Web3 Core

Multiplatform Web3 Library

⚠️ Experimental

This library is still under development. The library is functional and being used downstream by the likes of SolanaKMP. Breaking changes may will be added leading up to a v1.0 API. You have been warned.

Usage

Solana

Build a Transaction

// Solana Memo Program 
val account = SolanaPublicKey(keyPair.publicKey)
val memoProgramId = SolanaPublicKey.from("MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr")
val memoInstruction = TransactionInstruction(
    memoProgramId,
    listOf(AccountMeta(account, true, true)),
    "hello world ".encodeToByteArray()
)

// Build Message
val blockhash = Blockhash(getRecentBlockhash())
val message = Message.Builder()
    .addInstruction(memoInstruction)
    .setRecentBlockhash(blockhash)
    .build()

Prepare a Signer

using Diglol Crypto library for ED25519 signing:

// prepare signer
val keyPair = Ed25519.generateKeyPair()
val signer = object : Ed25519Signer() {
    override val publicKey: ByteArray get() = keyPair.publicKey
    override suspend fun signPayload(payload: ByteArray): ByteArray = Ed25519.sign(keyPair, payload)
}

Sign Message & Build Transaction

// Sign Message
val signature = signer.signPayload(message.serialize())

// Build Transaction
val transaction = Transaction(listOf(signature), message)

Send Transaction to RPC

Using Base58 encoding from MultiMult and Solana RPC driver from RpcCore

// serialize transaction
val transactionBytes = transaction.serialize()
val encodedTransaction = Base58.encodeToString(transactionBytes)

// setup RPC driver
val rpcUrl = "https://api.endpoint.com"
val rpcDriver = Rpc20Driver(rpcUrl, MyNetworkDriver())

class SendTransactionRequest(encodedTransaction: String, requestId: String)
    : JsonRpc20Request(
        method = "sendTransaction",
        params = buildJsonArray {
            add(encodedTransaction)
        },
        requestId
    )

// build rpc request
val requestId = 1
val rpcRequest = SendTransactionRequest(encodedTransaction, requestId)

// send the request and get response
// using JsonElement.serializer() will return the JSON RPC response. you can use your own serializer to get back a specific object
val rpcResponse = rpcDriver.makeRequest(rpcRequest, JsonElement.serializer())

Initiate an SPL Transfer with ATAs

// gather public keys
val mint = SolanaPublicKey(/* public key of the token mint you want to transfer */)
val senderPublicKey = SolanaPublicKey(/* sender's public key */)
val receiverPublicKey = SolanaPublicKey(/* receiver's public key */)

// calculate ATAs for sender and receiver
// Note: these accounts must already exist
val senderTokenAccount = = SolanaPublicKey(ProgramDerivedAddress.find(
    listOf(senderPublicKey.bytes, TokenProgram.PROGRAM_ID.bytes, mint.bytes),
    AssociatedTokenProgram.PROGRAM_ID
).getOrThrow().bytes)

val receiverTokenAccount = = SolanaPublicKey(ProgramDerivedAddress.find(
    listOf(receiverPublicKey.bytes, TokenProgram.PROGRAM_ID.bytes, mint.bytes),
    AssociatedTokenProgram.PROGRAM_ID
).getOrThrow().bytes)

val transferMessage = Message.Builder()
    .setRecentBlockhash(recentBlockhash)
    .addInstruction(TokenProgram.transferChecked(
        senderTokenAccount,
        receiverTokenAccount,
        10_000_000, // amount to transfer
        6, // decimals
        senderPublicKey,
        mint
    ))
    .build()

val signature = ... // sign transaction using web3-core Signer or other mechanism 
val transferTransaction = Transaction(listOf(signature), transferMessage.serialize())

// Send transaction to cluster (using rpc-solana here)
rpc.sendAndConfirmTransaction(
    transferTransaction, 
    TransactionOptions(commitment = Commitment.CONFIRMED)
)