viem を使った mint

viem または ethers.js を用いた TypeScript、Remix でデプロイした ERC-721 contract、IPFS ホスティング用の Pinata を使って、Chiliz Chain 上でプログラムから NFT を mint します。

minting プロセスをきめ細かく制御したい開発者は、EVM ベースのプロジェクト向けの TypeScript インターフェースである viem を使い、素の TypeScript で実装できます。Ethers.js ライブラリ も堅牢なアプローチです。

vanilla で進める場合、thirdweb のようなフレームワークに頼るときよりも少し多くの作業が必要になります。たとえば、自前で IPFS node を運用しない限り、有料の NFT ストレージプラットフォームに頼る必要があります。

この例では IPFS host として Pinata を使用します。 また、OpenZeppelin ERC-721 contract を Chiliz Chain 上に自分で deploy する必要があります。Remix IDE を使えば、ブラウザ内の IDE でこれを行えます。block explorer を使って contract を verify するのを忘れずに!

それでは、viem、Pinata SDK、そして dotenv モジュールをインストールしましょう:

npm i viem pinata dotenv

ニーズに合わせて .env ファイルを設定します:

# Wallet / contract
PRIVATE_KEY=0xabc...                      # server-side only
CONTRACT_ADDRESS=0xYourErc721Address
RECIPIENT=0xRecipientOrLeaveEmpty         # optional; defaults to minter

# Pinata
PINATA_JWT=eyJhbGciOi...                  # JWT from Pinata dashboard
PINATA_GATEWAY=your-subdomain.mypinata.cloud

# Single mint
IMAGE_PATH=./art/image.png
NAME=My Chiliz NFT
DESCRIPTION=Minted on Chiliz with viem

# Batch mint
IMAGES_DIR=./art
NAME_PREFIX=My Chiliz NFT
BATCH_DESCRIPTION=Batch minted on Chiliz with viem

それでは、コードを見ていきましょう。 そのまま使うのではなく、参考にしてください!

単一の NFT を mint する

import 'dotenv/config';
import fs from 'fs';
import path from 'path';

import { createWalletClient, createPublicClient, http, parseEventLogs } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import type { Address } from 'viem';
import { chiliz, spicy } from 'viem/chains';
import { PinataSDK } from 'pinata';

// Minimal ABI: safeMint(to, uri) + tokenURI + Transfer
const abi = [
  { type: 'function', name: 'safeMint', stateMutability: 'nonpayable',
    inputs: [{ name: 'to', type: 'address' }, { name: 'uri', type: 'string' }], outputs: [] },
  { type: 'function', name: 'tokenURI', stateMutability: 'view',
    inputs: [{ name: 'tokenId', type: 'uint256' }], outputs: [{ type: 'string' }] },
  { type: 'event', name: 'Transfer',
    inputs: [
      { name: 'from', type: 'address', indexed: true },
      { name: 'to', type: 'address', indexed: true },
      { name: 'tokenId', type: 'uint256', indexed: true },
    ]},
] as const;

function guessMime(p: string) {
  const ext = path.extname(p).toLowerCase();
  if (ext === '.png') return 'image/png';
  if (ext === '.jpg' || ext === '.jpeg') return 'image/jpeg';
  if (ext === '.webp') return 'image/webp';
  if (ext === '.gif') return 'image/gif';
  if (ext === '.mp4') return 'video/mp4';
  if (ext === '.webm') return 'video/webm';
  return 'application/octet-stream';
}

async function main() {
  // Choose your network: use `spicy` for Spicy Testnet, switch to `chiliz` for Chiliz Chain Mainnet.
  const chain = spicy; // Change to `chiliz` for Mainnet

  const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`);
  const walletClient = createWalletClient({ account, chain, transport: http() });
  const publicClient = createPublicClient({ chain, transport: http() });

  const address = process.env.CONTRACT_ADDRESS as Address;
  const recipient = (process.env.RECIPIENT as Address) || account.address;

  // IPFS upload (Pinata)
  const pinata = new PinataSDK({
    pinataJwt: process.env.PINATA_JWT!,
    pinataGateway: process.env.PINATA_GATEWAY!,
  });

  const filePath = process.env.IMAGE_PATH!;
  const fileBlob = new Blob([fs.readFileSync(filePath)], { type: guessMime(filePath) });
  const fileObj = new File([fileBlob], path.basename(filePath), { type: guessMime(filePath) });

  const up = await pinata.upload.public.file(fileObj);
  const imageUri = `ipfs://${up.cid}`;

  const meta = await pinata.upload.public.json({
    name: process.env.NAME!,
    description: process.env.DESCRIPTION!,
    image: imageUri,
  });
  const metadataUri = `ipfs://${meta.cid}`;

