Code structure

You might be tempted to contribute to StackStorm by this point. Let us walk you through the code a bit.

StackStorm/st2 Repo

StackStorm is made up of individual services: st2auth, st2api, st2rulesengine, st2sensorcontainer, st2actionrunner, st2notifier.

StackStorm also has a CLI and client library. Code for all these services and components are laid out in different folders in the repo root.


Common code that contains DB and API data models, utility functions and common service code that all of StackStorm needs. Each service package (deb/rpm) has a dependency on the st2common package. So if you want common code that should be shared amongst components written, you’d add them here.


This folder contains code for API controllers in StackStorm. APIs are versioned and so are controllers. Experimental controllers are added to exp folder inside st2api and when they mature, they are moved to folders containing versioned controllers.


Contains code for st2auth endpoint. Since this endpoint needs to deployed separately than st2api, it is available as a separate app.


Contains code for action runners. A new runner written for StackStorm would be added to st2actions/st2actions/runners. Also, this folder contains the code for worker node that scans RabbitMQ for incoming executions.

Notifier and results tracker are also part of this code base. Notifier is the component that sends notification triggers and action triggers at the end of action execution. Results tracker is an advanced async results querier for certain kind of runners like 3rd party integrations, where execution of an action is kicked off and you have to poll the integrations APIs to collect results.


Contains code for both StackStorm client library and StackStorm CLI bundled into one folder. We will eventually split them.


If you are familiar with st2-submit-debug-info tool, the code for that is present in this folder. This tool provides a way to share logs and other info with a StackStorm engineer for troubleshooting.


Contains code for both sensor container and rules engine.


Shared code containing fixtures and test utilities that helps in unit and integration testing for all StackStorm components.