@mcintyre94/transactions

@solana/transactions

This package contains types and functions for creating transactions. It can be used standalone, but it is also exported as part of the Solana JavaScript SDK @solana/web3.js@experimental.

Transactions are built one step at a time using the transform functions offered by this package. To make it more ergonmic to apply consecutive transforms to your transactions, consider using a pipelining helper like the one in @solana/functional.

import { pipe } from '@solana/functional';
import {
    appendTransactionInstruction,
    setTransactionFeePayer,
    setTransactionLifetimeUsingBlockhash,
} from '@solana/transactions';

const transferTransaction = pipe(
    createTransaction({ version: 0 }),
    tx => setTransactionFeePayer(myAddress, tx),
    tx => setTransactionLifetimeUsingBlockhash(latestBlockhash, tx),
    tx => appendTransactionInstruction(createTransferInstruction(myAddress, toAddress, amountInLamports), tx)
);

Creating transactions

Types

TransactionVersion

As Solana transactions acquire more capabilities their version will advance. This type is a union of all possible transaction versions.

Functions

createTransaction()

Given a TransactionVersion this method will return an empty transaction having the capabilities of that version.

import { createTransaction } from '@solana/transactions';

const tx = createTransaction({ version: 0 });

Setting the fee payer

Types

ITransactionWithFeePayer

This type represents a transaction for which a fee payer has been declared. A transaction must conform to this type to be landed on the network.

Functions

setTransactionFeePayer()

Given a base58-encoded address of a system account, this method will return a new transaction having the same type as the one supplied plus the ITransactionWithFeePayer type.

import { address } from '@solana/addresses';
import { setTransactionFeePayer } from '@solana/transactions';

const myAddress = address('mpngsFd4tmbUfzDYJayjKZwZcaR7aWb2793J6grLsGu');
const txPaidByMe = setTransactionFeePayer(myAddress, tx);

Defining a transaction's lifetime

A signed transaction can be only be landed on the network if certain conditions are met:

• It includes the hash of a recent block
• It includes the value of an unused nonce known to the network

These conditions define a transaction's lifetime, after which it can no longer be landed, even if signed.

Types

ITransactionWithBlockhashLifetime

This type represents a transaction whose lifetime is defined by the age of the blockhash it includes. Such a transaction can only be landed on the network if the current block height of the network is less than or equal to the value of ITransactionWithBlockhashLifetime['lifetimeConstraint']['lastValidBlockHeight'].

IDurableNonceTransaction

This type represents a transaction whose lifetime is defined by the value of a nonce it includes. Such a transaction can only be landed on the network if the nonce is known to the network and has not already been used to land a different transaction.

Blockhash

This type represents a string that is particularly known to be the base58-encoded value of a block.

Nonce

This type represents a string that is particularly known to be the base58-encoded value of a nonce.

Functions

setTransactionLifetimeUsingBlockhash()

Given a blockhash and the last block height at which that blockhash is considered usable to land transactions, this method will return a new transaction having the same type as the one supplied plus the ITransactionWithBlockhashLifetime type.

import { setTransactionLifetimeUsingBlockhash } from '@solana/transactions';

const { value: latestBlockhash } = await rpc.getLatestBlockhash().send();
const txWithBlockhashLifetime = setTransactionLifetimeUsingBlockhash(latestBlockhash, tx);

setTransactionLifetimeUsingDurableNonce()

Given a nonce, the account where the value of the nonce is stored, and the address of the account authorized to consume that nonce, this method will return a new transaction having the same type as the one supplied plus the IDurableNonceTransaction type. In particular, this method prepends an instruction to the transaction designed to consume (or ‘advance’) the nonce in the same transaction whose lifetime is defined by it.

import { setTransactionLifetimeUsingDurableNonce } from '@solana/transactions';

const NONCE_VALUE_OFFSET =
    4 + // version(u32)
    4 + // state(u32)
    32; // nonce authority(pubkey)
// Then comes the nonce value.

const nonceAccountAddress = address('EGtMh4yvXswwHhwVhyPxGrVV2TkLTgUqGodbATEPvojZ');
const nonceAuthorityAddress = address('4KD1Rdrd89NG7XbzW3xsX9Aqnx2EExJvExiNme6g9iAT');
const { value: nonceAccount } = await rpc
    .getAccountInfo(nonceAccountAddress, {
        dataSlice: { length: 32, offset: NONCE_VALUE_OFFSET },
        encoding: 'base58',
    })
    .send();
const nonce =
    // This works because we asked for the exact slice of data representing the nonce
    // value, and furthermore asked for it in `base58` encoding.
    nonceAccount!.data[0] as unknown as Nonce;

const durableNonceTransaction = setTransactionLifetimeUsingDurableNonce(
    { nonce, nonceAccountAddress, nonceAuthorityAddress },
    tx
);

assertIsBlockhash()

Client applications primarily deal with blockhashes in the form of base58-encoded strings. Blockhashes returned from the RPC API conform to the type Blockhash. You can use a value of that type wherever a blockhash is expected.

