Base UI Basic Primitives

Scope

• Avatar, Button, Meter, Progress, Scroll Area, Separator

Routing cues

• "simple visual primitive", "separator", "avatar", "loading meter/progress", "scrollbar" → this skill

Canonical references

• https://base-ui.com/react/components/avatar
• https://base-ui.com/react/components/button
• https://base-ui.com/react/components/meter
• https://base-ui.com/react/components/progress
• https://base-ui.com/react/components/scroll-area
• https://base-ui.com/react/components/separator

Maintenance

• Snapshot date: 2026-02-13
• Refresh cadence: quarterly
• Upstream changelog anchor: https://github.com/mui/base-ui/blob/master/CHANGELOG.md

References

• Primitive API notes