Lesli is an open-source framework built to create scalable, secure, and modular software products.

Built on Ruby on Rails, Hotwire, and Tailwind CSS, with support for SQLite and PostgreSQL, Lesli provides the infrastructure, architecture, and reusable components needed to build production-ready SaaS platforms faster.

Lesli is not a starter kit, admin panel, or boilerplate. It is a modular foundation that allows you to build applications using independent engines, shared infrastructure, and proven SaaS patterns.

With Lesli, you focus on features—not infrastructure.

Lesli core and its official engines provide:

• Modular architecture powered by standard Rails engines
• Flexible authentication, detailed privileges, and access control
• System auditing with activities and version tracking
• Attachments that can be added to any resource
• Full-text search across modules and records
• Multi-language support for both core and custom modules
• An architecture designed for long-term SaaS scalability and maintainability

• Try the online demo
• Run the Docker demo

• Ruby 3.2 or newer
• Rails 8.1
• SQLite, included in the default Rails application

Optional tooling:

• PostgreSQL for applications that prefer it over SQLite
• Node.js 20.x for advanced frontend development tasks

The default Lesli application can be built and run using only Rails and the Lesli gems.

Create a Rails application using Rails' default SQLite database:

rails new LesliApp
cd LesliApp

Add the gem and run the installation generator:

bundle add lesli
bin/rails generate lesli:install

Prepare the development database and verify the installation:

bin/rails lesli:db:prepare
bin/rails lesli:status

bin/rails server

Then visit http://127.0.0.1:3000/login.

To generate a complete demo application from the current development source:

rails new LesliDemo \
  --skip-bundle \
  -m https://raw.githubusercontent.com/LesliTech/Lesli/master/templates/template-dev.rb

To work on Lesli from a host Rails application, clone it into the application's engines directory:

cd RailsApp
mkdir -p engines
git clone https://github.com/LesliTech/Lesli.git engines/Lesli

Reference the local engine from the host application's Gemfile:

gem "lesli", path: "engines/Lesli"

Install and initialize the local engine:

bundle install
bin/rails generate lesli:install
bin/rails lesli:db:prepare
bin/rails server

For additional server configurations, use the standard Rails server options:

bin/rails server --binding=0.0.0.0
bin/rails server --environment=development

• Lesli website
• Documentation
• Contribution guide
• Releases and changelog

• X: @LesliTech
• hello@lesli.tech
• https://www.lesli.tech

Copyright (c) 2026, Lesli Technologies, S. A.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.

The complete license text is available in the license file.

The Open-Source SaaS Development Framework for Ruby on Rails.