A relayer can decide who can access their orders books and what orders they accept. At the moment, there are two main strategies relayers use.
A central matching strategy where the relayer only accepts orders where the taker is an address controlled by the relayer. When the relayer receives two orders on opposite sides of the market with overlapping prices, they automatically match both orders together.
An open order book strategy where the relayer accepts any order where the taker is allowed to be any address. Anyone can then take these orders from the book and complete them. However orders on opposite sides of the market with overlapping prices won’t automatically match.
Why use the open order book strategy?
We chose to use the open order book strategy rather than the central matching strategy for a variety of reasons.
Orders are able to be shared across relayers, dApps, and smart contracts. This allows us to participate in networked liquidity. As improvements are made to both Radar and the 0xprotocol, we’re confident that we will be able to provide the same experience as a central matching strategy while remaining much more decentralized and inclusive.