Envelop is a flexible cross-chain toolset able to give any NFT new functionality (economic set-up, on-chain royalties, rental mechanism, time/value/event-locks), protection of devaluation, and anti-fraud system. Envelop's long-term aim is cross-chain tokenization of payment channels (rollups) to intensify unused liquidity. Envelop consists of three parts: (1.) Protocol to add the digital assets inside NFTs and set new features; (2.) Oracle to score the collateral and assess the quality of assets inside NFTs; (3.)Index to hedge the position to the whole NFT market — becomes one of the first decentralized and collateralized simultaneously market indexes for NFT and related assets.