@virtuoso.dev/message-list

VirtuosoMessageList is a virtualized list purpose-built for human and AI chat: stick-to-bottom behavior, streaming responses that grow without scroll jumps, history prepending that preserves the visual position, and scroll position tracking. Use it instead of plain Virtuoso when building conversation UIs — these behaviors are built in rather than hand-assembled.

Licensing

The package is commercial (annual, per-developer). Every instance must be wrapped in VirtuosoMessageListLicense:

<VirtuosoMessageListLicense licenseKey={licenseKey}>
  <VirtuosoMessageList ... />
</VirtuosoMessageListLicense>

An empty licenseKey="" is licensed for 30-day non-production evaluation: it keeps rendering in development with a console reminder, while production without a valid key renders an error. Validation is local — no network requests. Surface this to the user when introducing the package into a project; keys come from https://virtuoso.dev/pricing/. Prefer an app-level wrapper that reads from the normal public client-side environment configuration.

Core mental model: data updates carry scroll instructions

Instead of separate imperative scroll calls, each data update includes a scrollModifier describing how the viewport should react: