what's The Mempool Open Source Project?

The Mempool Open Source Project operates mempool.space, a leading Bitcoin explorer focused on real-time mempool visualization and network insights. It displays unconfirmed transactions, projected blocks, fee rates in sat/vB, recent replacements (RBF), and block details including miner information. Users can track transaction status, estimate fees, accelerate stuck transactions via Mempool Accelerator, and explore the full Bitcoin ecosystem without relying on centralized services. As an open-source initiative, it pioneered mempool projection as half-filled blocks, distinguishing it from traditional block explorers. Every Bitcoin node maintains its own mempool, and mempool.space provides tools to view, search, and analyze this data alongside blockchain history. Developers access APIs for integration, and community-run instances extend its reach, emphasizing decentralization and transparency in Bitcoin infrastructure.

Mempool's accelerator feature failed March 12, preventing user transaction acceleration.