> ## Documentation Index
> Fetch the complete documentation index at: https://docs.unprice.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Check access

> Resolve whether a feature is usable for a customer.

<RequestExample>
  ```ts theme={null}
  const { result, error } = await unprice.access.check({
    customerId: "cus_1234567890",
    featureSlug: "ai-messages"
  });

  if (error) {
    console.error(error.message);
    return;
  }

  console.log(result);
  ```
</RequestExample>

<ResponseExample>
  ```json theme={null}
  {
    "allowed": true,
    "featureSlug": "ai-messages",
    "usage": 42,
    "limit": 100,
    "spending": {
      "ledgerAmount": 4200000000,
      "currency": "USD",
      "displayAmount": "$42",
      "scale": 8
    }
  }
  ```
</ResponseExample>

## Request

<ParamField body="customerId" type="string" required>
  The customer ID to check.
</ParamField>

<ParamField body="featureSlug" type="string" required>
  The feature slug to check.
</ParamField>

<ParamField body="timestamp" type="number">
  Optional epoch-millisecond timestamp for a recent point-in-time check.
</ParamField>

## Response

<ResponseField name="allowed" type="boolean" required>
  Whether the feature is usable for the customer at the requested timestamp.
</ResponseField>

<ResponseField name="featureSlug" type="string" required>
  The feature slug that was checked.
</ResponseField>

<ResponseField name="rejectionReason" type="string">
  Why the feature is not usable. Omitted when `allowed` is `true`.
</ResponseField>

<ResponseField name="usage" type="number">
  Current usage for usage-based features.
</ResponseField>

<ResponseField name="limit" type="number">
  Configured limit for usage-based features, or `null` when unlimited.
</ResponseField>

<ResponseField name="spending" type="object">
  Current priced usage spend for usage-based features.
</ResponseField>

<ResponseField name="spending.ledgerAmount" type="number">
  Current spend in ledger scale units.
</ResponseField>

<ResponseField name="spending.currency" type="string">
  ISO currency code for the spend.
</ResponseField>

<ResponseField name="spending.displayAmount" type="string">
  Ready-to-render localized spend, such as `$42`.
</ResponseField>

<ResponseField name="spending.scale" type="number">
  Decimal scale for `ledgerAmount`. Currently `8`.
</ResponseField>