If you’re not using React, use the @account-kit/signer package to create smart wallets on Solana, sign messages, sign transactions, and sponsor transaction fees.

If you’re using React, get started with Solana wallets here.

Create a Solana signer

Once you’ve authenticated users, convert the AlchemyWebSigner to a Solana compatible signer using either of these methods:

import { 
import signer
signer } from "./signer";
import { 
class SolanaSigner
The SolanaSigner class is used to sign transactions and messages for the Solana blockchain. It provides methods to add signatures to transactions and sign messages.
SolanaSigner } from "@account-kit/signer";

const 
const solanaSigner: any
solanaSigner = 
import signer
signer.
any
toSolanaSigner();
// OR
const 
const solanaSigner2: SolanaSigner
solanaSigner2 = new 
new SolanaSigner(client: BaseSignerClient): SolanaSigner
Constructor for the SolanaSigner class which is a wrapper around the alchemy client, and is more focused on the solana web3
SolanaSigner(
import signer
signer);

import { 
class AlchemyWebSigner
A SmartAccountSigner that can be used with any SmartContractAccount
AlchemyWebSigner } from "@account-kit/signer";

export const 
const signer: AlchemyWebSigner
signer = new 
new AlchemyWebSigner(params: AlchemySignerParams): AlchemyWebSigner
Initializes an instance with the provided Alchemy signer parameters after parsing them with a schema.
AlchemyWebSigner({
  
client: ({
    connection: {
        apiKey: string;
        rpcUrl?: undefined;
        jwt?: undefined;
    } | {
        jwt: string;
        rpcUrl?: undefined;
        apiKey?: undefined;
    } | {
        rpcUrl: string;
        apiKey?: undefined;
        jwt?: undefined;
    } | {
        rpcUrl: string;
        jwt: string;
        apiKey?: undefined;
    };
    ... 4 more ...;
    enablePopupOauth?: boolean | undefined;
} | AlchemySignerWebClient) & (AlchemySignerWebClient | ... 1 more ... | undefined)
client: {
    
connection: {
    apiKey: string;
}
connection: {
      
apiKey: string
apiKey: "API_KEY",
    },
    
iframeConfig: {
    iframeContainerId: string;
}
iframeConfig: {
      
iframeContainerId: string
iframeContainerId: "alchemy-signer-iframe-container",
    },
  },
});

Sign Message

To sign either a string or byte array with your Solana wallet use the signMessage method. The method accepts a UInt8Array as input:

import { 
import signer
signer } from "./signer";
import { 
function toBytes(value: string | bigint | number | boolean | Hex, opts?: ToBytesParameters): ByteArray
Encodes a UTF-8 string, hex value, bigint, number or boolean to a byte array.
Docs: https://viem.sh/docs/utilities/toBytes
Example: https://viem.sh/docs/utilities/toBytes#usage
toBytes } from "viem";

const 
const solanaSigner: any
solanaSigner = 
import signer
signer.
any
toSolanaSigner();
const 
const signedMessage: any
signedMessage = await 
const solanaSigner: any
solanaSigner.
any
signMessage(
  
function toBytes(value: string | bigint | number | boolean | Hex, opts?: ToBytesParameters): ByteArray
Encodes a UTF-8 string, hex value, bigint, number or boolean to a byte array.
Docs: https://viem.sh/docs/utilities/toBytes
Example: https://viem.sh/docs/utilities/toBytes#usage
toBytes("Message as a string converted into UInt8Array"),
);

import { 
class AlchemyWebSigner
A SmartAccountSigner that can be used with any SmartContractAccount
AlchemyWebSigner } from "@account-kit/signer";

export const 
const signer: AlchemyWebSigner
signer = new 
new AlchemyWebSigner(params: AlchemySignerParams): AlchemyWebSigner
Initializes an instance with the provided Alchemy signer parameters after parsing them with a schema.
AlchemyWebSigner({
  
client: ({
    connection: {
        apiKey: string;
        rpcUrl?: undefined;
        jwt?: undefined;
    } | {
        jwt: string;
        rpcUrl?: undefined;
        apiKey?: undefined;
    } | {
        rpcUrl: string;
        apiKey?: undefined;
        jwt?: undefined;
    } | {
        rpcUrl: string;
        jwt: string;
        apiKey?: undefined;
    };
    ... 4 more ...;
    enablePopupOauth?: boolean | undefined;
} | AlchemySignerWebClient) & (AlchemySignerWebClient | ... 1 more ... | undefined)
client: {
    
connection: {
    apiKey: string;
}
connection: {
      
apiKey: string
apiKey: "API_KEY",
    },
    
iframeConfig: {
    iframeContainerId: string;
}
iframeConfig: {
      
iframeContainerId: string
iframeContainerId: "alchemy-signer-iframe-container",
    },
  },
});

Sign Transaction

To sign a prepared transaction with your Solana wallet use the addSignature method. The following example demonstrates signing a transfer transaction:

1
import { Connection, PublicKey, SystemProgram } from "@solana/web3.js";
2
3
async function signTransaction(
4
  signer: SolanaSigner,
5
  toAddress: string,
6
  value: number,
7
) {
8
  const instructions = [
9
    SystemProgram.transfer({
10
      fromPubkey: new PublicKey(signer.address),
11
      toPubkey: new PublicKey(params.transfer.toAddress),
12
      lamports: params.transfer.amount,
13
    }),
14
  ];
15
16
  // Construct transaction with the provided instructions
17
  const transaction = await signer.createTransfer(instructions, connection);
18
19
  // Sign the transaction using the Solana wallet
20
  await signer.addSignature(transaction);
21
22
  return transaction;
23
}
24
25
const signedTransaction = await signTransaction(signer, "<ToAddress>", 1234);
26
// Broadcast the signed transaction to the network using @solana/web3.js
27
const connection = new Connection(
28
  "https://solana-devnet.g.alchemy.com/v2/<API_KEY>",
29
);
30
await connection.sendTransaction(signedTransaction);

Sponsor transaction fees

To sponsor transaction fees on Solana:

1. Set up your sponsorship policy in the dashboard to retrieve a policy ID
2. Add sponsorship to the preparred transaction before signing and sending

1
import { Connection, PublicKey, SystemProgram } from "@solana/web3.js";
2
3
async function signTransaction(
4
  signer: SolanaSigner,
5
  toAddress: string,
6
  value: number,
7
) {
8
  const instructions = [
9
    SystemProgram.transfer({
10
      fromPubkey: new PublicKey(signer.address),
11
      toPubkey: new PublicKey(params.transfer.toAddress),
12
      lamports: params.transfer.amount,
13
    }),
14
  ];
15
16
  // First - add sponsorship to the preparred transaction
17
  const transaction = await signer.addSponsorship(
18
    instructions,
19
    connection,
20
    "<policyId>", // Replace with your solana sponsorship policy ID: https://dashboard.alchemy.com/services/gas-manager/configuration
21
  );
22
23
  // Sign the transaction using the Solana wallet
24
  await signer.addSignature(transaction);
25
26
  return transaction;
27
}
28
29
const signedTransaction = await signTransaction(signer, "<ToAddress>", 1234);
30
31
// Broadcast the signed transaction to the network using @solana/web3.js
32
const connection = new Connection(
33
  "https://solana-devnet.g.alchemy.com/v2/<API_KEY>", // Replace with your Alchemy API key
34
);
35
36
await connection.sendTransaction(signedTransaction);