EBP API Docs v0.5.12
EN

Payment Flow #

1. Payment Status Flowchart #

stateDiagram-v2
    state "Payment Request (1)" as 1
    state "Payment Complete (2)" as 2
    state "Payment Cancel (3)" as 3
    state "Payment Fail (4)" as 4
    state "Payment Pending (5)" as 5
    state "Pending Cancel (6)" as 6
    state "Partial Cancel (7)" as 7
    state "Payment Register (9)" as 9

    [*] --> 1
    1 --> 4
    1 --> 5
    1 --> 2 : Domestic credit cards complete immediately
    1 --> 9
    1 --> [*]

    5 --> 6
    5 --> 2 : Capture / Deposit in pending state
    5 --> [*]

    6 --> [*]

    2 --> 3 : Cancel entire payment
    2 --> 7 : Cancel part of payment
    2 --> [*]

    7 --> 7 : Continue partial cancellation until fully cancelled
    7 --> 3 : Becomes 'Payment Cancel' when fully cancelled
    7 --> [*]

    3 --> [*]
    4 --> [*]
    9 --> [*]

2. General Payment Flow #

Key Steps Description #

  1. Create Payment Intent: The store server acquires session and authentication information from the PG via EBP in advance.
  2. User Authentication: Perform authentication by redirecting to the EBP payment screen (2-1) or by directly implementing the PG SDK at the store (2-2).
  3. Payment Creation: The stage where the actual payment is created and authorized based on the authenticated data.
    • 3-1. API Method: The store server calls EBP's Payment Creation API after acquiring auth data from the browser to complete authorization. Finally, the Store redirects the user to the Success URL.
    • 3-2. Webhook Method: The user approves the payment directly on the PG screen (or SDK), and the PG finalizes the authorization. The user is then redirected to the Store's Success URL by the PG.
  4. Authorization Result (Webhook): Regardless of the finalization method, EBP processes the authorization result received from the PG and sends an Authorization Webhook to the store. The store receives this notification to finalize the order processing and present the payment completion to the user.
sequenceDiagram
    autonumber
    actor User as User
    participant Store as Store
    participant EBP as EBP
    participant PG as PG

    rect var(--mermaid-rect-gray)
        Note over User, PG: 1. Create Payment Intent
        User->>Store: Click checkout button
        Store->>EBP: Create Payment Intent (POST /api/v2/payment-intents)
        activate EBP
        EBP->>PG: Request payment session
        PG-->>EBP: Response session & keys (pgResponse)
        EBP-->>Store: Response paymentUrl & pgResponse
        deactivate EBP
    end

    rect var(--mermaid-rect-blue)
        Note over User, PG: 2. User Authentication
        alt 2-1. EBP Redirect Page (Wrapping)
            Store-->>User: Redirect to EBP payment page (paymentUrl)
            User->>EBP: Access EBP page & enter auth info
            EBP->>PG: Request payment authentication
        else 2-2. Merchant Direct SDK Implementation
            Store->>User: Render PG UI on Store page
            User->>PG: Enter auth info & request authentication via PG components
        end
    end
    
    rect var(--mermaid-rect-green)
        Note over User, PG: 3. Payment Creation
        alt 3-1. API Method (Store calls Payment Creation API)
            PG-->>User: Deliver authentication data
            User->>Store: Deliver auth data & request completion
            Store->>EBP: Request Payment Creation (POST /api/v2/payments)
            EBP->>PG: Final approval request
            PG-->>EBP: Response approval result
            EBP-->>EBP: Process authorized data
            EBP-->>Store: Response approval result
            Store-->>User: Redirect to Success URL
        else 3-2. Webhook Method (User creates payment directly via PG)
            PG->>PG: Approve payment
            PG-->>User: Redirect to Store Success URL
        end
    end

    rect var(--mermaid-rect-brown)
        Note over User, PG: 4. Authorization Result (Webhook)
        PG->>EBP: Authorization notice (Webhook)
        EBP->>EBP: Process authorized data
        EBP->>Store: Authorization notification (Webhook)
        Store-->>User: Display final payment complete page
    end

2.2. Payment Result Notification (Async) #

PGI Async Section: Retry 3 times on timeout, then call Notification Fail API (EBP_API_239).

Core Payment Completion Processing:

  1. Validate payment completion.
  2. Parse PG response data.
  3. Process EBP payment completion.
  4. Generate store response data.
  5. Send store purchase history.
sequenceDiagram
    autonumber 1
    participant Store2 as Store
    participant Core as Core (EBP)
    participant PGI as PGI (EBP)
    participant PG as PG

    PG->>PGI: Payment Complete Webhook
    activate PG
    activate PGI
    PGI->>Core: Payment Complete Notification
    activate Core
    Note over Core: Notification (EBP_API_238)
    
    Note right of Core: Payment Pending: PG('5')

    Core->>Store2: Create Purchase History (Async)
    activate Store2
    
    Store2-->>Core: Response
    deactivate Store2

    Core-->>PGI: Response
    deactivate Core
    
    PGI-->>PG: Webhook Response
    deactivate PGI
    deactivate PG

Pending state (before capture) may require partial cancellation processing.

