Last year, Google introduced a preview version of the Local Home SDK. The SDK integrates with Google Assistant and enables it to run services local to the Google Assistant rather than in the cloud. In turn, Google Assistant users experience less latency and more reliability. Now, the Local Home SDK is out of developer preview with the release of v1.0.
Developers can submit local fulfillment apps associated with smart home Actions. The local fulfillment option is available through the Actions console. To learn more about getting started with the Local Home SDK, check out Google's Introduction to Local Home SDK and developer guide.
The Local Home SDK discovers local devices over Wi-Fi using the mDNS, UDP, or UPnP protocols. Once a local connection is made, apps send commands to devices using TCP, UDP, or HTTP. If a local path is not found, the action falls back on cloud fulfillment.
To further assist developers, Google has published samples and an API reference. Google encourages developers to build their first fulfillment app with codelab. Local Home is in its first version, and issues are bound to pop up. Google encourages feedback and bug reporting through the issue tracker.