Contract coverage
Know where the agent can build safely and where it is still guessing.
Design systems
Your design system should be a boundary, not a suggestion.
Userface turns component rules into a surface AI can compose against, validate, and preview before drift spreads.
AI will route around weak systems.
Generated UI is useful only when it respects the system you maintain. Otherwise it just creates faster entropy.
Token drift
Catch the moment output reaches around tokens and invents its own taste.
Uncontracted surfaces
Find the props and states production relies on but contracts forgot to name.
Primitive leaks
Stop one-off DOM from sneaking in as "just this once".
Governance
Make drift visible while it is still cheap.
Userface gives maintainers a watchlist for the surfaces that make generated UI brittle: missing states, loose props, primitive leaks, and token gaps.
+Components missing the states users actually hit.
+Props production uses but face.json cannot describe yet.
+Patterns too important to leave to blank-page generation.
+Token and API gaps that turn AI output into drift.
State matrix
BillingTable
default
loading
empty
overdue
payment_failedContract diff
Button
+ prop: loading
~ variant: default | accent | ghost | destructive
- deprecated: toneMake the design system hard to ignore.
Coverage, state gaps, token drift, primitive leaks. Bring the backlog that AI keeps exposing.