2.3. Final Payment Completion via Capture #

sequenceDiagram
    autonumber 1
    participant Store2 as Store
    participant Core as Core (EBP)
    participant PGI as PGI (EBP)
    participant PG as PG (PG)

    Store2->>Core: Request Capture
    activate Store2
    activate Core
    Note over Core: Request (EBP_API_228)

    Core->>PGI: Request Capture
    activate PGI
    PGI->>PG: Request Capture
    activate PG
    PG-->>PGI: Response Capture Result
    deactivate PG
    PGI-->>Core: Response Capture Result
    deactivate PGI

    Note right of Core: Payment Complete: ('2')
    Core-->>Store2: Response Capture Result
    deactivate Core
    deactivate Store2

2.4. Purchase Confirmation #

Effect of Purchase Confirmation:

  1. Settlement proceeds for confirmed purchases.

    Conditions for Purchase Confirmation:
  2. User confirms purchase in order history.
  3. Automatically confirmed by batch job a certain period after delivery completion.
sequenceDiagram
    autonumber 1
    actor USER as User
    participant Store as Store
    participant Core as Core (EBP)

    USER->>Store: Confirm Purchase
    Store->>Core: Request Confirmation
    activate Store
    activate Core
    Note over Store, Core: Request (EBP_API_214)
    Core-->>Store: Response Purchase History Creation
    deactivate Core
    deactivate Store
    Store->>USER: Purchase Confirmation Alert

3. Token Payment Flow #

3.1. Token Registration Flow #

Token Registration: The user requests token registration from the Store, which calls the PG screen via Core.

sequenceDiagram
    actor USER as User
    participant Store as Store
    participant Core as EBP(Core)
    participant PGI as EBP(PGI)
    participant PG as PG (PG)
    autonumber
 
    rect var(--mermaid-rect-blue)
        Note over USER, Core: 1. Token Registration Initialization
        USER->>Store: Request Token Registration
        activate Store
        Store->>Core: Prepare Registration (EBP_API_120)
        activate Core
        Core-->>Store: Response Registration URL
        deactivate Core
        Store-->>USER: Redirect to Registration URL (HTTP 3xx)
        deactivate Store
    end
 
    rect var(--mermaid-rect-beige)
        Note over USER, PG: 2. User Authentication & Registration 
        USER->>PGI: Redirect to Registration URL (HPP)
        activate PGI
        Note over PGI: EBP HPP (Redirect)
        PGI->>PG: Call PG Registration Screen
        activate PG
        Note over USER, PG: 3. User Input & Registration Authorization
        PG-->>PGI: Transfer Result (Callback/Redirect)
        deactivate PG
     end
 
    rect var(--mermaid-rect-gray)
        Note over USER, Store: 4. Notification
        PGI-->>USER: Redirect to Store Return URL (HTTP 3xx)
        deactivate PGI
        USER->>Store: Return to Complete Page
        Note over PG, Store: Asynchronous Processing (Webhook)
        PG->Core: Token Registration Webhook
        Core->>Store: Token Registration Webhook
    end

    rect var(--mermaid-rect-pink)
        Note over USER, Core: 5. PIN Registration (Optional: If required by Store)
        USER->>Store: Register PIN 
        Store->>Core: Register Encrypted PIN (EBP_API_131)
    end

3.2. Token Payment #

3.2.1. Customer-Initiated Payment #

sequenceDiagram
    actor USER as User
    participant Store as Store
    participant Core as EBP(Core)
    participant PG as PG (PG)
    autonumber

    rect var(--mermaid-rect-green)
        Store ->> Core: Request Payment (EBP_API_230)
        activate Store
        Note over USER, Core: PIN Verification (Optional: If a PIN is registered)
        Store-->>USER: Request PIN Verification
        USER->>Store: Enter PIN 
        Store->>Core: Verify Encrypted PIN (EBP_API_126)
        Core-->>Store: PIN Verification Result
    end
    rect var(--mermaid-rect-pink)
        Store ->> Core: Request Payment (EBP_API_230)
        activate Core
        Note right of Core: State: Payment Request('1')
        Core ->> PG : Process Payment Request 
        PG -->> Core: Payment Complete Notification (Callback/Redirect)
        Core -->> Store: Create Purchase History & Deliver Data
        deactivate Core
        deactivate Store
        Store -->> USER: Display Order Complete Page
    end

3.2.2. Merchant‑Initiated Subscription Payment #

sequenceDiagram
    actor USER as User
    participant Store as Store
    participant Core as EBP(Core)
    participant PGI as EBP(PGI)
    participant PG as PG (PG)
    autonumber
 
    rect var(--mermaid-rect-blue)
        activate Store
        Store ->> Core: Request Payment (EBP_API_230)
        activate Core
        Note right of Core: State: Payment Request('1')
        Core ->> PG : Process Payment Request
        PG -->> Core: Payment Complete Notification (Callback/Redirect)
        Core -->> Store: Create Purchase History & Deliver Data
        deactivate Core
        deactivate Store
    end

3.3. Delete Registered Token #

Delete Token: Deletes a registered token upon user request.

sequenceDiagram
    autonumber 1
    actor USER as User
    participant Store as Store
    participant Core as Core (EBP)
    participant PGI as PGI (EBP)

    USER->>Store: Request Token Deletion
    activate Store
    Note over Store, Core: Delete Token (EBP_API_124)
    Store->>Core: Call Delete Token API
    activate Core
    Core->>PGI: Request Deletion
    activate PGI
    PGI-->>Core: Response
    deactivate PGI
    Core-->>Store: Response Result
    deactivate Core
    Store-->>USER: Token Deletion Completion Message
    deactivate Store

3.4. Query Registered Tokens #

Query Token: The user queries the list of previously registered tokens.

sequenceDiagram
    autonumber 1
    actor USER as User
    participant Store as Store
    participant Core as Core (EBP)

    USER->>Store: Request Token List
    activate Store
    Note over Store, Core: Query Token (EBP_API_109)
    Store->>Core: Call Query Token API
    activate Core
    Core-->>Store: Response Token List
    deactivate Core
    Store-->>USER: Deliver Token List
    deactivate Store
Last updated: 2026-04-24 07:45:12 © 2026 LG Electronics Inc. All rights reserved.