured map
- **Design** — judge panel of N independent approaches → scored synthesis
- **Review** — dimensions → find → adversarially verify (the review-changes example)
- **Research** — multi-modal sweep → deep-read → synthesize
- **Migrate** — discover sites → transform each (worktree isolation) → verify

For larger work, run several in sequence — read each result before deciding the next phase. You stay in the loop; each workflow is one well-scoped fan-out.

**Ultracode.** When a system-reminder confirms ultracode is on, that opt-in is standing: author and run a workflow for every substantive task by default. The goal is the most exhaustive, correct answer you can produce — token cost is not a constraint. For multi-phase work (understand → design → implement → review), that often means several workflows in sequence — one per phase — so you stay in the loop between them. The quality patterns below (adversarial verify, multi-modal sweep, completeness critic, loop-until-dry) are the tools; pick what fits the task. Lean toward orchestrating with workflows and adversarially verifying your findings — unless the work is trivial or already verified. Solo only on conversational turns or trivial mechanical edits. When a reminder says ultracode is off, revert to the opt-in rule in the Workflow tool description.

Pass the script inline via `script` — do not Write it to a file first. Every invocation automatically persists its script to a file under the session directory and returns the path in the tool result. To iterate on a workflow, edit that file with Write/Edit and re-invoke Workflow with `{scriptPath: "<path>"}` instead of resending the full script.

Every script must begin with `export const meta = {...}`:
  export const meta = {
    name: 'find-flaky-tests',
    description: 'Find flaky tests and propose fixes',   // one-line, shown in permission dialog
    phases: [                                            // one entry per phase() call
      { title: 'Scan', detail: 'grep test logs for retries' },
      { title: 'Fix', detail: 'one agent per flaky test' },
    ],
  }
  // script body starts here — use agent()/parallel()/pipeline()/phase()/log()
  phase('Scan')
  const flaky = await agent('grep CI logs for retry markers', {schema: FLAKY_SCHEMA})
  ...

The `meta` object must be a PURE LITERAL — no variables, function calls, spreads, or template interpolation. Required fields: `name`, `description`. Optional: `whenToUse` (shown in the workflow list), `phases`. Use the SAME phase titles in meta.phases as in phase() calls — titles are matched exactly; a phase() call with no matching meta entry just gets its own progress group. Add `model` to a phase entry when that phase uses a specific model override.

Script body hooks:
- agent(prompt: string, opts?: {label?: string, phase?: string, schema?: object, model?: string, effort?: string, isolation?: 'worktree', agentType?: string}): Promise<any> — spawn a subagent. Without schema, returns its final text as a string. With schema (a JSON Schema), the subagent is forced to call a StructuredOutput tool and agent() returns the validated object — no parsing needed. Returns null if the user skips the agent mid-run or the subagent dies on a terminal API error after retries (filter with .filter(Boolean)). opts.label overrides the display label. opts.phase explicitly assigns this agent to a progress group (use this inside pipeline()/parallel() stages to avoid races on the global phase() state — same phase string → same group box). opts.model overrides the model for this agent call. Default to omitting it — the agent inherits the main-loop model (the resolved session model), which is almost always correct. Only set it when you're highly confident a different tier fits the task; when unsure, omit. opts.effort overrides the reasoning effort for this agent call ('low' | 'medium' | 'high' | 'xhigh' | 'max') — omit to inherit the session effort; use 'low' for cheap mechanical stages and higher tiers only for the hardest verify/judge stages. opts.isolation: 'worktree' runs the agent in a fresh git worktree — EXPENSIVE (~200-500ms setup + disk per agent), use ONLY when agents mutate files in parallel and would otherwise conflict; the worktree is auto-removed if unchanged. opts.agentType uses a custom subagent type (e.g. 'general-purpose', 'code-reviewer') instead of the default workflow subagent — resolved from the same registry as the Agent tool; composes with schema (the custom agent's system prompt gets a StructuredOutput instruction appended).
- pipeline(items, stage1, stage2, ...): Promise<any[]> — run each item through all stages independently, NO barrier between stages. Item A can be in stage 3 while item B is still in stage 1. This is the DEFAULT for multi-stage work. Wall-clock = slowest single-item chain, not sum-of-slowest-per-stage. Every stage callback receives (prevResult, originalItem, index) — use originalItem/index in later stages to label work without threading context through stage 1's return value. A stage that throws drops that item to `null` and skips its remaining stages.
- parallel(thunks: Array<() => Promise<any>>): Promise<any[]> — run tasks c