开发者文档

身份认证

在仪表盘的「API 密钥」中创建密钥，并在每个请求中以 Bearer token 发送。测试密钥（sk_test_…）创建测试付款；正式密钥（sk_live_…）会转移真实资金。

Authorization: Bearer sk_live_...   # or sk_test_...
Base URL: https://api-business.kemapp.io

Complete business verification (KYB) before creating payments. In the current API this applies to both test and live keys, even though a test key can be created earlier. Owners, admins, developers and custom roles with API-key management permission can create keys; select the intended organization first.

Call this API from your server. Each key belongs to one business and one mode; no X-Org header is needed. Reads return only that key's mode. Keep secrets in your server's secret store, and revoke compromised keys in the dashboard. Dashboard sessions and their private endpoints use a separate authentication flow.

付款

创建付款并将客户引导至托管的 checkout_url——钱包、网络与确认全部由 Kem 处理。可通过查询付款跟踪状态，更推荐使用 Webhooks。

curl -X POST https://api-business.kemapp.io/v1/payments \
  -H "Authorization: Bearer sk_test_..." \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: order-1042" \
  -d '{
  "amount": "25.000000",
  "currency": "USDT",
  "merchant_reference": "order-1042",
  "customer_email": "[email protected]",
  "description": "Pro plan",
  "return_url": "https://yourshop.example/thanks",
  "metadata": {
    "order_id": "1042"
  }
}'

{
  "id": "pay_example",
  "status": "pending",
  "mode": "test",
  "amount": "25.000000",
  "amount_minor": 25000000,
  "amount_refunded_minor": 0,
  "fee_bps": null,
  "fee_minor": null,
  "net_minor": null,
  "currency": "USDT",
  "network": null,
  "merchant_reference": "order-1042",
  "customer_email": "[email protected]",
  "description": "Pro plan",
  "return_url": "https://yourshop.example/thanks",
  "metadata": {
    "order_id": "1042"
  },
  "checkout_url": "https://dashboard.business.kemapp.io/pay/pay_example",
  "checkout_expires_at": "2026-09-22T13:30:00+00:00",
  "transaction_id": null,
  "detected_at": null,
  "confirmation_pending": false,
  "created_at": "2026-09-22T13:00:00+00:00",
  "updated_at": "2026-09-22T13:00:00+00:00"
}

Returns HTTP 201. Example ids are placeholders. Save the returned id, mode and order reference, then use the returned checkout_url rather than constructing a checkout address.

amount

Required decimal string, e.g. 25 or 25.000000. Positive, at most six decimal places; no JSON number or scientific notation.

currency

USDT; defaults to USDT when omitted.

merchant_reference

Optional order/reference string. Store the returned payment id against your own order.

customer_email

Optional valid customer email.

description

Optional description displayed with the payment.

return_url

Optional destination after checkout. A browser redirect is not proof of successful payment.

metadata

Optional JSON object stored on the payment and returned by payment reads. It is not currently copied into webhook payloads.

Idempotency-Key — 可选但推荐——在默认的 24 小时窗口内，相同 key 和请求体会重放原始响应。

The default retention window is 24 hours and keys are scoped to the business. Within that window, the same key and body replay the original response; a changed body returns 409. After expiry, reuse can create another payment. Keep test and live idempotency keys distinct, and use a fresh key for each new order or simulation scenario.

curl "https://api-business.kemapp.io/v1/payments?limit=20&status=succeeded" \
  -H "Authorization: Bearer sk_test_..."

List responses contain data, has_more and next_cursor. Pass next_cursor as cursor on the next request, retaining your filters. Both reads return HTTP 200. A payment belonging to another business or mode is returned as payment_not_found.

amount — decimal string with 6 places in responses ("25.000000"); amount_minor — the same value as an integer in micro-USDT.

fee_minor and net_minor are null while a payment is in flight and are frozen when it succeeds. Reconcile your payout against net_minor, not amount_minor — the difference is our fee (fee_bps).

付款生命周期

pending → detected → succeeded · failed · expired · refunded (legacy)

pending——等待付款 · detected——确认中 · succeeded——已完成（仅在 live 模式下履约）· failed / expired——终态。历史付款也可能具有 refunded 状态。

The default checkout window is 30 minutes. A pending payment with a submitted transaction hash gets a default 24-hour grace period after that window; confirmation_pending and payment.confirmation_delayed flag the delay. Detected payments wait for settlement or a terminal failure. Neither a hash, a redirect, nor a delayed-confirmation event proves payment. Use the payment's status and your stored mode before fulfilling an order.

