> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/useautumn/autumn/llms.txt
> Use this file to discover all available pages before exploring further.

# Check Balance

Checks whether a customer currently has enough balance to use a feature. Optionally combines checking and consuming balance in a single atomic operation.

## Authentication

Requires a valid API secret key in the `Authorization` header:

```
Authorization: Bearer YOUR_SECRET_KEY
```

## Request Body

<ParamField body="customer_id" type="string" required>
  The ID of the customer.
</ParamField>

<ParamField body="feature_id" type="string" required>
  The ID of the feature to check access for.
</ParamField>

<ParamField body="entity_id" type="string">
  The ID of the entity for entity-scoped balances (e.g., per-seat limits).
</ParamField>

<ParamField body="required_balance" type="number" default={1}>
  Minimum balance required for access. Returns `allowed: false` if the customer's balance is below this value.
</ParamField>

<ParamField body="send_event" type="boolean">
  If true, atomically records a usage event while checking access. The `required_balance` value is used as the usage amount. This combines check + track in one call.
</ParamField>

<ParamField body="properties" type="object">
  Additional properties to attach to the usage event if `send_event` is true. Accepts any key-value pairs.
</ParamField>

<ParamField body="with_preview" type="boolean">
  If true, includes upgrade/upsell information in the response when access is denied. Useful for displaying paywalls.
</ParamField>

## Query Parameters

<ParamField query="skip_cache" type="boolean">
  If true, bypasses the cache and fetches fresh data.
</ParamField>

<ParamField query="expand" type="string">
  Comma-separated list of fields to expand. Available options:

  * `balance.feature`: Include full feature object in the balance response
</ParamField>

## Response

<ResponseField name="allowed" type="boolean">
  Whether the customer is allowed to use the feature. True if they have sufficient balance or the feature is unlimited/boolean.
</ResponseField>

<ResponseField name="customer_id" type="string">
  The ID of the customer that was checked.
</ResponseField>

<ResponseField name="entity_id" type="string">
  The ID of the entity, if an entity-scoped check was performed.
</ResponseField>

<ResponseField name="required_balance" type="number">
  The required balance that was checked against.
</ResponseField>

<ResponseField name="balance" type="object">
  The customer's balance for this feature. Null if the customer has no balance for this feature.

  <ResponseField name="feature_id" type="string">
    The feature ID this balance is for.
  </ResponseField>

  <ResponseField name="granted" type="number">
    Total balance granted (included + prepaid).
  </ResponseField>

  <ResponseField name="remaining" type="number">
    Remaining balance available for use.
  </ResponseField>

  <ResponseField name="usage" type="number">
    Total usage consumed in the current period.
  </ResponseField>

  <ResponseField name="unlimited" type="boolean">
    Whether this feature has unlimited usage.
  </ResponseField>

  <ResponseField name="overage_allowed" type="boolean">
    Whether usage beyond the granted balance is allowed (with overage charges).
  </ResponseField>

  <ResponseField name="max_purchase" type="number">
    Maximum quantity that can be purchased as a top-up, or null for unlimited.
  </ResponseField>

  <ResponseField name="next_reset_at" type="number">
    Timestamp when the balance will reset, or null for no reset.
  </ResponseField>

  <ResponseField name="breakdown" type="array">
    Detailed breakdown of balance sources when stacking multiple plans or grants.

    <ResponseField name="id" type="string">
      The unique identifier for this balance breakdown.
    </ResponseField>

    <ResponseField name="plan_id" type="string">
      The plan ID this balance originates from, or null for standalone balances.
    </ResponseField>

    <ResponseField name="included_grant" type="number">
      Amount granted from the plan's included usage.
    </ResponseField>

    <ResponseField name="prepaid_grant" type="number">
      Amount granted from prepaid purchases or top-ups.
    </ResponseField>

    <ResponseField name="remaining" type="number">
      Remaining balance available for use.
    </ResponseField>

    <ResponseField name="usage" type="number">
      Amount consumed in the current period.
    </ResponseField>

    <ResponseField name="unlimited" type="boolean">
      Whether this balance has unlimited usage.
    </ResponseField>

    <ResponseField name="reset" type="object">
      Reset configuration for this balance, or null if no reset.

      <ResponseField name="interval" type="string">
        Reset interval: `day`, `week`, `month`, or `year`.
      </ResponseField>

      <ResponseField name="resets_at" type="number">
        Timestamp when the next reset occurs.
      </ResponseField>
    </ResponseField>

    <ResponseField name="price" type="object">
      Pricing configuration if this balance has usage-based pricing.
    </ResponseField>

    <ResponseField name="expires_at" type="number">
      Timestamp when this balance expires, or null for no expiration.
    </ResponseField>
  </ResponseField>

  <ResponseField name="feature" type="object">
    The full feature object if `expand=balance.feature` was used.
  </ResponseField>
</ResponseField>

<ResponseField name="preview" type="object">
  Upgrade/upsell information when access is denied. Only present if `with_preview` was true and `allowed` is false.
</ResponseField>

## Example Request

### Simple Check

```bash theme={null}
curl -X POST https://api.autumnai.com/v1/balances.check \
  -H "Authorization: Bearer YOUR_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "customer_id": "cus_123",
    "feature_id": "messages"
  }'
```

### Check and Consume (Atomic)

```bash theme={null}
curl -X POST https://api.autumnai.com/v1/balances.check \
  -H "Authorization: Bearer YOUR_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "customer_id": "cus_123",
    "feature_id": "messages",
    "required_balance": 3,
    "send_event": true
  }'
```

## Example Response

```json theme={null}
{
  "allowed": true,
  "customer_id": "cus_123",
  "entity_id": null,
  "required_balance": 1,
  "balance": {
    "feature_id": "messages",
    "granted": 100,
    "remaining": 72,
    "usage": 28,
    "unlimited": false,
    "overage_allowed": false,
    "max_purchase": null,
    "next_reset_at": 1773851121437,
    "breakdown": [
      {
        "id": "cus_ent_39qmLooixXLAqMywgXywjAz96rV",
        "plan_id": "pro_plan",
        "included_grant": 100,
        "prepaid_grant": 0,
        "remaining": 72,
        "usage": 28,
        "unlimited": false,
        "reset": {
          "interval": "month",
          "resets_at": 1773851121437
        },
        "price": null,
        "expires_at": null
      }
    ]
  }
}
```

## Error Responses

<ResponseField name="error" type="object">
  <ResponseField name="message" type="string">
    Human-readable error message.
  </ResponseField>

  <ResponseField name="code" type="string">
    Machine-readable error code. Common codes:

    * `customer_not_found`: The specified customer doesn't exist
    * `feature_not_found`: The specified feature doesn't exist
    * `invalid_inputs`: Request validation failed
    * `entity_not_found`: The specified entity doesn't exist
    * `insufficient_balance`: Customer doesn't have enough balance (when `send_event` is true)
  </ResponseField>
</ResponseField>

### Example Error Response

```json theme={null}
{
  "error": {
    "message": "Customer has insufficient balance",
    "code": "insufficient_balance"
  }
}
```