Custom Data

This guide explains how to implement custom data functionality using the Cross SDK, including both signature and transaction features.

Signature with Custom Data

1. Sign Custom Data

import { useAppKitAccount, ConnectionController } from '@to-nexus/sdk/react'

async function handleSignMessage() {
  const account = useAppKitAccount()
  if (!account?.isConnected) return

  const signedMessage = await ConnectionController.signMessage({ 
    message: `Hello, world! ${Date.now()}`,
    customData: {
      metadata: "This is metadata for signed message"
    }
  })
}

2. Plain Text

import { useAppKitAccount, ConnectionController } from '@to-nexus/sdk/react'

async function handleSignMessage() {
  const account = useAppKitAccount()
  if (!account?.isConnected) return

  const signedMessage = await ConnectionController.signMessage({ 
    message: `Hello, world! ${Date.now()}`,
    customData: {
      metadata: "This is a plain text message for signature"
    }
  })
}

3. JSON Data

import { useAppKitAccount, ConnectionController } from '@to-nexus/sdk/react'

async function handleSignMessage() {
  const account = useAppKitAccount()
  if (!account?.isConnected) return

  const signedMessage = await ConnectionController.signMessage({ 
    message: `Hello, world! ${Date.now()}`,
    customData: {
      metadata: JSON.stringify({
        type: "signature",
        purpose: "authentication",
        timestamp: new Date().toISOString()
      })
    }
  })
}

4. Binary Data

import { useAppKitAccount, ConnectionController } from '@to-nexus/sdk/react'

async function handleSignMessage() {
  const account = useAppKitAccount()
  if (!account?.isConnected) return

  const binaryData = new TextEncoder().encode("Binary data for signature")
  
  const signedMessage = await ConnectionController.signMessage({ 
    message: `Hello, world! ${Date.now()}`,
    customData: {
      metadata: binaryData,
      format: "binary"
    }
  })
}

Transaction with Custom Data

1. Plain Text

import { useAppKitAccount, SendController } from '@to-nexus/sdk/react'

async function handleSendNative() {
  const account = useAppKitAccount()
  if (!account?.isConnected) return

  const resTx = await SendController.sendNativeToken({
    receiverAddress: RECEIVER_ADDRESS,
    sendTokenAmount: 1,
    decimals: '18',
    customData: {
      metadata: "You are about to send 1 CROSS to the receiver address. This is plain text formatted custom data."
    }
  })
}

2. JSON Data

import { useAppKitAccount, SendController } from '@to-nexus/sdk/react'

async function handleSendTransaction() {
  const account = useAppKitAccount()
  if (!account?.isConnected) return

  const resTx = await SendController.sendNativeToken({
    receiverAddress: RECEIVER_ADDRESS,
    sendTokenAmount: 1,
    decimals: '18',
    customData: {
      metadata: JSON.stringify({
        type: "payment",
        description: "Monthly subscription",
        reference: "SUB-2024-03",
        amount: 1,
        currency: "CROSS"
      })
    }
  })
}

3. Binary Data

import { useAppKitAccount, SendController } from '@to-nexus/sdk/react'

async function handleSendTransaction() {
  const account = useAppKitAccount()
  if (!account?.isConnected) return

  const binaryData = new TextEncoder().encode("Binary data example")
  
  const resTx = await SendController.sendNativeToken({
    receiverAddress: RECEIVER_ADDRESS,
    sendTokenAmount: 1,
    decimals: '18',
    customData: {
      metadata: binaryData,
      format: "binary"
    }
  })
}

Read Custom Data

1. Read Transaction Data

import { ConnectionController } from '@to-nexus/sdk/react'

async function readCustomData(txHash: string) {
  const tx = await ConnectionController.getTransaction(txHash)
  
  if (tx.customData?.format === "binary") {
    // Handle binary data
    const decoder = new TextDecoder()
    return decoder.decode(tx.customData.metadata)
  }
  
  if (tx.customData?.metadata) {
    try {
      // Try parsing as JSON
      return JSON.parse(tx.customData.metadata)
    } catch {
      // Return as plain text if not JSON
      return tx.customData.metadata
    }
  }
  
  return null
}