Manual installation tutorial

In order to develop on decidim, you will need:

  • Git 2.34+

  • PostgreSQL 14.5+

  • Ruby 3.1.1

  • NodeJS 18.17.x

  • Npm 9.6.x

  • ImageMagick

  • Chrome browser and chromedriver.

The compatibility between the different versions of the components is the following:

Decidim version Ruby version Node version Status








Bug fixes and security updates




Bug fixes and security updates




Not maintained

We are starting with an Ubuntu 22.04.3 LTS. This is an opinionated guide, so you are free to use the technology that you are most comfortable. If you have any doubts and you are blocked you can go and ask on our chat room for developers.

We recommend to have at least some basic proficiency in GNU/Linux (i.e. how to use the command-line, packages, etc), networking knowledge, server administration, development in general, and some basic knowledge about software package managers. It would be great to have Ruby on Rails development basics (a good starting point is Getting Started with Ruby on Rails) and have some knowledge on how package libraries are working (we use bundler for handling ruby packages, and npm/yarn for handling javascript).

In this guide, we will see how to install rbenv, PostgreSQL, Node.js and, Decidim, and how to configure everything together for a development environment. Mind that if you want to make a production deployment with real users this guide is not enough, you should configure a web server (like nginx), backups, monitoring, etc. This is out of the scope of this guide, but you can follow the Platoniq guide.

1. Installing rbenv

First, we are going to install rbenv, for managing various ruby versions. You could also use rvm or asdf as alternatives on this step.

sudo apt update
sudo apt install -y build-essential curl git libssl-dev zlib1g-dev
git clone ~/.rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
source ~/.bashrc
git clone ~/.rbenv/plugins/ruby-build
rbenv install 3.1.1
rbenv global 3.1.1

2. Installing PostgreSQL

Now we are going to install PostgreSQL for the database:

sudo apt install -y postgresql libpq-dev
sudo -u postgres psql -c "CREATE USER decidim_app WITH SUPERUSER CREATEDB NOCREATEROLE PASSWORD 'thepassword'"

You need to change the password (in this example is "thepassword") and save it somewhere to configure it later with the application.

3. Installing Node.js

An important component for Decidim is Node.js and Yarn. With this commands you will install them:

sudo mkdir -p /etc/apt/keyrings
curl -fsSL | sudo gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg
echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list
sudo apt-get update && sudo apt-get install -y nodejs
curl -sL | gpg --dearmor | sudo tee /usr/share/keyrings/yarnkey.gpg >/dev/null
echo "deb [signed-by=/usr/share/keyrings/yarnkey.gpg] stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt-get update && sudo apt-get install -y yarn

4. Installing Decidim

Next, we need to install the decidim gem with its dependencies:

sudo apt install -y libicu-dev imagemagick
gem install decidim

Then we can create an application with the decidim executable, where decidim_application is your application name (ie DecidimBarcelona):

decidim decidim_application
cd decidim_application

We recommend that you save it all on Git.

git add .
git commit -m "Initial commit. Generated with Decidim"

5. Configure the database

Modify your secrets (see config/database.yml). For this you can use figaro, dotenv or rbenv-vars. You should always be careful of not uploading your plain secrets on git or your version control system. You can also upload the encrypted secrets, using the sekrets gem or if you are on Ruby on Rails greater than 5.1 you can do it natively.

For a development environment, and if you are using rbenv, we strongly recommend you to use the rbenv-vars to facilitate the edition of ENV vars.

First you will need to install the rbenv-vars plugin:

git clone "$(rbenv root)"/plugins/rbenv-vars

Then, in any folder above your decidim generated application, you need to create a file named .rbenv-vars and put your variables there:

cat << EOF > .rbenv-vars

Be careful where you put the .rbenv-vars file, as if you put it in the same folder of your decidim generated application, and if you use a version control system (like git, which we strongly recommend), then you should ignore this file (ie with the .gitignore file).

echo -e "\n\n# Ignore environment variables\n.rbenv-vars" >> .gitignore

6. Initializing your app for local development

Please refer to Empty database installation section if you want to setup your instance with an empty database (without any seeds).

We should now create your database. For a first local installation, we recommend to start with some example contents (also known as seeds).

bin/rails db:create db:migrate
bin/rails db:seed

This will also create some default data so you can start testing the app, with an administrator account with email and password decidim123456789

7. Start your web server

You can now start your server!


Visit http://localhost:3000 to see your app running. 🎉 🎉

With these steps you would only have an initial installation for trying Decidim, but it still needs lots of things to take in account. If you want a working production system then we recommend that you follow the Decidim Install guide by Platoniq.

Extra notes

Other user accounts that you will have in the seeds are:

  • To participate as a regular user, with email and password decidim123456789.

  • To manage the Multitenant and being able to log in at /system, with email and password decidim123456789.

The seed data will not be created in production environments, if you still want to do it (for instance, for a Demo or Staging server), run:

SEED=true rails db:seed