OpenRelay.js is a JavaScript library for interfacing with OpenRelay.xyz and other 0x Standard Relayer API providers.
It is currently in pre-release development, and targets an earlier draft of the Standard Relayer API. It should work with OpenRelay.xyz, but will not work with other Relayers until a future update. It is intended that code written to OpenRelay.js should continue to work after the switch to the finalized Standard Relayer API, but we can't make such guarantees at this point.