diff --git a/.env b/.env
new file mode 100644
index 0000000..3247105
--- /dev/null
+++ b/.env
@@ -0,0 +1,2 @@
+UID=1000
+GID=1000
diff --git a/Gemfile b/Gemfile
index 4f4fa13..ef8f360 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,7 +2,22 @@
 
 source 'https://rubygems.org'
 
-gemspec
+if ENV['DEVEL'] == '1'
+  rails_ver = ENV.fetch('RAILS_VERSION')
+  gem 'rails', rails_ver
+
+  gem 'activeadmin', ENV.fetch('ACTIVEADMIN_VERSION')
+  gem 'activeadmin_dynamic_fields', path: './'
+
+  if rails_ver.start_with?('7.0')
+    gem 'concurrent-ruby', '1.3.4'
+    gem 'sqlite3', '~> 1.4'
+  else
+    gem 'sqlite3'
+  end
+else
+  gemspec
+end
 
 gem 'bigdecimal'
 gem 'mutex_m'
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..a6fc275
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,38 @@
+help:
+	@echo "Main targets: up / down / console / shell"
+
+# Docker commands
+down:
+	docker compose down
+
+up:
+	docker compose up
+
+attach:
+	docker compose attach app
+
+up_attach:
+	docker compose up -d && docker compose attach app
+
+cleanup:
+	docker container rm -f activeadmin_dynamic_fields_app && docker image rm -f activeadmin_dynamic_fields-app
+
+# Rails specific commands
+console:
+	docker compose exec -e "PAGER=more" app bin/rails console
+
+routes:
+	docker compose exec app bin/rails routes
+
+specs:
+	docker compose exec app bin/rspec --fail-fast
+
+# Other commands
+bundle:
+	docker compose exec app bundle
+
+shell:
+	docker compose exec -e "PAGER=more" app bash
+
+lint:
+	docker compose exec app bin/rubocop
diff --git a/README.md b/README.md
index d9b844c..a9b9bd0 100644
--- a/README.md
+++ b/README.md
@@ -234,17 +234,61 @@ end
 
 The link url is loaded via AJAX before opening the dialog.
 
+## Development
+
+Project created by [Mattia Roccoberton](http://blocknot.es), thanks also to the good guys that opened issues and pull requests from time to time.
+
+There 3 ways to interact with this project:
+
+1) Using Docker:
+
+```sh
+# Run rails server on the dummy app (=> http://localhost:3000 to access to ActiveAdmin):
+make up
+# Enter in a Rails console (with the dummy app started):
+make console
+# Enter in a shell (with the dummy app started):
+make shell
+# Run the linter on the project (with the dummy app started):
+make lint
+# Run the test suite (with the dummy app started):
+make specs
+# Remove container and image:
+make cleanup
+# To try different versions of Ruby/Rails/ActiveAdmin edit docker-compose.yml
+# For more commands please check the Makefile
+```
+
+2) Using Appraisal:
+
+```sh
+export RAILS_ENV=development
+# Install dependencies:
+bin/appraisal
+# Run server (or any command):
+bin/appraisal rails s
+# Or with a specific configuration:
+bin/appraisal rails80-activeadmin rails s
+```
+
+3) With a local setup:
+
+```sh
+# Dev setup (set the required envs):
+source extra/dev_setup.sh
+# Install dependencies:
+bundle update
+# Run server (or any command):
+bin/rails s
+# To try different versions of Rails/ActiveAdmin edit extra/dev_setup.sh
+```
+
 ## Do you like it? Star it!
 
 If you use this component just star it. A developer is more motivated to improve a project when there is some interest. My other [Active Admin components](https://github.com/blocknotes?utf8=✓&tab=repositories&q=activeadmin&type=source).
 
 Or consider offering me a coffee, it's a small thing but it is greatly appreciated: [about me](https://www.blocknot.es/about-me).
 
-## Contributors
-
-- [Mattia Roccoberton](http://blocknot.es): author
-- The good guys that opened issues and pull requests from time to time
-
 ## License
 
