# `Stripe.Params.Billing.MeterCreateParams.DefaultAggregation`
[🔗](https://github.com/jeffhuen/tiger_stripe/blob/main/lib/stripe/params/billing/meter_create_params.ex#L48)

Nested parameters.

# `t`

```elixir
@type t() :: %Stripe.Params.Billing.MeterCreateParams.DefaultAggregation{
  formula: String.t() | nil
}
```

* `formula` - Specifies how events are aggregated. Allowed values are `count` to count the number of events, `sum` to sum each event's value and `last` to take the last event's value in the window. Possible values: `count`, `last`, `sum`.

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*Consult [api-reference.md](api-reference.md) for complete listing*