add "api/v3/exchangeInfoLastUpdateTime" to reduce requests to "api/v3/exchangeInfo"

Add new endpoint api/v3/exchangeInfoLastUpdateTime to get last update time of changes in api/v3/exchangeInfo.

Currently, the user has no information if the data in api/v3/exchangeInfo was changed or not. Thus, the user always uses this endpoint. The use of this endpoint can be reduced a lot if the user gets api/v3/exchangeInfoLastUpdateTime. If the last update time is still the same, no new ping to exchangeInfo is needed.


  • reduces binance server load, because api/v3/exchangeInfo is only requested if user sees that api/v3/exchangeInfoLastUpdateTime has changed.
  • the user does not need to load api/v3/exchangeInfo (Weight: 10) and can cache exchangeInfo as long as exchangeInfoLastUpdateTime (Weight: 1) is not changed

Thanks for the feedback, please feel free to call the /exchangeInfo to get the latest symbol info.