//最近一个公司项目需要对接firebase推送，官方文档就是谢特,再网上找了很多大神的资料，还是有很多坑，把自己踩的坑记录一下,平时都是伸手党，这次回馈一下

use Google\Client;

/**
 * 注意需要准备vpn
 * 1.安装sdk composer require google/apiclient:^2.12.1
 * 2.firebase推送，如要本地调试需找到vendor/guzzlehttp/guzzle/src/Handler/CurlFactory.php 中 applyHandlerOptions 方法，设置$options['verify'] = false;
 * @param $param ['title'=>推送标题，'body'=>推送信息]
 * @param $token 设备token
 * @return bool|string
 */
public function send($param, $token)
{
    $client = new Client();
    $client->useApplicationDefaultCredentials();
    $client->setAuthConfig($this->app->getRootPath() . 'public/path/to/xxxx-xxxx-3f599409d1e3.json');//引入json秘钥
    $client->setScopes('https://www.googleapis.com/auth/firebase.messaging');     # 授予访问 FCM 的权限
    // 你的 Firebase 项目 ID
    $project      = "firebase-aca99";
    $send_url     = "https://fcm.googleapis.com/v1/projects/{$project}/messages:send";
    $access_token = $client->fetchAccessTokenWithAssertion();//获取秘钥
    if (!isset($access_token['access_token'])) {
        Log::error('推送失败，未获取到秘钥');
        return false;
    }
    $accessToken = $access_token['access_token'];//秘钥
    //推送参数
    $params = [
        "message" => [
            "token"        => $token, //需要发送的设备号
            "notification" => $param
        ]
    ];
    //header请求头，$accessToken 就是你上面获取的令牌
    $header = [
        'Content-Type: application/json',
        'Authorization: Bearer ' . $accessToken,
    ];
    $response = http_post($send_url, json_encode($params), ['headers' => $header]);
    $response = json_decode($response,true);
    if(isset($response['name'])){
        return true;
    }elseif(isset($response['error'])){
        Log::error("推送失败:{$response['error']['code']},{$response['error']['message']}");
        return false;
    }

出处：https://www.cnblogs.com/aiyinsitan/p/16968237.html