| **Alipay (Direct)** | Desktop QR code, mobile Alipay redirect | Direct integration with Alipay Open Platform, returning desktop QR codes and mobile WAP/app launch links |
| **WeChat Pay (Direct)** | Native QR, H5, MP/JSAPI Pay | Direct integration with WeChat Pay APIv3 with environment-aware routing |
| **Stripe** | Card, Alipay, WeChat Pay, Link, etc. | International payments, multi-currency support |
> Alipay/WeChat Pay direct and EasyPay can both exist as backend provider instances, but the frontend always exposes only two visible buttons: `Alipay` and `WeChat Pay`. Admins choose exactly one source for each visible method: direct or EasyPay. Direct channels connect to payment APIs directly with lower fees; EasyPay aggregates through third-party platforms with easier setup.
> **EasyPay Provider Recommendations**: Both options below are third-party aggregators compatible with the EasyPay protocol. Pick based on the funding channel and settlement currency you need:
>
> - **Domestic channel / CNY settlement** — [ZPay](https://z-pay.cn/?uid=23808) (`https://z-pay.cn/?uid=23808`): direct integration with official Alipay / WeChat Pay APIs, fee **1.6%**; funds go straight to the merchant account with **T+1 automatic settlement**. Supports **individual users** (no business license required) with up to 10,000 CNY daily transactions; business-licensed accounts have no limit. Link contains the referral code of [Sub2ApiPay](https://github.com/touwaeriol/sub2apipay) original author [@touwaeriol](https://github.com/touwaeriol) — feel free to remove it.
> - **International channel / USDT or USD settlement** — [Kyren Topup](https://kyren.top/?code=SUB2API) (`https://kyren.top/?code=SUB2API`): a ready-to-launch global payment stack for AI startups with WeChat Pay and Alipay support, local-currency checkout, and USD settlement. Fees: WeChat 2%, Alipay 2.5%; withdrawal 0.1% (min $40, max $150), settled in **USDT or USD**. No qualification review required — sign up and use immediately, making it the lowest barrier to entry. Withdrawal threshold is relatively high, recommended for users **who do not use domestic Chinese payment channels, cannot tolerate Stripe's 6%+ fees, have high transaction volume, and have USD or USDT channels to receive withdrawn funds**. Kyren Topup charges a $200 account opening fee; signing up via this link (which contains Sub2Api author [@Wei-Shaw](https://github.com/Wei-Shaw)'s referral code) **waives the opening fee**. Feel free to remove it if you prefer.
>
> Please evaluate the security, reliability, and compliance of any third-party payment provider on your own — this project does not endorse or guarantee any of them.
---
## Quick Start
1. Go to Admin Dashboard → **Settings** → **Payment Settings** tab
| **Order Timeout** | Order timeout in minutes (minimum 1) | 30 |
| **Max Pending Orders** | Maximum concurrent pending orders per user | 3 |
| **Load Balance Strategy** | Strategy for selecting provider instances | Round Robin |
### Frontend Visible Method Routing
The current payment UX keeps the frontend method list unified and does not expose provider brands directly:
- **Alipay**: when enabled, this button must be routed to either `Alipay (Direct)` or `EasyPay Alipay`
- **WeChat Pay**: when enabled, this button must be routed to either `WeChat Pay (Direct)` or `EasyPay WeChat`
- Each visible method can route to only one source at a time
- If a visible method is enabled without a selected source, the frontend will not expose that method
### Load Balance Strategies
| Strategy | Description |
|----------|-------------|
| **Round Robin** | Distribute orders to instances in rotation |
| **Least Amount** | Prefer instances with the lowest daily cumulative amount |
### Cancel Rate Limiting
Prevents users from repeatedly creating and canceling orders:
| Setting | Description |
|---------|-------------|
| **Enable Limit** | Toggle |
| **Window Mode** | Sliding / Fixed window |
| **Time Window** | Window duration |
| **Window Unit** | Minutes / Hours |
| **Max Cancels** | Maximum cancellations allowed within the window |
### Help Information
| Setting | Description |
|---------|-------------|
| **Help Image** | Customer service QR code or help image (supports upload) |
| **Help Text** | Instructions displayed on the payment page |
---
## Provider Configuration
Each provider type requires different credentials. Select the type when adding a new provider instance in **Provider Management → Add Provider**.
> **Callback URLs are auto-generated**: When adding a provider, the Notify URL and Return URL are automatically constructed from your site domain. You only need to confirm the domain is correct.
### EasyPay
Compatible with any payment service that implements the EasyPay protocol.
| Parameter | Description | Required |
|-----------|-------------|----------|
| **Merchant ID (PID)** | EasyPay merchant ID | Yes |
Direct integration with Alipay Open Platform. Mobile flows return an Alipay WAP/app redirect URL. Desktop flows prefer Face-to-Face Precreate QR payloads; if the merchant has not enabled that product, the provider falls back to Computer Website Pay and also returns the cashier URL so the frontend can render a QR code or open the hosted checkout page directly.
> Replace `your-domain.com` with your actual domain. For EasyPay / Alipay / WeChat Pay, the callback URL is auto-filled when adding the provider — no manual configuration needed.
### Stripe Webhook Setup
1. Log in to [Stripe Dashboard](https://dashboard.stripe.com/)
2. Go to **Developers → Webhooks**
3. Add an endpoint with the callback URL
4. Subscribe to events: `payment_intent.succeeded`, `payment_intent.payment_failed`
5. Copy the generated Webhook Secret (`whsec_...`) to your provider configuration
### Important Notes
- Callback URLs must use **HTTPS** (required by Stripe, strongly recommended for others)
- Ensure your firewall allows callback requests from payment platforms
- The system automatically verifies callback signatures to prevent forgery
- Balance top-up is processed automatically upon successful payment — no manual intervention needed
---
## Payment Flow
```
User selects amount and payment method
│
▼
Create Order (PENDING)
├─ Validate amount range, pending order count, daily limit
| `FAILED` | Balance credit failed, admin can retry |
| `REFUND_REQUESTED` | Refund requested |
| `REFUNDING` | Refund in progress |
| `REFUNDED` | Refund completed |
### Timeout and Fallback
- Before marking an order as expired, the background job queries the upstream payment status first
- If the user has actually paid but the callback was delayed, the system will reconcile automatically
- The background job runs every 60 seconds to check for timed-out orders
---
## Migrating from Sub2ApiPay
If you previously used [Sub2ApiPay](https://github.com/touwaeriol/sub2apipay) as an external payment system, you can migrate to the built-in payment system:
### Key Differences
| Aspect | Sub2ApiPay | Built-in Payment |
|--------|-----------|-----------------|
| Deployment | Separate service (Next.js + PostgreSQL) | Built into Sub2API, no extra deployment |
| Configuration | Environment variables + separate admin UI | Unified in Sub2API admin dashboard |
| Top-up Integration | Via Admin API callback | Internal processing, more reliable |
| Subscription Plans | Supported | Not yet (planned) |
| Order Management | Separate admin interface | Integrated in Sub2API admin dashboard |
### Migration Steps
1. Enable payment in Sub2API admin dashboard and configure providers (use the same payment credentials)
2. Update webhook callback URLs to Sub2API's callback endpoints
3. Verify that new orders are processed correctly via built-in payment
4. Decommission the Sub2ApiPay service
> **Note**: Historical order data from Sub2ApiPay will not be automatically migrated. Keep Sub2ApiPay running for a while to access historical records.
