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

# Node.js SDK errors, retries, and timeouts

> Error classes, automatic retry behavior, and timeout configuration in the Telnyx Node.js SDK.

## Handling errors

When the library is unable to connect to the API,
or if the API returns a non-success status code (i.e., 4xx or 5xx response),
a subclass of `APIError` will be thrown:

```ts theme={null}
const numberOrder = await client.numberOrders
  .create({ phone_numbers: [{ phone_number: '+15558675309' }] })
  .catch(async (err) => {
    if (err instanceof Telnyx.APIError) {
      console.log(err.status); // 400
      console.log(err.name); // BadRequestError
      console.log(err.headers); // {server: 'nginx', ...}
    } else {
      throw err;
    }
  });
```

Error codes are as follows:

| Status Code | Error Type                 |
| ----------- | -------------------------- |
| 400         | `BadRequestError`          |
| 401         | `AuthenticationError`      |
| 403         | `PermissionDeniedError`    |
| 404         | `NotFoundError`            |
| 422         | `UnprocessableEntityError` |
| 429         | `RateLimitError`           |
| >=500       | `InternalServerError`      |
| N/A         | `APIConnectionError`       |

### Retries

Certain errors will be automatically retried 2 times by default, with a short exponential backoff.
Connection errors (for example, due to a network connectivity problem), 408 Request Timeout, 409 Conflict,
429 Rate Limit, and >=500 Internal errors will all be retried by default.

You can use the `maxRetries` option to configure or disable this:

```js theme={null}
// Configure the default for all requests:
const client = new Telnyx({
  maxRetries: 0, // default is 2
});

// Or, configure per-request:
await client.numberOrders.create({ phone_numbers: [{ phone_number: '+15558675309' }] }, {
  maxRetries: 5,
});
```

### Timeouts

Requests time out after 1 minute by default. You can configure this with a `timeout` option:

```ts theme={null}
// Configure the default for all requests:
const client = new Telnyx({
  timeout: 20 * 1000, // 20 seconds (default is 1 minute)
});

// Override per-request:
await client.numberOrders.create({ phone_numbers: [{ phone_number: '+15558675309' }] }, {
  timeout: 5 * 1000,
});
```

On timeout, an `APIConnectionTimeoutError` is thrown.

Note that requests which time out will be [retried twice by default](#retries).