PowerAPI is a middleware toolkit for building software-defined power meters. Software-defined power meters are configurable software libraries that can estimate the power consumption of software in real-time. PowerAPI supports the acquisition of raw metrics from a wide diversity of sensors (eg., physical meters, processor interfaces, hardware counters, OS counters) and the delivery of power consumptions via different channels (including file system, network, web, graphical). As a middleware toolkit, PowerAPI offers the capability of assembling power meters «à la carte» to accommodate user requirements.

PowerAPI is an open-source project developed by the Spirals research group (University of Lille 1 and Inria) and is completely written in Scala (v2.11), using the Akka library (v2.3). Configuration part is managed by the Typesafe Config (integrated version from the Akka library). PowerAPI project is fully managed with sbt.