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@solana/transaction-messages

This package contains types and functions for creating transaction messages. It can be used standalone, but it is also exported as part of Kit @solana/kit.

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

``ts
import { pipe } from '@solana/functional';
import {
appendTransactionMessageInstruction,
createTransactionMessage,
setTransactionMessageFeePayer,
setTransactionMessageLifetimeUsingBlockhash,
} from '@solana/transaction-messages';

const transferTransactionMessage = pipe(
createTransactionMessage({ version: 0 }),
m => setTransactionMessageFeePayer(myAddress, m),
m => setTransactionMessageLifetimeUsingBlockhash(latestBlockhash, m),
m => appendTransactionMessageInstruction(getTransferSolInstruction({ source, destination, amount }), m),
);
`

Creating transaction messages

$3

#### TransactionVersion

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

$3

#### createTransactionMessage()

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

`ts
import { createTransactionMessage } from '@solana/transaction-messages';

const message = createTransactionMessage({ version: 0 });
`

Setting the fee payer

$3

#### TransactionMessageWithFeePayer

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

$3

#### setTransactionMessageFeePayer()

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

`ts
import { address } from '@solana/addresses';
import { setTransactionMessageFeePayer } from '@solana/transaction-messages';

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

Defining a transaction message'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
- Or 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. The lifetime must be added to the transaction message before it is compiled to be sent.

$3

#### TransactionMessageWithBlockhashLifetime

This type represents a transaction message 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 TransactionMessageWithBlockhashLifetime['lifetimeConstraint']['lastValidBlockHeight'].

#### TransactionMessageWithDurableNonceLifetime

This type represents a transaction message 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.

$3

#### setTransactionMessageLifetimeUsingBlockhash()

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 message having the same type as the one supplied plus the TransactionMessageWithBlockhashLifetime type.

`ts
import { setTransactionMessageLifetimeUsingBlockhash } from '@solana/transaction-messages';

const { value: latestBlockhash } = await rpc.getLatestBlockhash().send();
const txMessageWithBlockhashLifetime = setTransactionMessageLifetimeUsingBlockhash(latestBlockhash, txMessage);
`

#### setTransactionMessageLifetimeUsingDurableNonce()

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 TransactionMessageWithDurableNonceLifetime type. In particular, this method _prepends_ an instruction to the transaction message designed to consume (or ‘advance’) the nonce in the same transaction whose lifetime is defined by it.

`ts
import { Nonce, setTransactionMessageLifetimeUsingDurableNonce } from '@solana/transaction-messages';
import { fetchNonce } from '@solana-program/system';

const nonceAccountAddress = address('EGtMh4yvXswwHhwVhyPxGrVV2TkLTgUqGodbATEPvojZ');
const nonceAuthorityAddress = address('4KD1Rdrd89NG7XbzW3xsX9Aqnx2EExJvExiNme6g9iAT');

const {
data: { blockhash },
} = await fetchNonce(rpc, nonceAccountAddress);
const nonce = blockhash as string as Nonce;

const durableNonceTransactionMessage = setTransactionMessageLifetimeUsingDurableNonce(
{ nonce, nonceAccountAddress, nonceAuthorityAddress },
transactionMessage,
);
`

#### 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.

`ts
import { assertIsBlockhash } from '@solana/transaction-messages';

// 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 { value: blockhashIsValid } = await rpc.isBlockhashValid(blockhash).send();
} catch (e) {
// blockhash turned out not to be a base58-encoded blockhash
}
}
`

#### assertIsTransactionMessageWithDurableNonceLifetime()

From time to time you might acquire a transaction message 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 assertIsTransactionMessageWithDurableNonceLifetime function.

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

Adding instructions to a transaction message

$3

#### Instruction

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.

#### InstructionWithAccounts

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 AccountMeta | AccountLookupMeta in the order the instruction requires.

#### InstructionWithData

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.

$3

#### appendTransactionMessageInstruction()

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

`ts
import { address } from '@solana/addresses';
import { getUtf8Encoder } from '@solana/codecs-strings';
import { appendTransactionMessageInstruction } from '@solana/transaction-messages';

const memoTransactionMessage = appendTransactionMessageInstruction(
{
data: getUtf8Encoder().encode('Hello world!'),
programAddress: address('MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr'),
},
transactionMessage,
);
`

If you'd like to add multiple instructions to a transaction message at once, you may use the appendTransactionInstructions function instead which accepts an array of instructions.

#### prependTransactionMessageInstruction()

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

If you'd like to prepend multiple instructions to a transaction message at once, you may use the prependTransactionMessageInstructions function instead which accepts an array of instructions.

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

Compress transaction message using lookup tables

$3

#### AddressesByLookupTableAddress

This type represents a mapping of lookup table addresses to the addresses of the accounts that are stored in them.

$3

#### compressTransactionMessageUsingAddressLookupTables

Given a transaction message and a mapping of lookup tables to the addresses stored in them, this function will return a new transaction message with the same instructions but with all non-signer accounts that are found in the given lookup tables represented by an AccountLookupMeta instead of an AccountMeta.

This means that these accounts will take up less space in the compiled transaction message. This size reduction is most significant when the transaction includes many accounts from the same lookup table.

`ts
import { address } from '@solana/addresses';
import {
AddressesByLookupTableAddress,
compressTransactionMessageUsingAddressLookupTables,
} from '@solana/transaction-messages';
import { fetchAddressLookupTable } from '@solana-program/address-lookup-table';

const lookupTableAddress = address('4QwSwNriKPrz8DLW4ju5uxC2TN5cksJx6tPUPj7DGLAW');
const {
data: { addresses },
} = await fetchAddressLookupTable(rpc, lookupTableAddress);
const addressesByAddressLookupTable: AddressesByLookupTableAddress = {
[lookupTableAddress]: addresses,
};

const compressedTransactionMessage = compressTransactionMessageUsingAddressLookupTables(
transactionMessage,
addressesByAddressLookupTable,
);
``