This gist accepts a search query and calls the IEX Cloud API to fetch all stock tickers that match the query.

autocomplete.php

<?php
require_once 'vendor/autoload.php';

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\JsonResponse;

$request = Request::createFromGlobals();

if (!isset($_ENV['IEX_TOKEN'])) {
    throw new Exception('IEX token not found.');
}

$token = $_ENV['IEX_TOKEN'];

$response = new JsonResponse();
$response->headers->set('Access-Control-Allow-Origin', '*');

if ($request->request->has('query')) {
    $query = $request->request->get('query');

    $search = json_decode(file_get_contents(
        "https://cloud.iexapis.com/stable/search/$query?token=$token"
    ));

    $results = [];
    foreach ($search as $item) {
        $results[] = $item->symbol;
    }

    $data = [
        'results' => $results,
    ];

    $response->setData($data);
} else {
    $response->setData('Search query not found');
    $response->setStatusCode(JsonResponse::HTTP_BAD_REQUEST);
}

$response->send();