Here is some general knowledge about integrate payment with Zalopay by my self-learning.

Documents: https://beta-docs.zalopay.vn/docs/openapi

1. General Flow

You only need to focus some keys and 2 API:

• Key: app_id, mac_key, callback_key information from Zalopay

• Create Order API

• Query Order API

You only need to understand main concepts:

• Step 1: User -> Merchant BE -> Create Order -> Zalopay => Zalopay return order_url (can used to create QR).

• Step 2: User -> order_url -> Payment success => Fallback (Redirect) to Merchant BE -> Update merchant inventory in merchant BE -> Show success in merchant FE.

• Step 3: In case of fallback failed by network, can use Query API to check the transaction status.

2. Business Model

2.1. Payment Gateway

2.2. Multifunction QR (VietQR)

This QR is generated from order_url, can be paid by: flexibly use any banking application (Vietcombank, OCB,…) or digital wallet.

2.3. Apple Pay

2.4. Google Pay

2.5. Quick Pay (Personal QR)

2.6. POS QR Code

2.6.1. Static QR

• Only need to print QR of merchant account => User scan by hand and input the amount, manually check.

2.6.2. Dynamic QR

• Case 1: Merchant input amount in POS, example 100k VND => POS generate static QR.

• Case 2: QR is generated in merchant website, for example: Tiki based on total amount => Dynamic QR by price.

2.7. Tokeninzation Payments

Used in monthly billing products or subscription.

2.7.1. Wallet Token

• Auto payment for monthly bill by amount in wallet.

2.7.2. Card Token

• Auto payment for monthly bill by credit card.

2.7.3. Subcription

• Use to pay for subscription in credit cards.

2.8. Cash on delivery (directly payment)

• This is pay when receive shipping of food, mobility, ordered products of shipper.

3. API Details

Docs: https://beta-docs.zalopay.vn/docs/openapi

3.1. Order

1. Create order: /v2/create

Here is some main fields

• app_id: The app that merchant register with zalopay.

• app_trans_id: merchant generate for tracking.

• amount: amount of order.

• redirect_url: fallback url of merchant for Zalopay to notify the process the transaction (success/failed)

• mac: It is signature of order. It’s calculated by following input: hmac_input = app_id

  app_trans_id

  app_user

  amount

  app_time

  embed_data

  item with SHA256.

1. Query: /v2/query

Here is some main fields

• app_id

• app_trans_id

• mac

3.2. Refund

1. Refund transaction: /v2/refund

Here is some main fields

• app_id

• m_refund_id: refund id.

• zp_trans_id: transaction id.

• amount: the amount to refund.

• mac

1. Query refund: /v2/query_refund

Here is some main fields

• app_id

• m_refund_id

• mac

3.3. Binding

1. Bind token: /v2/tokenization/bind

2. Query token: /v2/tokenization/query

3. Bind aggrement: /v2/agreement/bind

4. Unbind aggrement: /v2/agreement/unbind

5. Request for agreement pay (merchant call): /v2/agreement/pay

6. Query user balance: /v2/agreement/balance

3.4. OAuth

Notes:

• Generate authorization token only required client_id + privileges.

• Generate access_token required authorization token + client_id + client_secret.

• Generate authorization first to prevent man of the middle attack.

• The tranfer token flow should only be by 2 servers.