- decompress() now gates only on DecompressionStream (read path), not
CompressionStream — reads work in decompress-only runtimes (Copilot).
- Cross-deployment writes (start({deploymentId}), resumeHook) restrict to
the portable gzip codec via a new compressionPortableOnly flag. zstd
decode needs node:zlib >= 22.15, a property of the reader's runtime that
the SDK (engines: Node 18+) can't guarantee for a different deployment;
same-deployment writes still use zstd since reader == writer (vercel bot).
- Browser zstd WASM is now vendored into web-shared dist and referenced via
a relative new URL('./zstd.wasm', import.meta.url) — a bare package
specifier was left unrewritten by Vite and 404'd. Verified the Vite build
emits the asset (karthikscale3).
- hydrateResourceIOWithKey accepts an optional key and always registers the
zstd decoder, so unencrypted compressed payloads (e.g. local world) are
inflated; web no-key hydration paths now route through it (karthikscale3).
- Clarify the sync-decompress doc contract (best-effort via
process.getBuiltinModule, not "always on Node") (Copilot).
Tests: cross-deployment gzip fallback, unencrypted compressed web
hydration, and zstd WASM ↔ node:zlib compatibility.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Getting Started
The Workflow SDK lets you easily add durability, reliability, and observability to async JavaScript. Build apps and AI agents that can suspend, resume, and maintain state with ease.
Visit https://workflow-sdk.dev to view the full documentation.
Community
The Workflow SDK community can be found on GitHub Discussions, where you can ask questions, voice ideas, and share your projects with other people.
Contributing
Contributions to Workflow SDK are welcome and highly appreciated. Please use GitHub issues and discussions to collaborate with the team and wider community.
Author list
Workflow SDK was built by engineers at Vercel and the Open Source Community.
The initial core contributing engineers are:
- Adrian Lam (@adriandlam)
- Dillon Mulroy (@dmmulroy)
- Gal Schlezinger (@Schniz)
- JJ Kasper (@ijjk)
- Nathan Rajlich (@TooTallNate)
- Peter Wielander (@VaguelySerious)
- Pranay Prakash (@pranaygp)
The Workflow SDK logo was designed by Cecilio Ruiz @ceciliorz
Security
If you believe you have found a security vulnerability in Workflow SDK, we encourage you to responsibly disclose this and not open 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.