The 0x API is designed to make it easy for DeFi developers like you to tap into both off-chain and on-chain DEX liquidity in a fast, reliable, and easy to use way so you can focus on what matters: your product. As of February 12th, 2020, the /swap/v1 endpoint supports 0x Protocol v4.
This version of the 0x Protocol is the most powerful update made to the protocol to date, turning it into the most gas-efficient DEX. As a result, users of applications built with 0x API can expect more gas efficient orders (up to 70% gas saved for RFQ orders and 10% for limit orders) and even better prices from 0x professional market makers.
If you are building with 0x API /swap/v1 , here’s what you need to know:New allowanceTarget
The default allowanceTarget returned by /swap/v1 has changed to 0xdef1c0ded9bec7f1a1670819833240f027b25eff. This allows us to lower costs for your end users by a measurable amount:
However, we understand if you don’t want to migrate your users just yet. This is a soft change and the old allowance (0xf740b67da229f2f10bcbd38a7979992fcc71b8eb) will continue working until March 31st — when we deprecate it.Upgrade takerAddress ...