Signing Transactions & Messages

Sign transaction messages and off-chain auth payloads with connected wallets.

Recipe

import { signTransactionMessageWithSigners } from "@solana/kit";
// wallet adapter provides TransactionSendingSigner compatible adapter

When to reach for this:

• Any user-paid transaction in the browser.
• NFT mints, swaps, and game actions.
• Sign-in with Solana messages.

Working Example

"use client";
import { useWallet } from "@solana/wallet-adapter-react";
import {
  createTransactionMessage,
  setTransactionMessageFeePayerSigner,
  setTransactionMessageLifetimeUsingBlockhash,
  appendTransactionMessageInstruction,
  signTransactionMessageWithSigners,
  createSolanaRpc,
} from "@solana/kit";
import { getTransferSolInstruction } from "@solana-program/system";
 
export function useSendSol() {
  const { publicKey, signTransaction } = useWallet();
  const rpc = createSolanaRpc(process.env.NEXT_PUBLIC_RPC_URL!);
 
  return async function send(recipient: string, lamports: bigint) {
    if (!publicKey || !signTransaction) throw new Error("Wallet not connected");
    const { value: bh } = await rpc.getLatestBlockhash().send();
    // Wire wallet signer helper from your adapter bridge
    let msg = createTransactionMessage({ version: 0 });
    // ... append transfer ix, sign with wallet, send via rpc
  };
}

What this demonstrates:

• Build message with kit; wallet provides signing capability.
• Fee payer must match connected pubkey.
• Simulate before wallet modal when possible.

Deep Dive

How It Works

• Wallets never expose secret keys - they sign inside the extension.
• Partial signing supported for multisig flows.
• signMessage returns ed25519 signature over arbitrary bytes.
• TransactionSendingSigner bridges adapter to kit pipeline.

Gotchas

• Fee payer mismatch - wallet rejects. Fix: use connected address as payer.
• Oversized transactions - wallet UI fails. Fix: ALTs and fewer accounts.
• Blind signing on hardware - security risk. Fix: verified transaction preview.
• Assuming signTransaction returns confirmed tx - only signs; you still send.
• Reusing blockhash after long UX - expiry. Fix: rebuild message.

Alternatives

FAQs

Related

• Client-Side Signing - Next.js patterns
• Signing & Sending - kit send pipeline
• Keypairs & Signers - signer model

Stack versions: This page was written for Agave 4.1.1, Solana CLI 3.0.10, Anchor 0.32.1, anchor-lang 0.32.1, Rust 1.91.1, @solana/kit 7.0.0, Surfpool 0.12.0, and LiteSVM 0.6.x.