Polygon Amoy is a testnet designed for developers to deploy, test, and optimize smart contracts in a cost-effective environment before launching them on the Polygon mainnet. Utilizing Ethereum's Sepolia testnet as its root chain, Amoy offers a similar execution environment to the mainnet but with reduced security and decentralization, providing a practical platform for developers to fine-tune their applications without incurring gas fees. Developers can obtain free testnet MATIC for powering transactions and testnet LINK for utilizing Chainlink services through the Chainlink Amoy Faucet. Additionally, the testnet includes resources such as faucets, tooling, and a block explorer to support development efforts. Amoy replaces the previous Polygon Mumbai testnet, which relied on the now-deprecated Ethereum Goerli testnet, and can be added to MetaMask wallets by entering specific network configurations.