From time to time you might acquire a string, that you expect to validate as a blockhash, from an untrusted network API or user input. To assert that such an arbitrary string is a base58-encoded blockhash, use the assertIsBlockhash function.

import { assertIsBlockhash } from '@solana/transactions';

// Imagine a function that asserts whether a user-supplied blockhash is valid or not.
function handleSubmit() {
    // We know only that what the user typed conforms to the `string` type.
    const blockhash: string = blockhashInput.value;
    try {
        // If this type assertion function doesn't throw, then
        // Typescript will upcast `blockhash` to `Blockhash`.
        assertIsBlockhash(blockhash);
        // At this point, `blockhash` is a `Blockhash` that can be used with the RPC.
        const blockhashIsValid = await rpc.isBlockhashValid(blockhash).send();
    } catch (e) {
        // `blockhash` turned out not to be a base58-encoded blockhash
    }
}

assertIsDurableNonceTransaction()

From time to time you might acquire a transaction that you expect to be a durable nonce transaction, from an untrusted network API or user input. To assert that such an arbitrary transaction is in fact a durable nonce transaction, use the assertIsDurableNonceTransaction function.

See assertIsBlockhash() for an example of how to use an assertion function.

Adding instructions to a transaction

Types

IInstruction

This type represents an instruction to be issued to a program. Objects that conform to this type have a programAddress property that is the base58-encoded address of the program in question.

IInstructionWithAccounts

This type represents an instruction that specifies a list of accounts that a program may read from, write to, or require be signers of the transaction itself. Objects that conform to this type have an accounts property that is an array of IAccountMeta | IAccountLookupMeta in the order the instruction requires.

IInstructionWithData

This type represents an instruction that supplies some data as input to the program. Objects that conform to this type have a data property that can be any type of Uint8Array.

Functions

appendTransactionInstruction()

Given an instruction, this method will return a new transaction with that instruction having been added to the end of the list of existing instructions.

import { address } from '@solana/addresses';
import { appendTransactionInstruction } from '@solana/transactions';

const memoTransaction = appendTransactionInstruction(
    {
        data: new TextEncoder().encode('Hello world!'),
        programAddress: address('MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr'),
    },
    tx
);

prependTransactionInstruction()

Given an instruction, this method will return a new transaction with that instruction having been added to the beginning of the list of existing instructions.

See appendTransactionInstruction() for an example of how to use this function.

Signing transactions

In order to be landed on the network, a transaction must be signed by all of the private keys belonging to accounts that are required signers of the transaction.

Whether a transaction is ready to be signed or not is enforced for you at the type level. In order to be signable, a transaction must:

• have a version and a list of zero or more instructions (ie. conform to BaseTransaction)
• have a fee payer set (ie. conform to ITransactionWithFeePayer)
• have a lifetime specified (ie. conform to ITransactionWithBlockhashLifetime | IDurableNonceTransaction)

Types

ITransactionWithSignatures

This type represents a transaction that is signed by at least one of its required signers. This type of transaction can be serialized to wire format, but is unsuitable for use with functions designed to land transaction on the network.

Expect any function that modifies a transaction (eg. setTransactionFeePayer, appendTransactionInstruction, et cetera) to delete a transaction's signatures property and unset this type.

IFullySignedTransaction

This type represents a transaction that is signed by all of its required signers. Being fully signed is a prerequisite of functions designed to land transactions on the network.

Expect any function that modifies a transaction (eg. setTransactionFeePayer, appendTransactionInstruction, et cetera) to delete a transaction's signatures property and unset this type.

Functions

getSignatureFromTransaction()

Given a transaction signed by its fee payer, this method will return the Signature that uniquely identifies it. This string can be used to look up transactions at a later date, for example on a Solana block explorer.

import { getSignatureFromTransaction } from '@solana/transactions';

const signature = getSignatureFromTransaction(tx);
console.debug(`Inspect this transaction at https://explorer.solana.com/tx/${signature}`);

signTransaction()

Given an array of CryptoKey objects which are private keys pertaining to addresses that are required to sign a transaction, this method will return a new signed transaction having the same type as the one supplied plus the ITransactionWithSignatures type.

import { generateKeyPair } from '@solana/keys';
import { signTransaction } from '@solana/transactions';

const signedTransaction = await signTransaction([myPrivateKey], tx);

Serializing transactions

Before sending a transaction to be landed on the network, you must serialize it in a particular way. You can use these types and functions to serialize a signed transaction into a binary format suitable for transit over the wire.

Types

Base64EncodedWireTransaction

This type represents the wire format of a transaction as a base64-encoded string.

Functions

getBase64EncodedWireTransaction()

Given a signed transaction, this method returns the transaction as a string that conforms to the Base64EncodedWireTransaction type.

import { getBase64EncodedWireTransaction, signTransaction } from '@solana/transactions';

const serializedTransaction = getBase64EncodedWireTransaction(signedTransaction);
const signature = await rpc.sendTransaction(serializedTransaction, { encoding: 'base64' }).send();