effect-workflow

effect-workflow is a skill for Claude Code, Codex from mpsuesser/pi-effect-harness. It costs 45 tokens per session (5,958 once invoked), scanned A, original, MIT.

A guide for building Effect workflows that continue through restarts and coordinate delayed or distributed work. Effect is a TypeScript library for structuring programs with explicit effects and resources.

In plain words
What is it for?
Use it to define durable workflows with activities, timers, signals, persisted queues, compensation steps, and Effect Cluster distribution.
Why use it?
It helps handle retries, saved progress, delays, waiting for signals, background queues, and rollback steps in long-running processes.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/mpsuesser/pi-effect-harness/effect-workflow
Any agent
npx skills add mpsuesser/pi-effect-harness --skill effect-workflow
Clone the repo
git clone --depth 1 https://github.com/mpsuesser/pi-effect-harness

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for effect-workflow

README.md
[![agentmods](https://agentmods.dev/badge/skills/mpsuesser/pi-effect-harness/effect-workflow.svg)](https://agentmods.dev/skills/mpsuesser/pi-effect-harness/effect-workflow)
Your own site
<a href="https://agentmods.dev/skills/mpsuesser/pi-effect-harness/effect-workflow"><img src="https://agentmods.dev/badge/skills/mpsuesser/pi-effect-harness/effect-workflow.svg" alt="Measured on agentmods" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,958 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00045 $0.05958
Opus 5 $0.00023 $0.02979
Sonnet 5 $0.00009 $0.01192
Haiku 4.5 $0.00005 $0.00596

Measured 5d ago against content hash 55c3f7efcf85, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

effect-workflow scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

harnesses/effect/skills/effect-workflow/SKILL.md · 803 lines

How it starts

The opening of the file, as written. The whole thing — 803 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an Effect TypeScript expert specializing in durable workflow execution using the effect/unstable/workflow module.

Effect Source Reference

The Effect v4 source is available at ~/.cache/effect-v4/. Browse and read files there directly to look up APIs, types, and implementations.

Key source files:

  • packages/effect/src/unstable/workflow/Workflow.ts — Workflow definition, compensation, annotations
  • packages/effect/src/unstable/workflow/Activity.ts — Activity definition, retry, idempotency
  • packages/effect/src/unstable/workflow/WorkflowEngine.ts — Engine service, in-memory layer, encoded interface
  • packages/effect/src/unstable/workflow/DurableClock.ts — Durable sleep/timers
  • packages/effect/src/unstable/workflow/DurableDeferred.ts — Durable signal/wait, tokens, done/succeed/fail
  • packages/effect/src/unstable/workflow/DurableQueue.ts — Durable queue handing work to persisted background workers

IMPORTANT: Unstable API

The workflow module lives under effect/unstable/workflow. APIs may change between versions. All imports use this path:

import {
	Workflow,
	Activity,
	WorkflowEngine,
	DurableClock,
	DurableDeferred,
	DurableQueue
} from 'effect/unstable/workflow';

Core Concepts

Effect Workflow provides durable execution — workflows that survive process restarts through event sourcing. The key idea: activities are the units of side-effectful work whose results get persisted. On replay, persisted results are returned without re-executing the activity.

Architecture

Workflow  →  defines the overall process (name, payload, success/error schemas)
Activity  →  a discrete unit of work inside a workflow (results are persisted)
WorkflowEngine  →  orchestrates execution, replay, suspension, resumption
DurableClock  →  sleep/timer that persists across restarts
DurableDeferred  →  wait-for-external-signal that persists across restarts
DurableQueue  →  hand work to a persisted background worker and await its result

Read the full file on GitHub · 803 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 803 lines · 45 tokens per session scan A 55c3f7efcf85

Subscribe to this mod's changes

effect-workflow is a skill published in the GitHub repository mpsuesser/pi-effect-harness (24 stars, last pushed 2mo ago), licensed MIT. It adds 45 tokens to every session and 5,958 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.