# PriceRule
**Kind:** discriminated union
**Defined in:** `packages/zappier/src/pricing.ts`
## Fields
| Field | Type | Meaning |
|-------|------|---------|
| `kind` | `'free' | 'fixed' | 'variable'` | Which list-price formula |
| `fixedCents` | `number?` | When kind=fixed, cents per call |
| `baseCents` | `number?` | When kind=variable, base cents |
| `perKbCents` | `number?` | When kind=variable, per KB metadata |
| `perMbCents` | `number?` | When kind=variable, per MB attachments |
## Who constructs it
RateCard.endpoints values
## Who consumes it
`quoteCall`, `meter`, `admin rate card UI`, `portal API & pricing tab`
## Related modules
See `docs/modules/` for the functions that take these types as parameters and the values they return.