invoiceninja/app/controllers/QuoteApiController.php

<?php

use ninja\repositories\InvoiceRepository;
use Invoice;

class QuoteApiController extends Controller {

  protected $invoiceRepo;

  public function __construct(InvoiceRepository $invoiceRepo)
  {
    $this->invoiceRepo = $invoiceRepo;
  } 

  public function index()
  {    
    if (!Utils::isPro()) {
      Redirect::to('/');
    }

    $invoices = Invoice::scope()->where('invoices.is_quote', '=', true)->orderBy('created_at', 'desc')->get();
    $invoices = Utils::remapPublicIds($invoices->toArray());

    $response = json_encode($invoices, JSON_PRETTY_PRINT);
    $headers = Utils::getApiHeaders(count($invoices));
    return Response::make($response, 200, $headers);
  }

  /*  
  public function store()
  {
    $data = Input::all();
    $invoice = $this->invoiceRepo->save(false, $data, false);

    $response = json_encode($invoice, JSON_PRETTY_PRINT);
    $headers = Utils::getApiHeaders();
    return Response::make($response, 200, $headers);
  }
  */
}