仔细阅读了微信接口文档并且参考网上的案例，完成了商家转账到零钱的接口开发，目前已在使用中
下面是完整代码：
public static function transfer($withdrawApply,$userAuth,$config) { //请求URL $url = 'https://api.mch.weixin.qq.com/v3/transfer/batches'; //请求方式 $http_method = 'POST'; //请求参数 $data = [ 'appid' => $config['app_id'],//申请商户号的appid或商户号绑定的appid（企业号corpid即为此appid） 'out_batch_no' => $withdrawApply['batch_no'],//商户系统内部的商家批次单号，要求此参数只能由数字、大小写字母组成，在商户系统内部唯一 'batch_name' => '提现至微信零钱',//该笔批量转账的名称 'batch_remark' => '提现至微信零钱',//转账说明，UTF8编码，最多允许32个字符 'total_amount' => $withdrawApply['left_money'] * 100,//转账金额单位为“分”。转账总金额必须与批次内所有明细转账金额之和保持一致，否则无法发起转账操作 'total_num' => 1,//一个转账批次单最多发起三千笔转账。转账总笔数必须与批次内所有明细之和保持一致，否则无法发起转账操作 'transfer_detail_list' => [ [//发起批量转账的明细列表，最多三千笔 'out_detail_no' => $withdrawApply['sn'],//商户系统内部区分转账批次单下不同转账明细单的唯一标识，要求此参数只能由数字、大小写字母组成 'transfer_amount' => $withdrawApply['left_money'] * 100,//转账金额单位为分 'transfer_remark' => '提现至微信零钱',//单条转账备注（微信用户会收到该备注），UTF8编码，最多允许32个字符 'openid' => $userAuth['openid'],//openid是微信用户在公众号appid下的唯一用户标识（appid不同，则获取到的openid就不同），可用于永久标记一个用户 ]] ]; if ($withdrawApply['left_money'] >= 2000) { if (empty($withdrawApply['real_name'])) { throw new \Exception('转账金额 >= 2000元，收款用户真实姓名必填'); } $data['transfer_detail_list'][0]['user_name'] = self::getEncrypt($withdrawApply['real_name'],$config); } $token = self::token($url,$http_method,$data,$config);//获取token $result = self::https_request($url,json_encode($data),$token);//发送请求 $result_arr = json_decode($result,true); if(!isset($result_arr['create_time'])) {//批次受理失败 throw new \Exception($result_arr['message']); } //批次受理成功，进行操作 return true; } public static function token($url,$http_method,$data,$config) { $timestamp = time();//请求时间戳 $url_parts = parse_url($url);//获取请求的绝对URL $nonce = $timestamp.rand('10000','99999');//请求随机串 $body = empty($data) ? '' : json_encode((object)$data);//请求报文主体 $stream_opts = [ "ssl" => [ "verify_peer"=>false, "verify_peer_name"=>false, ] ]; $apiclient_cert_arr = openssl_x509_parse(file_get_contents($config['cert_path'],false, stream_context_create($stream_opts))); $serial_no = $apiclient_cert_arr['serialNumberHex'];//证书序列号 $mch_private_key = file_get_contents($config['key_path'],false, stream_context_create($stream_opts));//密钥 $merchant_id = $config['mch_id'];//商户id $canonical_url = ($url_parts['path'] . (!empty($url_parts['query']) ? "?${url_parts['query']}" : "")); $message = $http_method."\n". $canonical_url."\n". $timestamp."\n". $nonce."\n". $body."\n"; openssl_sign($message, $raw_sign, $mch_private_key, 'sha256WithRSAEncryption'); $sign = base64_encode($raw_sign);//签名 $schema = 'WECHATPAY2-SHA256-RSA2048'; $token = sprintf('mchid="%s",nonce_str="%s",timestamp="%d",serial_no="%s",signature="%s"', $merchant_id, $nonce, $timestamp, $serial_no, $sign);//微信返回token return $schema.' '.$token; } public static function https_request($url,$data,$token) { $curl = curl_init(); curl_setopt($curl, CURLOPT_URL, (string)$url); curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE); curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE); if (!empty($data)){ curl_setopt($curl, CURLOPT_POST, 1); curl_setopt($curl, CURLOPT_POSTFIELDS, $data); } curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1); //添加请求头 $headers = [ 'Authorization:'.$token, 'Accept: application/json', 'Content-Type: application/json; charset=utf-8', 'User-Agent:Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36', ]; if(!empty($headers)){ curl_setopt($curl, CURLOPT_HTTPHEADER, $headers); } $output = curl_exec($curl); curl_close($curl); return $output; } public static function getEncrypt($str,$config) { //$str是待加密字符串 $public_key = file_get_contents($config['cert_path']); $encrypted = ''; if (openssl_public_encrypt($str, $encrypted, $public_key, OPENSSL_PKCS1_OAEP_PADDING)) { //base64编码 $sign = base64_encode($encrypted); } else { throw new \Exception('encrypt failed'); } return $sign; } public static function detailsQuery($withdrawApply,$config) { //请求URL $url = 'https://api.mch.weixin.qq.com/v3/transfer/batches/out-batch-no/'.$withdrawApply['batch_no'].'/details/out-detail-no/'.$withdrawApply['sn']; //请求方式 $http_method = 'GET'; //请求参数 $data = []; $token = self::token($url,$http_method,$data,$config);//获取token $result = self::https_request($url,$data,$token);//发送请求 $result_arr = json_decode($result,true); return $result_arr; }注意事项：
明细转账金额 >= 2,000元，收款用户姓名必填；
同一批次转账明细中，收款用户姓名字段需全部填写、或全部不填写；
转账受理成功后，需要调用《商家明细单号查询》接口来判断转账状态；
最后补上微信开发文档：商家转账到零钱-文档中心-微信支付商户平台
经过评论区老哥的提醒，参数里带有收款用户姓名，得在HTTP头部增加Wechatpay-Serial，Wechatpay-Serial后面带上平台证书序列号。
附上证书相关接口文档：证书相关 - WechatPay-API-v3
来源地址：https://blog.csdn.net/weixin_48337755/article/details/127449073
