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# RestError

> Error thrown when the REST API returns a non-success response.

Custom error class for REST API errors. Extends JavaScript's built-in `Error`
class. Thrown when an HTTP request to the SignalWire REST API returns a non-success
status code, or when the request never reaches the server. The `name` property is
`"RestError"`, or `"RestTransportError"` for the transport subclass below.

Also exported as `SignalWireRestError` to match the Python SDK class name.

```typescript {1}
import { RestError } from "@signalwire/sdk";
```

## **Properties**

**`statusCode`** `number | null`

HTTP status code returned by the API (e.g., `404`, `422`, `500`). `null` for
a `RestTransportError`, where no response was received.

---

**`body`** `string | SignalWireErrorBody`

Response body from the API. A `SignalWireErrorBody` object (`code`,
`message`, and optional `more_info` and `status`) when the response was valid
JSON; otherwise the raw text. For a `RestTransportError`, the underlying
transport error message.

---

**`url`** `string`

The URL that was requested.

---

**`method`** `string`

The HTTP method used (`"GET"`, `"POST"`, `"PUT"`, `"PATCH"`, `"DELETE"`).

---

**`headers`** `Record<string, string> | null`

Response headers from the failed request. `null` for a transport failure.

---

**`requestId`** `string | null`

The platform request ID read from the response headers, or `null` when
absent. Quote it when you contact support about a failed request.

---

**`name`** `string`

`"RestError"`, or `"RestTransportError"` for a transport failure.

---

**`message`** `string`

Human-readable summary: `"{method} {url} returned {statusCode}: {body}"` for
an HTTP error, or `"{method} {url} failed to reach the server: {body}"` for a
transport failure. Followed by `(request-id: ...)` when a request ID is
available.

---

## **RestTransportError**

Thrown when a request never reaches a response: a connection refused, a DNS
failure, a TLS error, or a `RequestOptions` timeout. It extends `RestError`, so
one `catch (e instanceof RestError)` handles HTTP errors and transport failures
alike. `statusCode`, `headers`, and `requestId` are `null`, and `body` holds the
underlying transport error message.

Also exported as `SignalWireRestTransportError`.

```typescript {1}
import { RestTransportError } from "@signalwire/sdk";
```

## **Example**

```typescript {9}
import { RestClient, RestError } from "@signalwire/sdk";

const client = new RestClient({
  project: "your-project-id",
  token: "your-api-token",
  host: "your-space.signalwire.com"
});

try {
  await client.phoneNumbers.get("nonexistent-id");
} catch (e) {
  if (e instanceof RestError) {
    console.log(`HTTP ${e.statusCode}: ${e.body}`);
    console.log(`Request: ${e.method} ${e.url}`);
    console.log(`Request ID: ${e.requestId}`);
  }
}
```

> Error thrown when the REST API returns a non-success response.