Viem

This is your go-to for writing TypeScript that talks to Ethereum and other EVM chains outside of React apps. Think Node scripts, CLI tools, or backend services that need to read contracts, send transactions, or watch events. The skill hammers home the critical patterns like using `as const` on ABIs for type safety, always simulating contracts before writes, and handling BigInt correctly for token amounts. It's built around viem 2.x, which is genuinely cleaner than the old ethers.js patterns. If you're building a wagmi/React app, skip this and use the wagmi skill instead. This is strictly for non-hook blockchain code.

skills.sh installs: 186
last updated: Aug 21, 2026

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Install

$ npx -y skills add 0xsardius/onchain-typescript-skills --skill viem --agent claude-code

Installs into .claude/skills of the current project.

Files

Viem Skill

Version: Viem 2.x | Official Docs

Viem is the modern TypeScript interface for Ethereum. This skill ensures correct patterns for contract interactions, client setup, and type safety.

Quick Reference

import { createPublicClient, createWalletClient, http } from 'viem'
import { mainnet } from 'viem/chains'
import { privateKeyToAccount } from 'viem/accounts'

Critical Patterns

1. Client Setup

Public Client (read-only operations):

const publicClient = createPublicClient({
  chain: mainnet,
  transport: http('https://eth-mainnet.g.alchemy.com/v2/YOUR_KEY'),
})

Wallet Client (write operations):

const account = privateKeyToAccount('0x...')
const walletClient = createWalletClient({
  account,
  chain: mainnet,
  transport: http('https://eth-mainnet.g.alchemy.com/v2/YOUR_KEY'),
})