Skip to main content

​
APTOS

​
Aptos Cross-Chain SDK

The Aptos blockchain uses the Move programming language and provides a powerful environment for smart contracts and decentralized applications. The Demos Network SDK provides seamless integration with Aptos through our XM (Cross-chain Messaging) architecture.

​
Key Concepts

Demos Network Architecture: Payment and contract operations go through Demos, ensuring network participation and cross-chain compatibility. This relay-first approach provides enhanced security and enables true cross-chain functionality. Move Language: Aptos uses Move, a resource-oriented programming language where smart contracts are organized as modules deployed at specific addresses. Type Arguments: Many Move functions require explicit type arguments, especially when working with generic types like coins.

​
Installation

bun add @kynesyslabs/demosdk@latest @aptos-labs/ts-sdk

​
Quick Start

import { Network } from '@aptos-labs/ts-sdk'
import { APTOS } from '@kynesyslabs/demosdk/xmcore'

// Initialize with network
const aptos = new APTOS("", Network.DEVNET)
// Using a custom RPC endpoint
// new APTOS("https://custom-aptos-rpc.com", Network.DEVNET)
await aptos.connect()

// Connect wallet
const privateKey = "0x..." // Your private key
await aptos.connectWallet(privateKey)

​
Balance Queries

You can get the coin balance as shown below: 
// Get APT balance
const balance = await aptos.getBalance(address)
console.log("APT balance", balance)

// Get specific coin balance
const coinBalance = await aptos.getCoinBalance("0x1::aptos_coin::AptosCoin", address)
console.log("AptosCoin balance", coinBalance)

​
Token Transfer

You can make payments on Aptos via Demos as shown below. Please check out the authentication docs on how to interact with the Demos network using the Demos object. 
import { XMScript } from "@kynesyslabs/demosdk/types"
import { prepareXMPayload } from "@kynesyslabs/demosdk/websdk"

const recipient = "0x..."

// Amount in octa (1 APT = 100,000,000 Octas)
const amount = "3000"

// Get the signed tx as hex string
const tx = aptos.preparePay(recipient, amount)

// Broadcast the tx
const payload: XMScript = {
    operations: {
        aptos_pay: {
            chain: "aptos",
            subchain: "devnet",
            is_evm: false,
            rpc: null,
            task: {
                signedPayloads: [tx],
                params: null,
                type: "pay",
            }
        }
    },
    operations_order: ["aptos_pay"],
}

// Create the Demos tx
const tx = await prepareXMPayload(payload, demos)
console.log("tx", tx)

// Validate Demos tx
const validityData = await demos.confirm(tx)
console.log("validityData", validityData)
 
// Broadcast
const res = await demos.broadcast(validityData)
console.log("res", JSON.stringify(res, null, 2))
When working with Aptos browser extensions use their documentation to create and sign the transaction. Here is some documentation: Once you have the signed transaction as a Uint8Array, convert it into hex and use that to create the XMScript from the previous code sample: For Martian wallet, that would look like this: 
import { hexToUint8Array } from "@kynesyslabs/demosdk/encryption"

const txBuffer = await window.martian.signTransaction(transaction)
const txHex = uint8ArrayToHex(txBuffer)

const payload: XMScript = {
    operations: {
        aptos_pay: {
            chain: "aptos",
            subchain: "devnet",
            is_evm: false,
            rpc: null,
            task: {
                signedPayloads: [txHex],
                params: [],
                type: "pay",
            }
        }
    },
    operations_order: ["aptos_pay"],
}

// Proceed to create Demos tx, validate and broadcast

​
Smart Contract Interactions

​
Reading from Contracts

You can read from a contract on Aptos via Demos as shown: 
// Read the "name" property of a contract
const payload = await instance.readFromContract(
    "0x1",
    "coin",
    "name",
    [],
    ["0x1::aptos_coin::AptosCoin"]
)

// Create Demos tx
const tx = await prepareXMPayload(payload, demos)
console.log("tx", tx)

// Validate Demos tx
const validityData = await demos.confirm(tx)
console.log("validityData", validityData)

// Broadcast
const res = await demos.broadcast(validityData)
console.log("res", JSON.stringify(res, null, 2))

​
Writing to Contracts

You can write to a contract on Aptos via Demos as shown: 
// Write to the "transfer" method on a contract
const payload = await instance.writeToContract(
    "0x1",                                 // module address
    "coin",                                // module name
    "transfer",                            // function name
    [testAddress, "1000"],                 // args: [recipient, amount]
    ["0x1::aptos_coin::AptosCoin"]         // typeArguments: coin type
)
console.log("xmscript", xmscript)

// Create Demos tx
const tx = await prepareXMPayload(payload, demos)
console.log("tx", tx)

// Validate Demos tx
const validityData = await demos.confirm(tx)
console.log("validityData", validityData)

// Broadcast
const res = await demos.broadcast(validityData)
console.log("res", JSON.stringify(res, null, 2))

​
Signing and Verifying Messages

You can sign and verify messages using the connected Aptos wallet as shown: 
// Sign message
const signature = await aptos.signMessage("Hello Demos Network")

// Verify message signature
const publicKey = aptos.getPublicKey()
const isVerified = await aptos.verifyMessage(message, signature, publicKey)
When working with browser wallet extensions, use their documentation to sign the message: The signMessage method provided by the injected provider returns an object with a fullMessage property which you can use to verify the message as follows: For Martian wallet, that looks like this: 
const { fullMessage, signature } = await window.martian.signMessage({
    message,
    nonce,
})

// Verify using the Demos Aptos SDK
const isVerified = aptos.verifyMessage(fullMessage, signature, publicKey)

​
Utility Methods

// Get wallet address
const address = aptos.getAddress()

// Validate Aptos address
const isValid = aptos.isAddress("0x1")

// Wait for transaction confirmation
const txResponse = await aptos.waitForTransaction(txHash)