  // Mint on-chain via viem
  const txHash = await walletClient.writeContract({
    address,
    abi,
    functionName: 'safeMint',
    args: [recipient, metadataUri],
  });

  const receipt = await publicClient.waitForTransactionReceipt({ hash: txHash });

  const ZERO = '0x0000000000000000000000000000000000000000';
  const logs = parseEventLogs({ abi, logs: receipt.logs, eventName: 'Transfer' });
  const mintLog = logs.find(l => (l.args as any).from?.toLowerCase?.() === ZERO);
  const tokenId = mintLog ? (mintLog.args as any).tokenId : undefined;

  console.log('tx:', txHash, '| tokenId:', tokenId ?? '(not parsed)', '| tokenURI:', metadataUri);
}

main().catch(err => (console.error(err), process.exit(1)));

NFT のコレクションを mint する

import 'dotenv/config';
import fs from 'fs';
import path from 'path';
// import { Blob } from 'buffer'; // Node 18: uncomment the next line to get Blob.

import { createWalletClient, createPublicClient, http, parseEventLogs } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import type { Address } from 'viem';
import { chiliz, spicy } from 'viem/chains';
import { PinataSDK } from 'pinata';

// Minimal ABI: safeMint(to, uri) + tokenURI + Transfer
const abi = [
  { type: 'function', name: 'safeMint', stateMutability: 'nonpayable',
    inputs: [{ name: 'to', type: 'address' }, { name: 'uri', type: 'string' }], outputs: [] },
  { type: 'function', name: 'tokenURI', stateMutability: 'view',
    inputs: [{ name: 'tokenId', type: 'uint256' }], outputs: [{ type: 'string' }] },
  { type: 'event', name: 'Transfer',
    inputs: [
      { name: 'from', type: 'address', indexed: true },
      { name: 'to', type: 'address', indexed: true },
      { name: 'tokenId', type: 'uint256', indexed: true },
    ]},
] as const;

function guessMime(p: string) {
  const ext = path.extname(p).toLowerCase();
  if (ext === '.png') return 'image/png';
  if (ext === '.jpg' || ext === '.jpeg') return 'image/jpeg';
  if (ext === '.webp') return 'image/webp';
  if (ext === '.gif') return 'image/gif';
  if (ext === '.mp4') return 'video/mp4';
  if (ext === '.webm') return 'video/webm';
  return 'application/octet-stream';
}

async function main() {
  // Choose your network: use `spicy` for Spicy Testnet, switch to `chiliz` for Mainnet.
  const chain = spicy; // Change to `chiliz` for Mainnet

  const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`);
  const walletClient = createWalletClient({ account, chain, transport: http() });
  const publicClient = createPublicClient({ chain, transport: http() });

  const address = process.env.CONTRACT_ADDRESS as Address;
  const recipient = (process.env.RECIPIENT as Address) || account.address;

  // IPFS upload (Pinata)
  const pinata = new PinataSDK({
    pinataJwt: process.env.PINATA_JWT!,
    pinataGateway: process.env.PINATA_GATEWAY!, // optional; not needed for ipfs:// URIs
  });

  const filePath = process.env.IMAGE_PATH!;
  const fileBlob = new Blob([fs.readFileSync(filePath)], { type: guessMime(filePath) });

  // Pass a Blob directly
  const up = await pinata.upload.public.file(fileBlob);
  const imageUri = `ipfs://${up.cid}`;

  const meta = await pinata.upload.public.json({
    name: process.env.NAME!,
    description: process.env.DESCRIPTION!,
    image: imageUri,
  });
  const metadataUri = `ipfs://${meta.cid}`;

  // Mint on-chain via viem
  const txHash = await walletClient.writeContract({
    address,
    abi,
    functionName: 'safeMint',
    args: [recipient, metadataUri],
  });

  const receipt = await publicClient.waitForTransactionReceipt({ hash: txHash });

  const ZERO = '0x0000000000000000000000000000000000000000';
  const logs = parseEventLogs({ abi, logs: receipt.logs, eventName: 'Transfer' });
  const mintLog = logs.find(l => (l.args as any).from?.toLowerCase?.() === ZERO);
  const tokenId = mintLog ? (mintLog.args as any).tokenId : undefined;

  console.log('tx:', txHash, '| tokenId:', tokenId ?? '(not parsed)', '| tokenURI:', metadataUri);
}

main().catch(err => (console.error(err), process.exit(1)));