Pranay Prakash
efbdc213a0
* [core] Make `hook.metadata` a lazy Promise getter Hydrating a hook's metadata is a decrypting READ: it needs the owning run's payload keys, and resolving those costs a run fetch plus a `run-key` API round trip (~350ms). `getHookByToken()` did that work eagerly on every lookup that found a metadata-bearing hook, so callers that only wanted `runId`/`token` — and hook resumption, which never reads metadata at all — paid for it anyway. `metadata` is now a getter returning a memoized Promise, the same shape as `run.returnValue`. The lookup is one read again; hydration and the key resolution behind it happen on first access, or never. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Co-Authored-By: Pranay Prakash <1797812+pranaygp@users.noreply.github.com> * docs: surface the lazy hook.metadata change in What's new, the migration skill, and the resumeHook reference Adds the breaking-change row to the v5 What's new page and puts that page in the sidebar as the first visible entry (the /v5/docs redirect to getting-started is unchanged). Teaches the migrating-workflow-v4-to-v5 skill the `await hook.metadata` rewrite and bumps its version. Points the resumeHook reference at HookWithLazyMetadata, and notes on the World storage page that world.hooks.getByToken() returns raw serialized metadata. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * [core] Export the lazy-metadata hook type as `Hook` from `workflow/api` `getHookByToken()` and `resumeHook()` return `Hook`, not a separate `HookWithLazyMetadata`: one public hook type whose `metadata` is a lazy Promise, mirroring `Run` for runs. The World-level record from `@workflow/world` is unchanged and is referenced as `WorldHook` inside the runtime. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * [core] Define the lazy `metadata` getter in place; tighten changeset and docs wording Review feedback: the hook record a World returns is a fresh object per lookup and the eager path mutated it anyway, so define the getter on it directly instead of copying it with Object.create(). The changeset is one sentence, and the docs describe hydration as extra network round trips rather than decryption, since not every World encrypts. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> --------- Co-authored-by: vercel[bot] <35613825+vercel[bot]@users.noreply.github.com> Co-authored-by: Pranay Prakash <1797812+pranaygp@users.noreply.github.com> 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.