Data Models

This document provides a comprehensive overview of the data structures used throughout the Mesh Connect Android SDK. These models define the structure for all communication between the web-based financial flows and the native Android application, including authentication tokens, account information, transfer results, and error handling.

For detailed information about transfer-specific data structures, see Transfer Payloads. For authentication-related models, see Authentication Payloads. For JSON conversion mechanisms, see JSON Serialization and Deserialization.

Payload Hierarchy

The SDK uses a sealed interface hierarchy to ensure type safety and exhaustive handling of all possible payload types. All payload classes implement Android's Parcelable interface for efficient inter-process communication.

«sealed interface»
LinkPayload
+Parcelable
«sealed interface»
TransferFinishedPayload
AccessTokenPayload
+List<AccountToken> accountTokens
+String brokerType
+String brokerName
+BrandInfo brokerBrandInfo
+Int? expiresInSeconds
+Int? refreshTokenExpiresInSeconds
DelayedAuthPayload
+Int? refreshTokenExpiresInSeconds
+String brokerType
+String refreshToken
+String brokerName
+BrandInfo brokerBrandInfo
TransferFinishedSuccessPayload
+String txId
+String fromAddress
+String toAddress
+String symbol
+Double amount
+String networkId
+Double? amountInFiat
+Double? totalAmountInFiat
+String? networkName
+String? txHash
+String? transferId
+String? refundAddress
TransferFinishedErrorPayload
+String errorMessage

Sources: link/src/main/java/com/meshconnect/link/entity/LinkPayload.kt6-84

Account and Token Models

The SDK defines several interconnected models for handling account information and access tokens from financial brokers.

AccountToken Structure

AccountToken
+Account account
+String accessToken
+String? refreshToken
Account
+String accountId
+String accountName
+String frontAccountId
+Double? fund
+Double? cash
+Boolean? isReconnected
BrandInfo
+String? brokerLogo
+String? brokerPrimaryColor
+String? logoLightUrl
+String? logoDarkUrl
+String? iconLightUrl
+String? iconDarkUrl
AccessTokenPayload
+List<AccountToken> accountTokens
+BrandInfo brokerBrandInfo

The AccountToken class link/src/main/java/com/meshconnect/link/entity/LinkPayload.kt24-28 encapsulates both account metadata and authentication credentials. Each token contains:

• account: Complete account information including balances and identifiers
• accessToken: Bearer token for API authentication
• refreshToken: Optional token for refreshing expired access tokens

Sources: link/src/main/java/com/meshconnect/link/entity/LinkPayload.kt24-48

Response Wrapper Models

The SDK uses internal response wrapper classes to handle the JSON structure received from the web layer:

These wrapper classes link/src/main/java/com/meshconnect/link/entity/Response.kt3-13 provide a consistent JSON deserialization structure where the actual payload data is nested under a payload field.

Sources: link/src/main/java/com/meshconnect/link/entity/Response.kt3-13

Transfer Result Models

Transfer operations can result in either success or error outcomes, both implementing the TransferFinishedPayload sealed interface.

Transfer Success Data

Optional Fields
amountInFiat: Double?   // USD equivalent amount

amount: Double           // Transfer amount

The success payload link/src/main/java/com/meshconnect/link/entity/LinkPayload.kt66-79 contains comprehensive transfer details, with several optional fields that may not be present depending on the transfer type and blockchain network.

Sources: link/src/main/java/com/meshconnect/link/entity/LinkPayload.kt66-84

JSON Mapping and Serialization

The SDK handles JSON-to-object conversion automatically using custom deserializers. The test files demonstrate the expected JSON structure:

Transfer Success JSON Structure

{
    "status": "success",
    "txId": "234sdf-xxx3902",
    "fromAddress": "0923xxx",
    "toAddress": "92811yyyy",
    "symbol": "UST",
    "amount": 1.0024,
    "networkId": "79823981e",
    "amountInFiat": 10.55,
    "totalAmountInFiat": 11.2,
    "networkName": "Polygon",
    "txHash": "1-9340-194350432-21123232",
    "transferId": "0x093547892-24234-2342",
    "refundAddress": "test-refund-address"
}

The SDK supports flexible JSON parsing where optional fields can be omitted link/src/test/resources/transfer-success-empty-fields.json1-7 and the deserializer will properly handle null values and empty strings.

Sources: link/src/test/kotlin/com/meshconnect/link/converter/TransferFinishedPayloadDeserializerTest.kt14-67 link/src/test/resources/transfer-success.json1-15 link/src/test/resources/transfer-success-empty-fields.json1-7

Data Model Usage Patterns

All payload classes are designed as immutable data classes with the following characteristics:

• Parcelable Implementation: All models can be passed between Android components efficiently
• Null Safety: Optional fields use Kotlin's nullable types (?) for explicit null handling
• Sealed Interfaces: Exhaustive when expressions ensure all payload types are handled
• JSON Compatibility: Direct mapping between JSON properties and Kotlin properties

The models support Android's configuration changes and process recreation through the @Parcelize annotation, ensuring data persistence across the application lifecycle.

Sources: link/src/main/java/com/meshconnect/link/entity/LinkPayload.kt3-4 link/src/test/kotlin/com/meshconnect/link/entity/TransferFinishedSuccessPayloadTest.kt8-36