Add Memo to Transaction

Learn how to add a memo to a Solana transaction to include additional information or comments.

Code Example

#!/usr/bin/env python3
"""
Solana Cookbook - How to Add a Memo to a Transaction
"""

import asyncio
from solana.rpc.async_api import AsyncClient
from solders.keypair import Keypair
from solders.system_program import transfer, TransferParams
from solders.transaction import VersionedTransaction
from solders.message import MessageV0
from spl.memo.instructions import create_memo, MemoParams
from solders.pubkey import Pubkey

async def main():
    rpc = AsyncClient("https://api.devnet.solana.com")

    sender = Keypair()
    recipient = Keypair()

    amount = 1_000_000_000  # 1 SOL
    memo_text = "Hello, Solana! This is a memo."

    async with rpc:
        # Get latest blockhash
        latest_blockhash = await rpc.get_latest_blockhash()

        # Create transfer instruction
        transfer_instruction = transfer(
            TransferParams(
                from_pubkey=sender.pubkey(),
                to_pubkey=recipient.pubkey(),
                lamports=amount
            )
        )

        # Create memo instruction
        memo_instruction = create_memo(
            MemoParams(
                program_id=Pubkey.from_string("MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr"),
                signer=sender.pubkey(),
                message=memo_text.encode('utf-8')
            )
        )

        # Create message with both instructions
        message = MessageV0.try_compile(
            payer=sender.pubkey(),
            instructions=[transfer_instruction, memo_instruction],
            address_lookup_table_accounts=[],
            recent_blockhash=latest_blockhash.value.blockhash
        )

        # Create transaction
        transaction = VersionedTransaction(message, [sender])

        print(f"Sender: {sender.pubkey()}")
        print(f"Recipient: {recipient.pubkey()}")
        print(f"Transfer Amount: {amount / 1_000_000_000} SOL")
        print(f"Memo: {memo_text}")
        print(f"Transaction with memo created successfully")

if __name__ == "__main__":
    asyncio.run(main())

Explanation

This example demonstrates how to add a memo to a Solana transaction:

1. Create Standard Transaction: Build a regular transfer transaction
2. Create Memo Instruction: Use the SPL Memo program to create a memo instruction
3. Combine Instructions: Include both transfer and memo instructions in the same transaction
4. Encode Message: Convert the memo text to bytes for the instruction
5. Create Transaction: Build a versioned transaction with both instructions

Key Concepts

• SPL Memo Program: Official program for adding text memos to transactions
• Multiple Instructions: A single transaction can contain multiple instructions
• Memo Program ID: The fixed program ID for the memo program
• UTF-8 Encoding: Memo text must be encoded as bytes
• Transaction Ordering: Instructions are executed in the order they appear

Usage

To run this example:

1. Install required dependencies:

   pip install solana-py solders spl-token
   

2. Run the script:

   python add_memo_to_transaction.py
   

Use Cases

Memos are useful for: - Adding payment references or invoice numbers - Including transaction descriptions - Storing metadata on-chain - Creating audit trails - Adding context to transfers

Note: Memos are publicly visible on the blockchain and increase transaction size and fees slightly.