Make any TypeScript Function Durable

use workflow brings durability, reliability, and observability to async JavaScript. Build apps and AI Agents that can suspend, resume, and maintain state with ease.

Get Started

npm i workflow

Reliability-as-code

Move from hand-rolled queues and custom retries to durable, resumable code with simple directives.

export async function welcome(userId: string) {
  "use workflow";
  const user = await getUser(userId);
  const { subject, body } = await generateEmail({
    name: user.name, plan: user.plan
  });
  const { status } = await sendEmail({
    to: user.email,
    subject,
    body,
  });
  return { status, subject, body };
}

Queueing the getUser step...

Effortless setup

With a simple declarative API to define and use your workflows.

Creating a workflow

import { sleep } from "workflow";
import {
  createUser,
  sendWelcomeEmail,
  sendOneWeekCheckInEmail
} from "./steps"

export async function userSignup(email) {
  "use workflow";

  // Create the user and send the welcome email
  const user = await createUser(email);
  await sendWelcomeEmail(email);

  // Pause for 7 days
  // without consuming any resources
  await sleep("7 days");
  await sendOneWeekCheckInEmail(email);

  return { userId: user.id, status: "done" };
}

Defining steps

import { Resend } from 'resend';
import { FatalError } from 'workflow'; 

export async function sendWelcomeEmail(email) {
  "use step"

  const resend = new Resend('YOUR_API_KEY');

  const resp = await resend.emails.send({
    from: 'Acme <onboarding@resend.dev>',
    to: [email],
    subject: 'Welcome!',
    html: `Thanks for joining Acme.`,
  });

  if (resp.error) {
    throw new FatalError(resp.error.message);
  }
};

// Other steps...

Deep integration with AI SDK. Use familiar AI SDK patterns, plus durability, observability, and retries so agents stay reliable in production.

Durable agents by default. High-performance streaming, persistence, and resumable runs work out of the box. No infrastructure setup required.

Inspect every run end‑to‑end.

When deploying workflow on Vercel, deep workflow observability is built into the Vercel dashboard with no configuration or storage.

Status

Running

Run IDwrun_02456KXR

Duration0ms

workflow()

925ms

fetchOrder()

230ms

validate()

155ms

enrichWithPricing()

230ms

saveOrder()

155ms

sendEmail()

155ms

Zero infrastructure management. Fluid compute, serverless functions, queues and persistence work out of the box.

Deploy confidently. Running workflows continue on their original version while new executions use the latest code.

VGxkwTd46Preview

Building

30s

GFsdgf33wProduction

Ready

56s

REsdf2dsxPreview

Ready

49s

LDDgfrT21Production

Ready

59s

No timeout limits. Write long-running workflows without worrying about execution limits.

workflowTrigger()

10s

230ms

waiting

155ms

Pay for what you use. Only pay for actual execution time, not idle resources.

10s

idle

10s

idle

10s

Run anywhere, no lock‑in

The same code runs locally on your laptop, in Docker, on Vercel or any other cloud. Open source and portable by design.

export async function welcome(userId: string) {
  "use workflow";
  
  const user = await getUser(userId);
  const { subject, body } = await generateEmail({
    name: user.name, plan: user.plan
  });
  
  const { status } = await sendEmail({
    to: user.email,
    subject,
    body,
  });
  
  return { status, subject, body };
}

Build anything with

Build reliable, long-running processes with automatic retries, state persistence, and observability built in.

export async function aiAgentWorkflow(query: string) {
  "use workflow";

  // Step 1: Generate initial response
  const response = await generateResponse(query);

  // Step 2: Research and validate
  const facts = await researchFacts(response);

  // Step 3: Refine with fact-checking
  const refined = await refineWithFacts(response, facts);

  return { response: refined, sources: facts };
}

Get started quickly

See Workflow SDK in action with one of our templates.

Story Generator Slack Bot

Slackbot that generates children's stories from collaborative input.

Flight Booking App

Use Workflow to make AI agents more reliable and production-ready.

Natural Language Image Search

A free, open-source template for building natural language image search.

What builders say about Workflow SDK

Michael Carter@michaelcaaarter

We just migrated to use workflowand it's beautiful. Production app here, VC backed and many real fortune 100 customers using our app daily… not sure why you wouldn't use workflow to move fast and focus on building a great experience.

Nick Tikhonov@nick_tikhonov

fully migrated to workflows - our use case are AI agents that execute over a multiple-day time frame, making multiple outbound voice calls and processing the resultsbefore:
- scheduling service
- queues
- workers
- cron jobsnow: - 5 functions in one file🤯

Ryan Carson@ryancarson

What a time to be a content marketer.Sheesh this is mind-blowing.Built a complete end-to-end workflow with @ampcode using @WorkflowDevKit and @vercel AI Gateway- Custom DurableAgent tools for research
- Opus 4.5 for generation
- Gemini 3 Pro for content verification
- Nano Banana for image creationAEO locked in.

Ale Vigano@ale__vigano

During my time at @mercadopago we struggled a lot with concurrency issues handling millions of payments.Hard to believe that almost all the complexity I remember from back then is now solved with just a use workflow

Create your first workflow today.

Get started