Avail is a modular blockchain ecosystem built on Substrate, serving as a specialized data availability (DA) layer for rollups, sovereign chains, and off-chain scaling solutions. Avail uses erasure coding with KZG polynomial commitments in a 2D data availability sampling (DAS) scheme, enabling light clients to verify data availability without downloading full blocks, eliminating fraud proof requirements and honest majority assumptions. The ecosystem extends beyond DA with Avail Nexus, a ZK coordination rollup for proof aggregation and cross-rollup verification, and Avail Fusion for shared security via restaking.

Avail differentiates itself as a unification layer that addresses fragmentation by providing chain-agnostic DA infrastructure where rollups post to a shared base, enabling seamless cross-rollup interoperability and unified security guarantees. The platform benefits rollup developers seeking 90% lower DA costs compared to monolithic chains, sovereign chain builders requiring scalable validator bootstrapping without managing their own set, and multi-chain applications needing trustless state verification across ecosystems through a single proof verification hub.