Spool is a permissionless DeFi middleware ‘toolkit’ that allows users to create fully customised, automated, and diversified yield farming portfolios with a single deposit. Select your favourite yield generators from a list of supported protocols and create a diversified portfolio based on your individual risk appetite… All accessible through a single deposit address. After depositing, Spool automatically manages deposits to optimize risk/reward for individual users within the given terms under which their capital was deposited — Spool regularly rebalances liquidity between yield generating DeFi protocols, while taking individual user’s risk tolerance and array of selected strategies into account. Spool represents the next evolutionary step for DeFi on Ethereum by allowing for diversification, compounding, and rebalancing at affordable gas prices via a buffer system and transaction batching. It enables builders to easily access and combine existing and new DeFi legos, creating possibilities for novel user-facing products that leverage the power of all of DeFi instead of just a few individual primitives. Spool is designed to serve as the backend for DeFi-powered financial products and applications.