Custom Universal Signer

Overview

If you don't have a supported library signer or want to create a custom implementation, you can construct a Universal Signer manually.

Custom Universal Signer

PushChain.utils.signer.construct(account, {options}): Promise<UniversalSigner>

const account = {
  address: '<WALLET_ADDRESS>',
  chain: '<PushChain.CONSTANTS.CHAIN.CHAIN_TYPE'>
};

const customSignAndSendTransaction = async (unsignedTx) => {
  return new Uint8Array('<RESPONSE_TO_SIGN_AND_SEND_TRANSACTION>');
};

const customSignMessage = async (data) => {
  return new Uint8Array('<RESPONSE_TO_SIGN_MESSAGE>');
};

const customSignTypedData = async (typedDataArgs) => {
  return new Uint8Array('<RESPONSE_TO_SIGN_TYPED_DATA>');
};

const skeleton = PushChain.utils.signer.construct(account, {
  signAndSendTransaction: customSignAndSendTransaction,
  signMessage: customSignMessage,
  signTypedData: customSignTypedData
});

const universalSigner = await PushChain.utils.signer.toUniversal(skeleton);

TheseArgumentsare mandatory

Arguments	Type	Description
account	UniversalAccount	Account information containing address and chain
options	Object	Object containing the signing function implementations
options.signAndSendTransaction	(unsignedTx: Uint8Array) => Promise<Uint8Array>	Function to sign transaction data
options.signMessage	(data: Uint8Array) => Promise<Uint8Array>	Function to sign raw message data
options.signTypedData	(params) => Promise<Uint8Array>	Function to sign typed data (EIP-712)
options.signAuthorization	(params: SignAuthorizationParams) => Promise<SignedAuthorization>	Optional. Function to sign an EIP-7702 authorization delegating the EOA's code to a contract

Optional `signAuthorization` for EIP-7702 atomic batching

Provide signAuthorization when your wallet can sign raw EIP-7702 authorizations. With it, multicall batches sent from a native Push Chain EOA execute atomically in a single EIP-7702 (type-4) transaction, which means that all calls succeed or the whole transaction reverts. Without it, the SDK safely falls back to the sequential per-call execution (the transaction response's atomic field tells you which path ran).

The SDK wires this automatically for ethers v6 Wallet (local key) and viem local accounts (e.g. privateKeyToAccount). JSON-RPC accounts like browser wallets like MetaMask cannot sign raw EIP-7702 authorizations, and neither can ethers v5 signers.

// SignAuthorizationParams
{
  contractAddress: `0x${string}`; // contract to delegate the EOA's code to
  chainId?: number;               // defaults to the signer's chain
  nonce?: number;                 // omit to let the wallet fill it
  executor?: 'self';              // set when the signing EOA also submits the tx
}

// SignedAuthorization (viem-compatible)
{
  address: `0x${string}`;
  chainId: number;
  nonce: number;
  r: `0x${string}`;
  s: `0x${string}`;
  yParity: number;
  v?: bigint;
}

Returns `UniversalSignerSkeleton` <object>

// UniversalSignerSkeleton object
{
  signerId: 'CustomGeneratedSigner',
  account: {
    chain: 'eip155:42101',
    address: '0x98cA97d2FB78B3C0597E2F78cd11868cACF423C5'
  },
  signMessage: [AsyncFunction: customSignMessage],
  signAndSendTransaction: [AsyncFunction: customSignAndSendTransaction],
  signTypedData: [AsyncFunction: customSignTypedData]
}

Live Playground: Creating Custom Universal Signer from Ethers.js 👇.

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Next Steps

• Initialize Push Chain Client with the Universal Signer
• Abstract away creation of the Universal Signer using UI Kit