Web3 Docs

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name: web3-docs description: | Up-to-date documentation and code patterns for Solidity, Foundry, Hardhat, Viem, Wagmi, ethers.js, and OpenZeppelin. Use when writing smart contracts, debugging Solidity errors, setting up a Foundry project, writing Viem/Wagmi frontend code, or asking about ERC standards, gas optimization, upgradeable contracts, or any EVM development task. Triggers on: Solidity, Foundry, Hardhat, Viem, Wagmi, ethers.js, OpenZeppelin, ERC-20, ERC-721, ERC-4626, UUPS, proxy patterns, ABI, calldata, smart contract, deploy, cast, forge, anvil, or any EVM/blockchain development question.

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Web3 Docs

Current patterns and references for EVM development. Covers the full stack: contracts → testing → deployment → frontend integration.

Stack Coverage

| Layer | Tool | Reference | |-------|------|-----------| | Contracts | Solidity 0.8.x | references/solidity.md | | Framework | Foundry (forge/cast/anvil) | references/foundry.md | | Framework (alt) | Hardhat | references/hardhat.md | | Standards | OpenZeppelin 5.x | references/openzeppelin.md | | Standards | ERC-4626 (tokenized vaults) | references/erc4626.md | | Frontend (low-level) | Viem 2.x | references/viem.md | | Frontend (React) | Wagmi 2.x | references/wagmi.md | | Frontend (legacy) | ethers.js 6.x | references/ethers.md |

Quick Lookup

Starting a new Foundry project: See references/foundry.md → Project Setup

Starting a Hardhat project: See references/hardhat.md → Installation

Writing an ERC-20: See references/openzeppelin.md → ERC-20

Building a yield vault (ERC-4626): See references/erc4626.md → OpenZeppelin Implementation

First depositor attack on vaults: See references/erc4626.md → First Depositor Attack

Connecting a wallet in React: See references/wagmi.md → Quick Start

Reading contract state with Viem: See references/viem.md → Read Contracts

Common Solidity errors: See references/solidity.md → Error Reference

Deploying to Optimism/Base with Hardhat: See references/hardhat.md → hardhat.config.ts

Fetch Latest Docs

scripts/fetch-docs.js pulls live docs from official sources when the reference files may be stale.

node scripts/fetch-docs.js solidity      # Solidity docs
node scripts/fetch-docs.js foundry       # Foundry book
node scripts/fetch-docs.js viem          # Viem docs
node scripts/fetch-docs.js wagmi         # Wagmi docs
node scripts/fetch-docs.js openzeppelin  # OZ docs
node scripts/fetch-docs.js hardhat       # Hardhat docs
node scripts/fetch-docs.js erc4626       # ERC-4626 (OZ vault docs)

Gas Optimization Quick Rules

1. Use calldata instead of memory for read-only function params 2. Pack storage variables: multiple uint128 in one slot beats two separate uint256 3. unchecked blocks for arithmetic that can't overflow (saves ~30 gas/op) 4. immutable > constant > storage for values set once 5. Events are cheaper than storage for historical data 6. Batch operations: one tx touching N items beats N txs