Challenge
Bitcoin Ordinals had no trustless trading mechanism. Existing NFT marketplaces relied on centralised order books and custodial escrow, antithetical to Bitcoin's ethos. The ecosystem needed an open, auditable standard that anyone could build on without permission.
Approach
I designed and built SADO, a Self-Authenticating Decentralised Orderbook protocol that uses IPFS for storing semi-signed transactions (PSBTs) with content identifiers published on-chain. The protocol supports any meta-protocol operating on UTXO data, not just Ordinals.
- 3-step instant purchasing: buyer signs PSBT, seller counter-signs, transaction broadcasts
- 6-step bidding mechanism for auction-style trading
- IPFS-based storage — no central server holds order state
- Published as open-source SDK at github.com/sadoprotocol
- Expanded into Sado.Space — a suite of tools and services
Outcome
SADO became the backbone of Ordzaar's trading engine and was adopted by third-party exchanges. The open protocol design proved that transparent, auditable trading infrastructure can exist natively on Bitcoin without centralised intermediaries.