@anishthite/pi-better-workflows

Deterministic multi-agent workflows for Pi. This package registers a workflow tool that runs JavaScript orchestration scripts with subagents, background execution, resumable journals, phases, structured output, and optional git worktree isolation.

It is intentionally close to Claude Code's Workflow tool semantics, with one Pi-specific safety improvement: if a workflow result is truncated inline, the tool description tells the assistant to read the persisted run journal before answering.

Install

pi install npm:@anishthite/pi-better-workflows

For local development:

pi install /absolute/path/to/pi-better-workflows

The package manifest exposes ./extensions/workflow.ts through the pi.extensions field, so Pi loads it as a normal package extension.

Both this package and other workflow extensions may register a tool named workflow. Enable only one at a time.

Quick start

Ask Pi to run a workflow, or call the tool directly with a script:

export const meta = {
  name: 'summarize-files',
  description: 'Summarize important project files',
  phases: [
    { title: 'Read', detail: 'Inspect files' },
    { title: 'Synthesize', detail: 'Merge findings' },
  ],
}

phase('Read')
const summaries = await pipeline(
  ['README.md', 'package.json'],
  file => agent(`Read ${file} and summarize the useful facts.`, {
    label: `read:${file}`,
    phase: 'Read',
  })
)

phase('Synthesize')
return await agent(`Combine these summaries:\n${summaries.join('\n\n')}`, {
  label: 'final',
  phase: 'Synthesize',
})

The tool returns a runId immediately. Results are delivered back into the conversation when the background run finishes.

Tool API

workflow accepts:

Field	Purpose
script	Inline workflow JavaScript. Must start with export const meta = { ... }.
scriptPath	Run a previously saved workflow script.
name	Run a named/saved workflow when available.
args	JSON value exposed to the script as global args.
resumeFromRunId	Replay unchanged completed agent() calls from a prior run journal.
title, description	Accepted for compatibility and ignored; use meta instead.

Script runtime

Workflow scripts are plain JavaScript running in a deterministic sandbox.

Globals:

Global	Purpose
agent(prompt, opts)	Spawn a Pi subagent; returns text or schema-validated JSON.
pipeline(items, ...stages)	Run items through async stages without a barrier between stages.
parallel(thunks)	Run async thunks concurrently and wait for all of them.
phase(title)	Move subsequent work into a progress phase.
log(message)	Emit workflow progress.
workflow(ref, args)	Run one nested workflow.
args	User-provided JSON input.
budget	{ total, spent(), remaining() }; total is currently null.

Useful agent() options:

Option	Purpose
label	Short unique label for progress and resume identity.
phase	Explicit phase assignment.
schema	JSON Schema for structured output.
model	Per-agent model override.
effort	Per-agent reasoning effort override.
isolation: 'worktree'	Run the agent in a temporary git worktree.
agentType	Use a named Pi subagent definition.

Determinism rules: Date.now(), Math.random(), and argless new Date() throw inside the sandbox so resume stays stable.

Caps: concurrent agents are limited to min(16, cpu cores - 2), each run can create up to 1000 agents, and one pipeline()/parallel() call can process up to 4096 items.

Commands and storage

Use /workflows in Pi to inspect recent workflow runs.

Runtime files are stored under:

~/.pi/better-workflows/scripts/  # persisted inline scripts
~/.pi/better-workflows/runs/     # run journals and results

If an inline completion is truncated, read the full journal before summarizing:

jq '.result' ~/.pi/better-workflows/runs/<runId>.json

Development

# Pure runtime smoke tests
node $(npm root -g)/pi-subagents/node_modules/jiti/lib/jiti-cli.mjs test/smoke.ts

# Pi SDK load check
node --import $(npm root -g)/pi-subagents/node_modules/jiti/lib/jiti-register.mjs test/loadcheck.ts

Package contents

extensions/workflow.ts   Pi extension entry point
src/tool.ts              tool schema and registration
src/runtime.ts           workflow sandbox and runtime globals
src/agent.ts             Pi subagent bridge
src/manager.ts           background run manager
src/persistence.ts       script and journal storage
src/worktree.ts          git worktree isolation
src/structured-output.ts structured_output helper for schema agents
test/                    smoke, load, probe, and e2e checks

License

MIT