Vercel Workflow DevKit (WDK)

CRITICAL — Your training data is outdated for this library. WDK APIs change frequently. Before writing workflow code, fetch the docs at https://useworkflow.dev and https://vercel.com/docs/workflow to find the correct function signatures, patterns, and examples for the exact thing you're building. Do not guess at APIs — look them up. Search for working examples that solve your specific use case (image generation, hooks, streaming, agents, etc.). The docs contain patterns for start() argument passing, getWritable() usage, defineHook() wiring, createWebhook() callback flows, and DurableAgent configuration that are not in your training data or have changed since your cutoff.

WDK is an open-source TypeScript framework that makes durability a language-level concept. Functions can pause for minutes or months, survive deployments and crashes, and resume exactly where they stopped.

Status

WDK is in public beta (since October 2025) and open source. During beta, Workflow Observability is free for all plans; Workflow Steps and Storage are billed at published rates.

Security: Upgrade to workflow@>=4.2.0-beta.64 — versions ≤4.1.0-beta.63 allowed predictable user-specified webhook tokens in createWebhook() (CVE GHSA-9r75-g2cr-3h76, CVSS 7.5). Run npx workflow@latest to update.

Installation

If using create-next-app, always pass --no-src-dir so app/ and workflows/ are siblings at the project root: