Architecture

Through the CROSS Ramp Console (RAMP), you can intuitively check not only the request-response flow between applications (dApps) and servers, but also the token issuance process linked to the blockchain network.

Developers can follow step-by-step how dApps interact with CROSS Ramp, simplifying the entire process, from the transmission of token issuance requests to actual token creation on the blockchain.

Components

Component	Role / Description
RAMP F/E	Provides user interface (UI) and displays transaction status in real-time.
RAMP B/E	Performs core logic including transaction request processing, validation, and Validator signature requests.
Game Client	Calls RAMP F/E and displays transaction progress status.
Game Server	Handles game internal logic including game asset verification, deduction and restoration, and signature processing.
Blockchain Network	Processes actual token minting and burning transactions.

Token Minting

Flow Diagram

sequenceDiagram
    box Application(Dapp)
    participant U as User/Client
    participant GS as Game Server
    end

    box RAMP-Platform
    participant RFE as RAMP F/E
    participant RBE as RAMP B/E
    end
    participant BC as Blockchain Network
    
    %% Entry
    
    U->>U: 1. Click Token Minting
    activate U

    U->>GS:JWT 2. Token Request
    activate U
    activate GS
    GS-->>U:JWT Token Response
    deactivate U
    deactivate GS
    U->>RFE: 3. Open WebView (Project ID, JWT, Character Info)
    activate U
    activate RFE
    RFE->>RBE: 4. Game Asset Info Request
    activate RFE
    activate RBE
    RBE->>GS:5. Game Asset Info Request
    activate RBE
    activate GS
    GS-->>RBE:Game Asset Info Response
    deactivate RBE
    deactivate GS
    

    RBE-->>RFE:Game Asset Info Response
    deactivate RFE
    deactivate RBE
    RFE-->>U:Game Asset Query Response
    deactivate U
    deactivate RFE


    U->>RFE: 6. Select Minting Quantity and Sign
    activate U
    activate RFE
    RFE->>RBE: 7. Transfer User Signature Value
    activate RFE
    activate RBE
    
    RBE->>GS: 8. Validator Signature Request
    activate GS
    activate RBE
    GS->>GS: 9. User Request Verification and Game Asset Processing
    GS->>GS: 10. Validator Signature
    GS-->>RBE: Validator Signature Response
    deactivate GS
    deactivate RBE
    RBE->>RBE: 11. Validator Signature Verification
    RBE->>BC: 12. Transaction Request
    activate RBE
    activate BC
    BC-->>RBE: Transaction Result Response
    deactivate BC
    deactivate RBE
    RBE-->>RFE: Transaction Result Response
    deactivate RFE
    
    RBE-)GS: 13. Transaction Result Delivery (Webhook)
    activate RBE
    activate GS
    
    opt Fail
    GS->>GS: 14. Game Asset Processing<br/>(On Minting Failure)
    end
    GS--)RBE: Transaction Result Receipt Response
    
    deactivate RBE
    deactivate GS
    
    deactivate RBE
    
    RFE-->>U: Minting Result Response

    deactivate RFE
    deactivate U

    U ->> U: 15. UI Processing

    deactivate U

Flow Diagram Description

Click Token Minting
- User clicks the minting button within the application (dApp).

JWT Token Request
- Authentication token is required for communication between RAMP (B/E) and game server.
- Used when RAMP B/E requests user's game asset information from the game server, and the game server needs to verify the token.

Open WebView
- Load the RAMP F/E page from the application (dApp), including the ProjectID created in the RAMP console.
- The previously created JWT and session ID (user character information) values must be included in the request parameters.
- Use WebView in mobile environments and load the RAMP F/E page through the system default browser in desktop environments.

https://ramp.crosstoken.io/catalog?
projectId={{Your Project ID}}
&sessionId={{dappSessionId}}
&accessToken={{dappAccessToken}}
&platform=web
&network=mainnet

Game Asset Info Request
- RAMP F/E requests user's game asset information from RAMP B/E.

Game Asset Info Request
- RAMP B/E requests user's game asset information from the game server.
- Game asset requests are sent to the URL registered in RAMP's 'Get Assets' item.
- JWT is included in the HTTP Request Header, so the game server must verify the JWT.

Select Minting Quantity and Sign
- User directly inputs the quantity to mint and proceeds with signing through the CROSS wallet in RAMP F/E.

Transfer User Signature Value
- RAMP F/E sends the user's signature value to RAMP B/E.

Validator Signature Request
- RAMP B/E sends a Validator signature request to the game server.
- The HTTP Request Header of the RAMP B/E request includes a signature value generated using HMAC, created in the CROSS Ramp Console.
  The game server must verify this signature value to confirm the integrity of the request.
- Validator signature requests are sent to the URL registered in the CROSS Ramp Console's 'Validator Order' item.
- The CROSS Ramp Console requires registration of addresses, generated with tools provided by NEXUS.
- The game server must perform EC signatures using private keys, generated with tools provided by NEXUS.

⚠️
Important
Private keys generated using tools provided by Nexus must be thoroughly managed to prevent external exposure.

User Request Verification and Game Asset Processing
- The game server must verify the validity of game assets used for token issuance based on data received from RAMP B/E.
- After deducting the game assets required for token issuance from the user account, proceed with the Validator signature and response procedures in step 10.

Validator Signature
- The game server must perform ECDSA signature using the 'digest' value from the Validator request data received from RAMP B/E.

Validator Signature Verification
- RAMP B/E verifies whether the response sent by the game server is correct using the Validator signature value responded by the game server.
Transaction Request
- When Validator verification succeeds in step 11, request token minting/burning transactions to the blockchain network.

Transaction Result Delivery (Webhook)
- Deliver transaction results from the blockchain network to the game server.
- The HTTP Request Header of the RAMP B/E request includes a signature value generated using HMAC created in the RAMP console.
  The game server must verify this signature value to confirm the integrity of the request.

Game Asset Processing
- If the transaction fails in the blockchain network, the game server must restore the user's game assets deducted in step 9.

UI Processing
- The RAMP F/E UI is automatically updated according to the transaction result status.

Token Burning

Flow Diagram

sequenceDiagram
    box Application(Dapp)
    participant U as User/Client
    participant GS as Game Server
    end

    box RAMP-Platform
    participant RFE as RAMP F/E
    participant RBE as RAMP B/E
    end
    participant BC as Blockchain Network
    
    %% Entry
    
    U->>U: 1. Click Token Burn
    activate U

    U->>GS:JWT 2. Token Request
    activate U
    activate GS
    GS-->>U:JWT Token Response
    deactivate U
    deactivate GS
    U->>RFE: 3. Open WebView (Project ID, JWT, Character Info)
    activate U
    activate RFE
    RFE->>RBE: 4. Game Asset Info Request
    activate RFE
    activate RBE
    RBE->>GS:5. Game Asset Info Request
    activate RBE
    activate GS
    GS-->>RBE:Game Asset Info Response
    deactivate RBE
    deactivate GS
    

    RBE-->>RFE:Game Asset Info Response
    deactivate RFE
    deactivate RBE
    RFE-->>U:Game Asset Query Response
    deactivate U
    deactivate RFE


    U->>RFE: 6. Select Burn Quantity and Sign
    activate U
    activate RFE
    RFE->>RBE: 7. Transfer User Signature Value
    activate RFE
    activate RBE
    
    RBE->>GS: 8. Validator Signature Request
    activate GS
    activate RBE
    GS->>GS: 9. User Request Verification
    GS->>GS: 10. Validator Signature
    GS-->>RBE: Validator Signature Response
    deactivate GS
    deactivate RBE
    RBE->>RBE: 11. Validator Signature Verification
    RBE->>BC: 12. Transaction Request
    activate RBE
    activate BC
    BC-->>RBE: Transaction Result Response
    deactivate BC
    deactivate RBE
    RBE-->>RFE: Transaction Result Response
    deactivate RFE
    
    RBE-)GS: 13. Transaction Result Delivery (Webhook)
    activate RBE
    activate GS
    
    opt Success
    GS->>GS: 14. Game Asset Processing<br/>(On Burn Success)
    end
    GS--)RBE: Transaction Result Receipt Response
    
    deactivate RBE
    deactivate GS
    
    deactivate RBE
    
    RFE-->>U: Burn Result Response

    deactivate RFE
    deactivate U

    U ->> U: 15. UI Processing

    deactivate U

Flow Diagram Description

The flow up to the user's game asset inquiry is the same as token minting, so please refer to the token minting section.

User Request Verification

The game server must verify the validity of game assets to be given to the user after token burning, based on data received from RAMP B/E.
Unlike token minting, game assets should be given to users only after the token burning transaction succeeds in the blockchain network.

Game Asset Processing

When the transaction succeeds in the blockchain network, the game server must give game assets to the user.