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# sendFax

> Send a fax document on a call.

[faxaction]: /docs/server-sdks/reference/typescript/relay/actions

[calling-call-fax]: /docs/server-sdks/reference/typescript/relay/call#events

[call-events]: /docs/server-sdks/reference/typescript/relay/call#events

Send a fax document on the call. The document must be accessible via URL.
Returns a [`FaxAction`][faxaction] that you can
use to stop the fax or wait for it to complete.

> **Info**
>
> This method emits [`calling.call.fax`][calling-call-fax] events. See [Call Events][call-events] for payload details.

## **Parameters**

**`document`** `string` — required

URL of the document to fax (PDF or TIFF format).

---

**`identity`** `string | undefined`

Caller identity string (TSI) transmitted with the fax.

---

**`headerInfo`** `string | undefined`

Header text printed at the top of each fax page.

---

**`controlId`** `string | undefined`

Custom control ID. Auto-generated if not provided.

---

**`onCompleted`** `(event: RelayEvent) => void | Promise<void>`

Callback invoked when the fax operation completes.

---

## **Returns**

`Promise<`[`FaxAction`][faxaction]`>` -- An action handle with
`stop()` and `wait()` methods.

## **Example**

```typescript {12}
import { RelayClient } from '@signalwire/sdk';

const client = new RelayClient({
  project: process.env.SIGNALWIRE_PROJECT_ID!,
  token: process.env.SIGNALWIRE_API_TOKEN!,
  contexts: ['default']
});

client.onCall(async (call) => {
  await call.answer();

  const action = await call.sendFax(
    'https://example.com/invoice.pdf',
    { identity: '+15559876543', headerInfo: 'Invoice #12345' }
  );
  const event = await action.wait();

  const faxResult = event.params.fax as Record<string, unknown> ?? {};
  console.log(`Fax sent: ${faxResult.pages ?? 0} pages`);
  await call.hangup();
});

await client.run();
```

> Send a fax document on a call.