Event Delegation Budget

Use this when many repeated units attach pointer, hover, keyboard, drag, or selection handlers.

Rule

Delegate repeated handlers to a stable parent when possible. Use data-* identity for hit targets when it avoids per-unit closures.

Budget

• handler count per repeated unit
• total active handlers at target cohort
• hot handler allocations per render
• drag/resize event frequency
• pointer capture or passive listener policy

Treat 20+ handlers per repeated unit as a fire.

Use Vercel For

• client-event-listeners
• client-passive-event-listeners
• advanced-event-handler-refs

This rule owns per-unit handler budgets and data-attribute hit routing.