Definition
The payload is the object you write for an event: `supabase.from('events').insert({ name: 'checkout_completed', plan_tier: 'pro', amount: 99 })`. Each key maps to a column on the event table, queryable in filters and breakdowns.
Why payloads break quietly
Most SDKs accept arbitrary keys, so renaming `plan` to `plan_tier` does not raise an error. The new event keeps flowing under the new name. Any dashboard filter or breakdown that referenced `plan` silently returns nothing.