Changelog

You can now create a sandbox from the Vercel Node 26 runtime, providing the latest node.js features in the current major version

You can now automate time-based traffic movement for Vercel Flags using progressive rollouts. Unlike weighted splits which maintain stable traffic distribution for experiments, progressive rollouts automatically advance through a predefined...

The Vercel Sandbox firewall now supports forwarding specific requests to a proxy. This can be useful to log, debug, or transform HTTP requests or responses initiated from a sandbox.

Chat SDK now supports Messenger, extending its single-codebase approach to Slack, Discord, GitHub, Teams, and Telegram with the new Messenger adapter.

Chat SDK now supports browser chat UIs. Bring your bot to a React app via useChat, with the same handlers that fire on Slack, Discord, and Teams.

Persist per-user message history that follows the same person across every Chat SDK adapter, with the new transcripts and identity options.

Next.js 15.5.18 and 16.2.6 patch 13 security advisories covering middleware bypass, denial of service, SSRF, cache poisoning, and cross-site scripting.

Vercel Flags now supports JSON types alongside boolean, string, and number values. Store structured configuration data directly in feature flags without additional database lookups.