Install jets via RubyGems.

gem install jets

Prerequisites and Dependencies

Jets works on macosx and linux variants. Jets does not work on windows. For windows, recommend considering Cloud9 IDE. There are some nice advantages like Faster Development.


Jets supports Ruby 2.5 and Ruby 2.7, which are the Ruby versions supported by AWS Lambda. Patch variants of it should work. More details: Using Different Ruby Versions.


For apps with HTML pages, jets uses webpacker to compile assets, which requires yarn. Node version manager, nvm, is recommended if you want to manage node versions.

curl -o- | bash
# note follow the instructions after the curl command to source nvm
nvm install v12.13.0
nvm alias default node # sets the default version

Once node is installed, install yarn with:

npm install -g yarn

You can use any version of yarn that works with webpacker. If you run into webpacker issues, try upgrading node and yarn to the latest version. Also, upgrading the yarn.lock file with yarn upgrade sometimes helps.


By default, when you run a jets new command, Jets calls bundle install and attempts to install the mysql2 gem. If you want to use PostgreSQL, run jets new --database=postgresql. Make sure that you have MySQL or PostgreSQL installed beforehand.

If you don’t need an ORM database adapter, or want to use another database, use the jets new --no-database option. You can subsequently add any datastore adapter gem to the Gemfile, and run bundle install.

Here are the instructions to install MySQL and PostgreSQL:


brew install mysql # macosx
yum install -y mysql-devel # amazonlinux2 and redhat variants
apt-get install -y libmysqlclient-dev # ubuntu and debian variants


brew install postgresql # macosx
yum install -y postgresql-devel # amazonlinux2 and redhat variants
apt-get install libpq-dev # ubuntu and debian variants


The AWS CLI is required. You can install the AWS CLI. Here’s a few ways to install it.

pip install awscli --upgrade --user

Or with Homebrew on macOS:

brew install awscli

Then configure it.

aws configure

IAM policy, group, and user

The IAM user you use to run the jets deploy command needs a minimal set of IAM policies in order to deploy a Jets application. Follow the Minimal Deploy Policy IAM Policy to create the policy, group, and user. Use the user’s credentials to configure the aws-cli above.