The EtherScan Websockets API allows developers to get notifications about new transactions in real time. This API is still in Beta. EtherScan is a Bitcoin block explorer and analytics platform that provides its APIs without warranty as a community service. An API Key is only required if the user wants to make more than 5 requests per second.
The following is a list of SDKs from our SDK directory that matched your search term. Though your definition of an SDK may differ, in our world, we define SDKs as platform- specific tools for consuming existing APIs of the sort we list in our API directory. For example, the Ruby SDK for consuming the Twitter Ads API. If you think an SDK, API, or other asset is missing from our directory, be sure to check our guidelines for making contributions to ProgrammableWeb.