# Authentication and limits

Get an API key in the [Integrations](https://dash.bitsby.app/integrations/list) section.

## Capabilities

* **Invoice management:** creation, cancellation, status checks
* **Payment management:** listing payments, matching a payment to an invoice
* **Statistics:** aggregated data by project, period, wallet, and more
* **Billing:** project fee rates, balances

## Limits

* **Request rate:** at most 1 request per second per key
* **Number of keys:** 10 per account

## Request authorization

Pass your API key in the `Authorization` header to authorize every API request.

An example of the `Authorization` header in an API request:

```bash
curl -X POST https://api.bitsby.app/invoices/list \
  -H "Authorization: Token MSvL2ltaDZdWVjmZURURMVWhqSJLT2NURjhL2Fla1Z1T1IxQTltKs1T3Ay"
```

## Server response

The API server always responds in JSON. Use the `result` parameter to tell whether the request succeeded.

An example response for a successful request:

```json
{
    "result": "success",
    "data": .....
}
```

An example response for an error:

```json
{
    "result": "error",
    "data": "Requests too frequent"
}
```