Expresscion is an open, cloud-friendly SCXML orchestration server.

Expresscion (formerly SCXMLD) provides Node.js express middleware which implements the State Machines as a Service (SMaaS) REST protocol.

Installation

Install PostgreSQL and Redis and set POSTGRES_URL and REDIS_URL in your environment.

You can clone this project boilerplate and run npm install; or follow the instructions.

Init a new Node.js project with npm init.

Create a new index.scxml file in the project root.

Install expresscion as package dependency: npm install --save expresscion

Add to package.json:

  "scripts": {
    "start": "node_modules/expresscion/bin/www index.scxml"
  },

Then run npm start, and visit http://localhost:8002/ in your web browser.

Optionally, install command-line tools: https://github.com/JacobeanRnD/smaas-cli

Deploy to the cloud

Expresscion is designed to work well with existing devops tools. Here is how to deploy to heroku:

heroku create my-app
heroku git:remote -a my-app
heroku addons:create heroku-postgresql
heroku addons:create heroku-redis
heroku config:set POSTGRES_URL=`heroku config:get DATABASE_URL`
heroku config:set HOST_URL=https://my-app.herokuapp.com
git push heroku master

Links

• State Machines as a Service: An SCXML Microservices Platform for the Internet of Things