Pranay Prakash
196f91f669
The set that stops a replay pass from re-publishing step messages this invocation already sent was keyed by correlation id alone. The dispatch path treats (correlationId, stepName) as the step's identity (stepDispatchIdempotencyKey) because a corrected replay can rebind a correlation id to a different step; keyed by id alone, a later pass would skip that step's only dispatch. The suspension handler now reports the steps it published as dispatch keys (queuedStepDispatchKeys) and the runtime seeds, checks and adds the same composite key. A runtime test taps the engine's output to rebind the queued step's correlation id on the second pass and asserts it is dispatched under its new identity. Addresses https://github.com/vercel/workflow/pull/4128#discussion_r3993283137 Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Workflow SDK
Workflow SDK makes TypeScript and JavaScript functions durable. It persists workflow progress, retries failed steps, and provides built-in observability. Workflows can suspend without using compute while they wait.
Quick start
Install the SDK in an existing project:
npm install workflow
Configure the integration for your framework. For example, with Next.js:
// next.config.ts
import { withWorkflow } from 'workflow/next';
export default withWorkflow({});
Then start a workflow from an API route, Server Action, or other server-side code:
import { start } from 'workflow/api';
import { onboardUser } from './workflows/onboard-user';
await start(onboardUser, ['hello@example.com']);
Run your app, then open the local observability UI in another terminal:
npm run dev
npx workflow web
Choose your framework in the getting-started guides.
Note
The
workflowpackage includes its full documentation, so coding agents can read version-matched guides locally fromnode_modules/workflow/docs.
Run anywhere
Local development uses the bundled backend with no configuration. Deploy to Vercel for managed storage, queuing, scaling, and observability. To self-host, use the Postgres backend or implement a custom World.
The Worlds page lists maintainer-curated third-party Worlds, including self-hosted and managed options. Submit your World by updating the Worlds Manifest.
Community
The Workflow SDK community lives on GitHub Discussions, where you can ask questions, share ideas, and show what you have built.
Contributing
Contributions are welcome. Use issues and discussions to collaborate with the team and wider community. By participating, you agree to our Code of Conduct.
Security
If you find a security vulnerability in Workflow SDK, disclose it responsibly instead of opening a public issue.
To participate in our Open Source Software Bug Bounty program, please email responsible.disclosure@vercel.com. We will add you to the program and provide further instructions for submitting your report.