Key Gateway

import { ViemWalletEip712Signer } from '@farcaster/hub-web';
import { walletClient, account } from './clients.ts';
import { getPublicKey } from './signer.ts';
import { readNonce, getDeadline } from './helpers.ts';

const publicKey = await getPublicKey();
const metadata = await getMetadata();
const nonce = await readNonce();
const deadline = getDeadline();

const eip712Signer = new ViemWalletEip712Signer(walletClient);
const signature = await eip712signer.signAdd({
  owner: account,
  keyType: 1,
  key: publicKey,
  metadataType: 1,
  metadata,
  nonce,
  deadline,
});

import { KEY_GATEWAY_EIP_712_TYPES } from '@farcaster/hub-web';
import { bytesToHex } from 'viem';
import { walletClient, account } from './clients.ts';
import { getPublicKey } from './signer.ts';
import { getMetadata } from './metadata.ts';
import { readNonce, getDeadline } from './helpers.ts';

const publicKey = await getPublicKey();
const metadata = await getMetadata();
const nonce = await readNonce();
const deadline = getDeadline();

const signature = await walletClient.signTypedData({
  account,
  ...KEY_GATEWAY_EIP_712_TYPES,
  primaryType: 'Add',
  message: {
    owner: account,
    keyType: 1,
    key: bytesToHex(publicKey),
    metadataType: 1,
    metadata,
    nonce,
    deadline,
  },
});

import { KEY_GATEWAY_ADDRESS, keyGatewayABI } from '@farcaster/hub-web';
import { publicClient, account } from './clients.ts';

export const getDeadline = () => {
  const now = Math.floor(Date.now() / 1000);
  const oneHour = 60 * 60;
  return now + oneHour;
};

export const readNonce = async () => {
  return await publicClient.readContract({
    address: KEY_GATEWAY_ADDRESS,
    abi: keyGatewayABI,
    functionName: 'nonces',
    args: [account],
  });
};

import { ViemLocalEip712Signer } from '@farcaster/hub-web';
import { privateKeyToAccount } from 'viem/accounts';
import { getDeadline } from './helpers.ts';
import { getPublicKey } from './signer.ts';

// App account
export const appAccount = privateKeyToAccount('0x...');

const deadline = getDeadline();
const publicKey = await getPublicKey();

export const getMetadata = async () => {
  const eip712signer = new ViemLocalEip712Signer(appAccount);
  const metadata = await eip712signer.getSignedKeyRequestMetadata({
    requestFid: 9152n, // App fid
    key: publicKey,
    deadline,
  });
  if (metadata.isOk()) {
    return metadata.value;
  }
};

import * as ed from '@noble/ed25519';
import { NobleEd25519Signer } from '@farcaster/hub-web';

const privateKeyBytes = ed.utils.randomPrivateKey();
export const accountKey = new NobleEd25519Signer(privateKeyBytes);

export const getPublicKey = async () => {
  const accountKeyResult = await accountKey.getSignerKey();
  if (accountKeyResult.isOk()) {
    return accountKeyResult.value;
  }
};

import { createWalletClient, createPublicClient, custom, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { optimism } from 'viem/chains';

export const publicClient = createPublicClient({
  chain: optimism,
  transport: http(),
});

export const walletClient = createWalletClient({
  chain: optimism,
  transport: custom(window.ethereum),
});

// JSON-RPC Account
export const [account] = await walletClient.getAddresses();

// Local Account
export const account = privateKeyToAccount('0x...');