Device OS 6.1.0 is now available with new features, bug fixes, and improvements. Most exciting is the device side Ledger feature addition that allows a request for a ledger from a device. With Device-to-Cloud Ledger, you will be able to save sensor data on the device itself and sync it to the cloud when the device is connected. Applications can access this data through the Particle API and Logic Functions, enabling seamless integration and utilization of the stored information.

Release notes can be found here on Github.