Open-core · early beta

Simulate & record chat interactions in the UIs people know.

Script a conversation once — typing, reactions, a reply being sent — and play it back inside a pixel-faithful Slack, iMessage, terminal, or your own captured UI. Drop a <Typecaast> on a page, or export an MP4. One JSON config, two render targets, identical frames.

Open the playground →View on GitHub

Cory Watilo: i got a billing toast error on the dashboard but i think it's a bug?
Paul D'Ambra: @PostHog the billing/spend API call shouldn't show an error toast to the user…
PostHog: Let me check how exceptions are captured in the frontend.
PostHog: Pull request opened — guards the billing/spend call so it no longer toasts on error.

Pixel-faithful presets, light & dark

SlackiMessageMessages (macOS)WhatsAppDiscordClaude Code (TUI)Cursor panel

Embed it live

A real React component with a real-time player. `theme="auto"` follows the page, fonts load so it looks right everywhere.

Export it to video

The same engine + skins render deterministically through Remotion to MP4/GIF/WebM — frame-for-frame identical to the live preview.

Build any UI

Hand-authored presets, a public skin contract, a scaffold, and an AI skill — anyone can add a platform.