What Is Composability?
Composability is DeFi's superpower — the ability for protocols to interact with each other permissionlessly, creating complex financial strategies by combining simple building blocks. Often called "money legos," composable protocols can be stacked: deposit ETH into Lido for stETH, use stETH as collateral on Aave to borrow USDC, and deposit USDC into a yield farm — all in a single transaction.
How Composability Works
Composability works because DeFi protocols share a common execution environment (e.g., the EVM) and use standardized token interfaces (ERC-20). Any protocol can read the state of and interact with any other protocol without permission. This open architecture enables innovation at a pace impossible in traditional finance, where integrations require partnerships and APIs.
Why It Matters for Traders
Composability creates exponential opportunity but also systemic risk. When protocols are deeply intertwined, a failure in one can cascade through the entire stack. The collapse of UST/LUNA demonstrated how composability amplifies contagion — dozens of protocols built on top of Anchor's yield collapsed simultaneously. Understanding the composability chain of any DeFi strategy is essential for assessing its true risk.
