1) 取本次请求的全部参数（不含 sign 自身）；
2) 按参数名 ASCII 升序排序，拼接成 k1=v1&k2=v2&…；
3) 末尾追加 &key=你的AppKey；
4) 对整串做 MD5 后转大写，即得 sign。

{
    "ok": 1,
    "msg": "请求成功",
    "data": [
        {
            "Name": "拇指云（厦门）软件有限公司",
            "CardNo": "91350205MA8TE0P97L",
            "Legal": "李建华",
            "RegNo": "350205201072016",
            "RegDay": "2021-06-17",
            "RegStatus": "存续"
        }
    ],
    "thispage": 1,
    "pagecount": 1,
    "count": 1
}

{
    "ok": 0,
    "msg": "请传入检索关键字【key】"
}

{
    "ok": 0,
    "msg": "余额不足，且无可用套餐，请充值后重试。"
}

{
    "ok": 0,
    "msg": "接口【企业列表高级检索】已停用，暂停调用，请联系管理员。"
}

缺少必要的参数【appid、sendtime、sign】请详看开发文档。
AppID不存在，请联系产品经理进行业务开通。
sendtime不是10位的数字。
时间戳超时，请重新请求。
签名校验失败。
余额不足，请充值后重试。
接口【XXX】已停用，暂停调用，请联系管理员。

curl -X POST "https://www.muzhiyun.com/api/company.so.do" \
  -H "Content-Type: application/json" \
  -d &#039;{"appid":"你的AppID", "sendtime":"<当前时间戳>", "sign":"<按签名算法计算>", "appid":"muzhiyun","sendtime":"1790784000","page":"1","key":"拇指云" }'

<?php
$appId  = "你的AppID";      // 没有则填 muzhiyun
$appKey = "你的AppKey";
$url    = "https://www.muzhiyun.com/api/company.so.do";

$params = [
    &#039;appid' => 'muzhiyun',
    &#039;sendtime' => '1790784000',
    &#039;page' => '1',
    &#039;key' => '拇指云',
];
// 以下三项由代码自动补，无需手填
$params["appid"]    = $appId;
$params["sendtime"] = (string)time();
ksort($params);
$src = &#039;';
foreach($params as $k=>$v) $src .= $k.&#039;='.$v.'&';
$src .= &#039;key='.$appKey;
$params["sign"] = strtoupper(md5($src));

$ch = curl_init();
curl_setopt_array($ch, [
    CURLOPT_URL            => $url,
    CURLOPT_POST           => true,
    CURLOPT_HTTPHEADER     => [&#039;Content-Type: application/json'],
    CURLOPT_POSTFIELDS     => json_encode($params, JSON_UNESCAPED_UNICODE),
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT        => 30,
]);

$resp = curl_exec($ch);
curl_close($ch);
echo $resp;

import time, hashlib, json, urllib.request

APP_ID  = "你的AppID"      # 没有则填 muzhiyun
APP_KEY = "你的AppKey"
URL     = "https://www.muzhiyun.com/api/company.so.do"

params = {
    "appid": "muzhiyun",
    "sendtime": "1790784000",
    "page": "1",
    "key": "拇指云",
}
params["appid"]    = APP_ID
params["sendtime"] = str(int(time.time()))
params = dict(sorted(params.items()))  # 参数名升序
sign_src = "&".join(f"{k}={v}" for k, v in params.items()) + "&key=" + APP_KEY
params["sign"] = hashlib.md5(sign_src.encode("utf-8")).hexdigest().upper()

req = urllib.request.Request(
    URL,
    data=json.dumps(params).encode("utf-8"),
    headers={"Content-Type": "application/json"},
    method="POST",
)
print(urllib.request.urlopen(req, timeout=30).read().decode("utf-8"))

const url = "https://www.muzhiyun.com/api/company.so.do";
const params = {
  'appid': 'muzhiyun',
  'sendtime': '1790784000',
  'page': '1',
  'key': '拇指云',
  appid: "你的AppID",
  sendtime: String(Math.floor(Date.now()/1000)),
  // sign: 按上文「签名算法」在前端算 md5(ksort(k=v&…)&key=AppKey) 后填入
};
fetch(url, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(params),
}).then(r => r.json()).then(console.log);