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Utility and extension code for the Esper Complex Event Processing Engine.
branch: master

Esper Extension Library

Esper is an OSS Complex Event Processing (CEP) library which enables anyone to build high-throughput, low-latency, real-time event processing applications.

The Esper extension library is a set of utility plugins you can use in your Esper implementation.

At version 0.1.0 it is stable although it still does not have many extensions. Currently it mostly has a plugin view that calculates the TRIX index over a value in an event stream. This index allows you, in fact, to calculate the tendency of that value - is it trending up, down, stable?

There are plans to include further extensions for things like:

  • Named window persistance and recovery after restarting
  • Catalog of technical analysis plugin windows and aggregation functions (great for Algorithmic Trading but also for general time series trend analysis)
  • EPL rule annotations
  • (many more...)

Suggestions and contributions are welcome :-)

Getting Started

You can build your own JAR or download a prebuilt one. You include the JAR in your classpath and configure the plugin windows and functions in your esper configuration files. For more information go here.

Building JAR:

Build scripts are just plain-old Ant. To generate a JAR just do:

ant dist


This project still hasn't been Mavenified but I plan to do it as soon as I have some time. For the time being, if you are using Maven just include the following in your pom.xml:



esper-ext is open source software released under the MIT License (see LICENSE file). I will be happy to integrate patches from anyone willing to contribute.

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