Workflow

Reusable, ESM-only, edge-ready durable execution

@visulima/workflow lets you write a long-running process as a plain async function and makes it resumable: it survives process restarts, hour-long delays and waits for external events, replaying deterministically from an append-only history. It is the generic engine that powers higher-level features such as @visulima/notification's workflow steps, but it has no notification dependency and is useful on its own.

Why @visulima/workflow?

• Infra-free - No dashboard, no SaaS account, no separate server process. Bring any store you already run.
• Edge-ready - The engine core and the in-memory / unstorage stores are fetch + Web Crypto only, with zero Node built-ins, so they run unmodified on Cloudflare Workers, Vercel Edge, Deno and Bun.
• Code-first - Workflows are ordinary async functions; durability comes from ctx.step / ctx.sleep / ctx.waitForEvent, not a YAML DSL or a visual editor.
• Type-safe - Payloads are validated and typed via any Standard Schema validator (Zod, Valibot, ArkType).
• Pluggable durability - A small WorkflowStore contract; an in-memory and an unstorage store ship in the box, and you can back runs with Redis, Postgres or a Durable Object.

How it works

You define a workflow and drive it through a runtime:

import { createRuntime, defineWorkflow } from "@visulima/workflow";
import { z } from "zod";

const onSignup = defineWorkflow({
    id: "welcome",
    payload: z.object({ userId: z.string(), email: z.string() }),
    run: async (ctx) => {
        await ctx.step("send-welcome", () => sendEmail(ctx.payload.email, "Welcome!"));
        await ctx.sleep("wait-a-day", { amount: 1, unit: "days" });

        const activated = await ctx.step("check-activation", () => isActivated(ctx.payload.userId));

        if (!activated) {
            await ctx.step("send-nudge", () => sendEmail(ctx.payload.email, "Need a hand?"));
        }
    },
});

const runtime = createRuntime({ workflows: [onSignup] });

const { runId, status } = await runtime.trigger(onSignup, { userId: "u_1", email: "a@b.com" });
// status === "suspended" — the run is sleeping for a day.

The engine re-runs the workflow body from the top on every activation; already-completed steps short-circuit to their recorded result, and the first unsatisfied sleep/waitForEvent suspends the run. See Durability & replay for the model.

Next steps

• Installation
• Getting started
• Steps: the ctx contract
• Durability & replay
• Stores
• Concurrency & exactly-once