An order is a message passed into the 0x Settler to facilitate a trade (see How does 0x work?). The order types that we support include:
| Order Type | Summary | Supported Token Trade Types |
|---|---|---|
| Limit Orders | These are the standard 0x Order, which encodes a possible trade between a maker and a taker at a fixed price. Despite the name, these are not the same as traditional financial “limit orders.” In conventional markets, a limit order is an instruction to buy or sell an asset at a specified price or better. In contrast, a 0x Limit Order is an off-chain signed message representing a potential trade that can be filled on-chain by any taker, provided the price and conditions encoded in the order are met. | ERC20 ↔ ERC20 trade |
| RFQ Orders | These are a stripped-down version of standard limit orders, supporting fewer fields and a leaner settlement process. These orders are fielded just-in-time from market makers during the construction of a swap quote on 0x API and can be filled through the fillRfqOrder() function on the Exchange Proxy. See RFQ Order Structure. | ERC20 ↔ ERC20 trade |