Payment Apps
The payment-app domain manages two kinds of credentials: mobile apps (login and checkout credentials of each client's mini programs) and open-platform app registration (WeChat Official Accounts / mini programs, Douyin apps, etc. — required when JSAPI and mini-program payments fetch the openId). Menu: Payment Management → Payment Apps.
What gets registered here are "the apps the platform / merchants applied for on open platforms such as WeChat and Douyin"; channel-side receiving credentials are configured on the channel merchant — the two work together.
Mobile App Config
Entry: Payment Management → Payment Apps → Mobile Apps. First pick the client (merchant mini program / admin mini program / cashier mini program), then configure each mini program's credentials on per-platform tabs:
| Platform | What to fill in |
|---|---|
| WeChat mini program | Mini-program AppId, AppSecret, original ID (starting with gh_, optional) |
| Alipay mini program | AppId, auth mode (public-key mode: app private key + Alipay public key; certificate mode: app private key + the three certificate files) |
| Douyin mini program | AppId, AppSecret |
- These credentials serve login (mini-program clients logging into this system) and checkout (the cashier mini program launching payments).
- On save, only sensitive fields that changed are submitted; unchanged secrets are not re-submitted; a second confirmation is required before editing.
- The Android / iOS app tabs are reserved and not yet available.
The cashier mini program is special
The whole platform shares one set of cashier mini-program credentials. At payment time the openId and the receiving app must come from the same source: the platform mini program's AppId must be bound or registered on the payment channel in use (in ISV mode this is usually the ISV mini program + sub-merchant registration; for aggregate channels it is generally at the sub-app level) — not all channels work out of the box; confirm with the channel before integrating.
WeChat Apps (Hub)
Entry: Payment Management → Payment Apps → Payment Apps (WeChat). The page has two tabs, "Platform Apps / Merchant Apps":
| Tab | Purpose |
|---|---|
| Platform apps | Official Accounts, mini programs and mobile apps registered under the platform / ISV identity, referenced by product-level default bindings of the WeChat-family channels |
| Merchant apps | Official Accounts / mini programs owned by a specific merchant, used by that merchant's channel-merchant capability binding (pick the merchant first, then manage) |
Registration fields: app name, app type (Official Account / mini program / mobile app), AppId (globally unique, checked on save), AppSecret.
The app type cannot be changed freely
Changing the app type on edit automatically clears capability bindings incompatible with the new type; reconfigure the capability bindings after the change.
Capability Binding
WeChat Pay fetches the openId by pay capability, and different capabilities have compatibility requirements on the app type (e.g. JSAPI only accepts Official Accounts, mini-program payment only accepts mini programs, QR and barcode accept several types). Binding happens at two levels:
| Level | Entry | Effect |
|---|---|---|
| Product-level default | "Platform default capabilities" of each WeChat-family ISV product | The fallback used by channel merchants under that product without an individual binding |
| Channel-merchant level | Channel merchant detail → App Management → Capability Binding | Specifies which app each capability uses for a single channel merchant |
In ISV (special merchant) mode, each capability can also choose "ISV default" — no individual binding, following the ISV-side config. Binding options only list apps compatible with the capability's type, preventing combinations that cannot be used.
Douyin Apps
The structure is identical to the WeChat hub (platform apps / merchant apps / capability binding), with differences:
- App types are mini program / mobile app / web app — no Official Accounts;
- Pay capabilities are the Douyin family (JSAPI, QR, H5, APP), with compatibility rules varying by capability.
WeChat Domain Verification
When configuring business domains / JS-interface security domains on the WeChat side, WeChat requires a verification file placed in the website root. The system hosts these files:
| Entry | Supported files | Scenario |
|---|---|---|
| Payment Management → Payment Apps → Domain Verification (platform level) | Verification files downloaded from WeChat (.txt / .html) | Verification hosting for platform domains, searchable by merchant number |
| Merchant Workbench → Business Config → WeChat Domain Verification (merchant level) | Only MP_verify_*.txt | Verification files for merchants' own domains (e.g. the merchant-side callback domain) |
When uploading, directly pick the original file downloaded from the WeChat Official Accounts platform; the system reads its content and hosts it under the payment domain. After uploading, complete the domain config on the WeChat platform at the address the system shows. Editing can only change the remark — to replace the file itself, delete it and upload again.
Related Links
- Channel Configuration (Common Operations) — the full flow of ISV keys, onboarding and capability binding
- Channel Merchants — the channel-side receiving identity
- Mobile Apps — how each client's mini programs relate to the system