On-chain Contract Library
Compose takes a different approach.
Compose provides a set of reusable on-chain contracts that already exist on blockchains. You don't need to deploy or manage them yourself. The heavy lifting has been done for you.
Why This Matters
Traditionally, you would extend functionality through inheritance at the source-code level, for example:
contract ERC20Permit is ERC20 { ... }
This approach tightly couples code and forces every variant to be redeployed as a new contract, resulting in the same code being duplicated and deployed across countless projects.
Compose changes that!
Instead of inheritance, it uses on-chain composition — combining existing deployed facets and your own custom facets inside a single diamond.
This reduces duplication, improves upgradeability, and makes smart contract systems more flexible and maintainable.
For your next project, instead of deploying new contracts, simply use the existing on-chain contracts provided by Compose.