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Function Signature

signTransaction(params: {
  walletMetadata: WalletMetadata;
  transaction: VersionedTransaction | Transaction | string;
  password?: string;
  externalServerKeyShares?: ServerKeyShare[];
  sponsor?: boolean;
}): Promise<string>

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Description

Signs an SVM transaction using the wallet identified by the supplied walletMetadata. The SDK is stateless — every call requires walletMetadata. Accepts a Transaction, VersionedTransaction, or hex string. Optionally requests gas sponsorship from Dynamic before signing.
When you pass externalServerKeyShares (the caller-supplied path), walletMetadata.externalServerKeySharesBackupInfo must also be present — signTransaction throws if shares are supplied but backup metadata is missing. The full walletMetadata returned from createWalletAccount / importPrivateKey already includes it; identity-only metadata from fetchWalletMetadata will be rejected.

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Parameters

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Required Parameters

  • walletMetadata (WalletMetadata) - Non-sensitive wallet metadata persisted from createWalletAccount() / importPrivateKey(). The signer address comes from walletMetadata.accountAddress.
  • transaction (VersionedTransaction | Transaction | string) - The transaction to sign

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Optional Parameters

  • password (string) - Required if the wallet was created with backUpToDynamic: true.
  • externalServerKeyShares (ServerKeyShare[]) - Caller-supplied plaintext shares.
  • sponsor (boolean) - If true, requests gas sponsorship from Dynamic before signing. Requires a Transaction or VersionedTransaction (not a hex string).

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Returns

  • Promise<string> - A base58-encoded Ed25519 signature — exactly 88 characters, which decodes to 64 bytes.
This is the raw signature only, not the full signed transaction.Verified return format:
typeof: string
length: 88 characters
decoded bytes: 64  (Ed25519 signature)
example: "5pkf7k6nDCtoohetqdWoMCJS9Vd..."
Calling VersionedTransaction.deserialize() on the decoded bytes will throw “Reached end of buffer unexpectedly” — confirming the 64 bytes are a signature, not a serialized transaction.To broadcast: decode the signature and add it back to the transaction using decodeBase58 and addSignatureToTransaction from @dynamic-labs-wallet/node-svm, then call connection.sendRawTransaction(signedTx.serialize()). See the example below.Passing the string directly to connection.sendRawTransaction() or the SDK’s sendTransaction() will fail — Buffer.from(base58string) interprets the characters as UTF-8 bytes (not the decoded signature), producing a garbled payload.

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Example

import { authenticatedSvmClient } from './client';
import { decodeBase58, addSignatureToTransaction } from '@dynamic-labs-wallet/node-svm';
import {
  Connection, Transaction, SystemProgram, LAMPORTS_PER_SOL, PublicKey,
} from '@solana/web3.js';

const svmClient = await authenticatedSvmClient();

const walletMetadata = JSON.parse(await redis.get(`wallet:${accountAddress}`));
const externalServerKeyShares = await vault.read(`wallet:${accountAddress}/shares`);

const connection = new Connection(
  process.env.SOLANA_RPC_URL ?? 'https://api.mainnet-beta.solana.com',
  'confirmed'
);
const { blockhash } = await connection.getLatestBlockhash();

const transaction = new Transaction().add(
  SystemProgram.transfer({
    fromPubkey: new PublicKey(walletMetadata.accountAddress),
    toPubkey: new PublicKey('11111111111111111111111111111112'),
    lamports: LAMPORTS_PER_SOL * 0.001,
  })
);
transaction.recentBlockhash = blockhash;
transaction.feePayer = new PublicKey(walletMetadata.accountAddress);

// Returns base58 signature (64 bytes), NOT the full signed transaction
const signatureBase58 = await svmClient.signTransaction({
  walletMetadata,
  externalServerKeyShares,
  transaction,
  password: 'user-password',
});

// Decode and attach the signature before broadcasting
const signatureBytes = decodeBase58(signatureBase58);
const signedTx = addSignatureToTransaction({
  transaction,
  signature: signatureBytes,
  signerPublicKey: new PublicKey(walletMetadata.accountAddress),
});

const txid = await connection.sendRawTransaction(signedTx.serialize());
await connection.confirmTransaction(txid, 'confirmed');
console.log('Transaction confirmed:', txid);

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With Gas Sponsorship

Pass sponsor: true to have Dynamic sponsor the transaction fees. Gas sponsorship must be enabled in the Dynamic dashboard. 
import { authenticatedSvmClient } from './client';
import { decodeBase58, addSignatureToTransaction } from '@dynamic-labs-wallet/node-svm';
import {
  Connection, Transaction, SystemProgram, LAMPORTS_PER_SOL, PublicKey,
} from '@solana/web3.js';

const svmClient = await authenticatedSvmClient();

const walletMetadata = JSON.parse(await redis.get(`wallet:${accountAddress}`));
const externalServerKeyShares = await vault.read(`wallet:${accountAddress}/shares`);

const connection = new Connection(
  process.env.SOLANA_RPC_URL ?? 'https://api.mainnet-beta.solana.com',
  'confirmed'
);
const { blockhash } = await connection.getLatestBlockhash();

const transaction = new Transaction().add(
  SystemProgram.transfer({
    fromPubkey: new PublicKey(walletMetadata.accountAddress),
    toPubkey: new PublicKey('11111111111111111111111111111112'),
    lamports: LAMPORTS_PER_SOL * 0.001,
  })
);
transaction.recentBlockhash = blockhash;
transaction.feePayer = new PublicKey(walletMetadata.accountAddress);

// sponsor: true replaces the fee payer with the Dynamic sponsor
const signatureBase58 = await svmClient.signTransaction({
  walletMetadata,
  externalServerKeyShares,
  transaction,
  password: 'user-password',
  sponsor: true,
});

const signatureBytes = decodeBase58(signatureBase58);
const signedTx = addSignatureToTransaction({
  transaction,
  signature: signatureBytes,
  signerPublicKey: new PublicKey(walletMetadata.accountAddress),
});

const txid = await connection.sendRawTransaction(signedTx.serialize());
await connection.confirmTransaction(txid, 'confirmed');
console.log('Sponsored transaction confirmed:', txid);
Last modified on June 23, 2026