# Build and dev **Authelia** is written in Typescript and built with [Authelia scripts](./authelia-scripts.md). In order to build and contribute to **Authelia**, you need to make sure Node with version >= 8 and < 10 and NPM is installed on your machine. ## Build **Authelia** is made of two parts: the frontend and the backend. The frontend is a [React](https://reactjs.org/) application written in Typescript and the backend is an express application also written in Typescript. The following command builds **Authelia** under dist/: authelia-scripts build And then you can also build the Docker image with: authelia-scripts docker build ## Development In order to ease development, Authelia uses the concept of [suites]. This is a kind of virutal environment for **Authelia**, it allows you to run **Authelia** in a complete environment, develop and test your patches. A hot-reload feature has been implemented so that you can test your changes in realtime. The next command will start the suite called [basic](../test/suites/basic/README.md): authelia-scripts suites start basic Then, edit the code and observe how **Authelia** is automatically updated. ### Unit tests To run the unit tests written in Mocha, run: authelia-scripts unittest ### Integration tests Integration tests also run with Mocha and are based on Selenium. They generally require a complete environment made of several components like redis, mongo and a LDAP to run. That's why [suites] have been created. At this point, the *basic* suite should already be running and you can run the tests related to this suite with the following command: authelia-scripts suites test [suites]: ./suites.md