所有辅助函数都有一个chain选项来指定从哪个区块链获取数据。 以下是chain选项当前支持的值。 任何“Lookup Values”都将匹配相应的链。
如果未指定，该链将默认为以太坊主网。
| Chain | Lookup Values |
| Ethereum Mainnet | eth, mainnet, 0x1 |
| Ropsten (Ethereum Testnet) | testnet, ropsten, 0x3 |
| Rinkeby (Ethereum Testnet) | rinkeby, 0x4 |
| Goerli (Ethereum Testnet) | goerli, 0x5 |
| Kovan (Ethereum Testnet) | kovan, 0x2a |
| Binance Smart Chain Mainnet | bsc, binance, binance smart chain, 0x38 |
| Binance Smart Chain Testnet | bsc testnet, binance testnet, binance smart chain testnet, 0x61 |
| Polygon (Matic) Mainnet | matic, polygon, 0x89 |
| Mumbai (Matic Testnet) | mumbai, matic testnet, polygon testnet, 0x13881 |
| Avalanche Mainnet | avalanche, 0xa86a |
| Avalanche Testnet | avalanche testnet, 0xa869 |
| Fantom Mainnet | fantom, 0xfa |
| Local Dev Chain (Ganache, Hardhat) (doesn't work currently with Web3API) | ganache, hardhat, localdevchain, local devchain ,dev, 0x539 |
本地开发链（Ganache、Hardhat）目前不适用于 Web3API。