Workflow SDK now writes over WebSockets on Vercel
The Vercel Workflow SDK has updated to send event writes and stream writes over WebSocket by default starting with version 5.2.0, eliminating the need for one HTTP request per write. This change improves performance, reduces costs, and enables faster AI token streaming—demonstrated by a 4.2× speed improvement in benchmarks. No code changes are required beyond upgrading to workflow@5.2.0 or later. Existing streaming code remains compatible, and in-flight workflows continue on their original deployment. Users should consult the upgrade guide if migrating from version 4.x.