错误与限制

所有错误使用同一信封。code 是稳定的——请依据 error.code 分支，而不是文案。

HTTP 4xx/5xx
{
  "error": {
    "code": "idempotency_conflict",
    "message": "Idempotency-Key reused with a different request"
  }
}

产品、可重复使用的支付链接和 Webhook 端点在仪表盘配置，而非通过公开 API 密钥端点管理。目前仪表盘和商户 API 均不提供商户主动发起退款的功能。

Webhooks

在仪表盘「Webhooks」中添加端点并选择事件。创建时会返回 whsec_… 签名密钥；获得授权的用户可在仪表盘中再次查看。

事件负载

{
  "id": "evt_example",
  "type": "payment.succeeded",
  "created": "2026-09-22T13:04:12+00:00",
  "data": {
    "payment": {
      "id": "pay_example",
      "status": "succeeded",
      "amount_minor": 25000000,
      "currency": "USDT",
      "merchant_reference": "order-1042",
      "network": null,
      "product_id": null,
      "payment_link_id": null,
      "fee_minor": 0,
      "net_minor": 25000000
    }
  }
}

This is a zero-fee success example. fee_minor and net_minor are nullable before success. Payment webhooks currently omit mode, customer_email and the original metadata. Keep your own payment-id-to-order/mode mapping; retrieve an unknown payment with the appropriate key before acting. A simulated payment.succeeded must not fulfill a live order.

验证签名

每次推送都带有 Kem-Signature。对「<t>.」加原始请求字节验证 HMAC，并做恒定时间比较；拒绝与当前时间相差超过 300 秒的时间戳，并按事件 id 去重。

Kem-Signature: t=<unix_timestamp>,v1=<hmac_sha256_hex>

signed_input = "<t>." + raw_request_body
v1 = HMAC_SHA256(endpoint_secret, signed_input)   # secret: whsec_...

# reject replays: drop the delivery when |now - t| > 300s
# also deduplicate the event body id before applying business effects

import crypto from "node:crypto";

export function verifyKemSignature(rawBody, header, secret) {
  if (!Buffer.isBuffer(rawBody) || typeof header !== "string") return false;
  const match = /^t=([0-9]{1,16}),v1=([0-9a-fA-F]{64})$/.exec(header.trim());
  if (!match) return false;

  const timestamp = Number(match[1]);
  if (!Number.isSafeInteger(timestamp)) return false;
  if (Math.abs(Date.now() / 1000 - timestamp) > 300) return false;

  const expected = crypto.createHmac("sha256", secret)
    .update(match[1] + ".")
    .update(rawBody) // exact bytes, before JSON parsing
    .digest();
  const received = Buffer.from(match[2], "hex");
  return crypto.timingSafeEqual(expected, received);
}

import hashlib
import hmac
import re
import time

def verify_kem_signature(raw_body: bytes, header: str, secret: str) -> bool:
    if not isinstance(header, str):
        return False
    match = re.fullmatch(r"t=([0-9]{1,16}),v1=([0-9a-fA-F]{64})", header.strip())
    if match is None:
        return False
    if abs(time.time() - int(match[1])) > 300:
        return False

    expected = hmac.new(
        secret.encode(), (match[1] + ".").encode() + raw_body, hashlib.sha256
    ).digest()
    return hmac.compare_digest(expected, bytes.fromhex(match[2]))

Verify before parsing JSON: use a Buffer from express.raw in Node, or raw request bytes such as request.get_data() in Flask. Do not reserialize a parsed object. These examples reject malformed headers, invalid signatures, and timestamps over five minutes in the past or future. Keep the receiver's clock synchronized.

投递与重试

请尽快返回 2xx。失败的投递会按退避策略重试，最终进入死信：

1m · 5m · 30m · 2h · 12h · 24h

There are seven attempts including the initial delivery. The delays above apply between retries. Deliveries may repeat or arrive out of order: deduplicate by the top-level event id, durably record or queue the event before acknowledging it, and keep fulfillment idempotent per payment. The timestamp/signature is refreshed on each retry. Review failed deliveries in Webhooks; use a payment read when you need its latest state.

测试

KYB 获批后，使用测试密钥创建付款并模拟 succeeded、failed 或 expired。这些调用可测试付款事件和 Webhooks，无需真实转账：

curl -X POST https://api-business.kemapp.io/v1/payments/{id}/_simulate/succeeded \
  -H "Authorization: Bearer sk_test_..."

Replace {id} with a test payment id. Supported event names are succeeded, failed and expired; live keys are rejected. Create a fresh payment for each terminal outcome. Use simulation for test payments rather than sending real funds. Test and live payments can notify the same subscribed webhook endpoint, so retain the mode from creation.