# Customer
**Kind:** interface
**Defined in:** `packages/zappier/src/auth.ts`
## Fields
| Field | Type | Meaning |
|-------|------|---------|
| `id` | `string` | cust_… |
| `name` | `string` | Display |
| `tierId` | `string` | Matches TierConfig.id |
| `apiKey` | `string` | x-api-key value |
| `multiplierOverride` | `number?` | Beats tier multiplier |
| `email` | `string?` | Portal login |
## Who constructs it
CustomerRepo.findByApiKey / findById
## Who consumes it
`apiKeyAuth`, `portal`, `invoices`, `usage.summaryFor`
## Related modules
See `docs/modules/` for the functions that take these types as parameters and the values they return.