useNeroWallet

The useNeroWallet React hook provides wallet generation and signing capabilities to components wrapped by NeroMpcAuthProvider.

Usage

import { useNeroWallet } from "@nerochain/mpc-sdk/react";

function WalletView() {
  const {
    wallet,
    hasWallet,
    generateWallet,
    signMessage,
    signTypedData,
    isGenerating,
    isSigning,
    error,
  } = useNeroWallet();

  if (!hasWallet) {
    return (
      <button onClick={generateWallet} disabled={isGenerating}>
        {isGenerating ? "Generating..." : "Generate Wallet"}
      </button>
    );
  }

  return (
    <div>
      <p>EOA: {wallet?.eoaAddress}</p>
      <button
        onClick={() => signMessage("Hello, NERO!")}
        disabled={isSigning}
      >
        Sign Message
      </button>
      {error && <p>{error.message}</p>}
    </div>
  );
}

Return Value

Field	Type	Description
`wallet`	`WalletInfo \| null`	Current wallet information; `null` if not generated
`hasWallet`	`boolean`	Indicates existing key share for current user
`generateWallet`	`() => Promise<WalletInfo>`	Triggers MPC key generation protocol
`signMessage`	`(message: string) => Promise<string>`	Signs Ethereum personal messages (EIP-191)
`signTypedData`	`(domain, types, primaryType, value) => Promise<string>`	Signs EIP-712 typed data
`isGenerating`	`boolean`	Loading state during wallet generation
`isSigning`	`boolean`	Loading state during signing operations
`error`	`Error \| null`	Last operation error; reset at operation start

State Management

Derived state (from context):

wallet and hasWallet derive from the shared SDK state, not local state
Updated automatically when the SDK emits authentication or connection events

Local state:

isGenerating, isSigning, and error are managed via useState

generateWallet()

Initiates MPC key generation. Throws synchronously if the SDK is uninitialized. Sets isGenerating to true, resets error to null, and always clears the loading flag in the finally block.

const { generateWallet, isGenerating, error } = useNeroWallet();

try {
  const walletInfo = await generateWallet();
  console.log("Address:", walletInfo.eoaAddress);
} catch (err) {
  console.error("Generation failed:", err);
}

Signs arbitrary strings using the Ethereum personal signing prefix. Requires both the SDK and an existing wallet. Throws "Wallet not available" if preconditions are unmet, without entering the loading state.

const { signMessage, isSigning } = useNeroWallet();

const signature = await signMessage("Hello, NERO!");
console.log("Signature:", signature);

signTypedData(domain, types, primaryType, value)

Signs EIP-712 typed data. Accepts a domain struct, type definitions map, primary type name, and message data. Returns a hex signature string.

const { signTypedData, isSigning } = useNeroWallet();

const signature = await signTypedData(
  { name: "MyApp", version: "1", chainId: 689 },
  { Transfer: [{ name: "to", type: "address" }, { name: "amount", type: "uint256" }] },
  "Transfer",
  { to: "0x1234...", amount: "1000000000000000000" }
);

Error Handling Pattern

All operations follow consistent error semantics:

Reset error to null at operation start
On rejection, set error and re-throw for caller handling
Always reset loading flags in finally blocks

Memoization

The three operation callbacks use useCallback:

generateWallet depends on [sdk]
signMessage and signTypedData depend on [sdk, state.hasWallet]

This ensures stable references across renders.

Context Requirement

The hook requires a parent NeroMpcAuthProvider. If used outside this provider, it throws:

useNeroMpcAuthContext must be used within a NeroMpcAuthProvider

useNeroWallet

useNeroWallet

Usage

Return Value

State Management

generateWallet()

signMessage(message)

signTypedData(domain, types, primaryType, value)

Error Handling Pattern

Memoization

Context Requirement

On this page