 The gem is available as open-source under the terms of the [MIT](LICENSE.txt).
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 0000000..8896ffd
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,25 @@
+services:
+  app:
+    container_name: 'activeadmin_dynamic_fields_app'
+    build:
+      context: .
+      dockerfile: ./extra/Dockerfile
+      # dockerfile: ./extra/Dockerfile_alpine
+      args:
+        # Debian-based Ruby image:
+        RUBY_IMAGE: ruby:3.4-slim
+        UID: ${UID}
+    environment:
+      ACTIVEADMIN_VERSION: ~> 3.3
+      RAILS_VERSION: ~> 8.0
+    user: "${UID}:${GID}"
+    ports:
+      - '3000:3000'
+    working_dir: '/app'
+    volumes:
+      - '.:/app'
+    stdin_open: true
+    tty: true
+    entrypoint:
+      - /bin/sh
+      - ./extra/entrypoint.sh
diff --git a/extra/Dockerfile b/extra/Dockerfile
new file mode 100644
index 0000000..ca9287b
--- /dev/null
+++ b/extra/Dockerfile
@@ -0,0 +1,21 @@
+ARG RUBY_IMAGE=ruby:3
+FROM ${RUBY_IMAGE}
+
+ARG UID
+
+ENV DEVEL=1
+ENV LANG=C.UTF-8
+ENV RAILS_ENV=development
+
+RUN apt-get update -qq
+RUN DEBIAN_FRONTEND=noninteractive apt-get install -yqq --no-install-recommends build-essential chromium libyaml-dev nano
+
+RUN gem install bundler
+RUN echo 'gem: --no-document' > /etc/gemrc
+
+RUN useradd -u ${UID} --shell /bin/bash app 
+RUN mkdir -p /home/app && chown -R app:app /home/app
+RUN chown -R app /usr/local/bundle 
+
+USER ${UID}
+COPY . /app
diff --git a/extra/Dockerfile_alpine b/extra/Dockerfile_alpine
new file mode 100644
index 0000000..e960879
--- /dev/null
+++ b/extra/Dockerfile_alpine
@@ -0,0 +1,18 @@
+FROM ruby:3.3-alpine
+
+ARG UID
+
+ENV DEVEL=1
+ENV LANG=C.UTF-8
+ENV RAILS_ENV=development
+
+RUN apk update && apk add --no-cache build-base chromium tzdata yaml-dev
+
+RUN gem install bundler
+RUN echo 'gem: --no-document' > /etc/gemrc
+
+RUN adduser -u ${UID} -D app 
+RUN mkdir -p /home/app && chown -R app:app /home/app
+RUN chown -R app /usr/local/bundle 
+
+COPY . /app
diff --git a/extra/README.md b/extra/README.md
deleted file mode 100644
index 87df75f..0000000
--- a/extra/README.md
+++ /dev/null
@@ -1,19 +0,0 @@
-# Development
-
-## Releases
-
-```sh
-# Update lib/activeadmin/dynamic_fields/version.rb with the new version
-# Update the gemfiles:
-bin/appraisal
-```
-
-## Testing
-
-```sh
-# Running specs using a specific configuration:
-bin/appraisal rails61-activeadmin29 rspec
-# Using latest activeadmin version:
-bin/appraisal rails60-activeadmin rspec
-# See gemfiles for more configurations
-```
diff --git a/extra/dev_setup.sh b/extra/dev_setup.sh
new file mode 100755
index 0000000..360b8ac
--- /dev/null
+++ b/extra/dev_setup.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+export DEVEL=1
+
+export RAILS_VERSION=8.0.2
+export ACTIVEADMIN_VERSION=3.3.0
+
+export RAILS_ENV=development
diff --git a/extra/entrypoint.sh b/extra/entrypoint.sh
new file mode 100644
index 0000000..0c9b41c
--- /dev/null
+++ b/extra/entrypoint.sh
@@ -0,0 +1,8 @@
+echo "> Install dependencies"
+rm -f Gemfile.lock && bundle install
+
+echo "> Run pending migrations"
+cd spec/dummy && bundle exec rails db:migrate
+
+echo "> Start Rails server"
+cd /app && rm -f spec/dummy/tmp/pids/server.pid && bundle exec rails s -b 0.0.0.0
diff --git a/spec/dummy/app/admin/tags.rb b/spec/dummy/app/admin/tags.rb
index d4749f1..09beb57 100644
--- a/spec/dummy/app/admin/tags.rb
+++ b/spec/dummy/app/admin/tags.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
 
 ActiveAdmin.register Tag do
+  permit_params :name
 end
diff --git a/spec/dummy/app/models/post.rb b/spec/dummy/app/models/post.rb
index faa8994..cd4a75f 100644
--- a/spec/dummy/app/models/post.rb
+++ b/spec/dummy/app/models/post.rb
@@ -14,7 +14,11 @@ class Post < ApplicationRecord
   has_many :post_tags, inverse_of: :post, dependent: :destroy
   has_many :tags, through: :post_tags
 
-  serialize :description, coder: JSON
+  if Gem::Version.new(Rails.version) >= Gem::Version.new('7.1')
+    serialize :description, coder: JSON
+  else
+    serialize :description, JSON
+  end
 
   after_initialize -> { self.description = {} if description.nil? }
 
@@ -50,13 +54,11 @@ def upper_title
     title.upcase
   end
 
-  class << self
-    def ransackable_associations(_auth_object = nil)
-      ["author", "author_profile", "post_tags", "tags"]
-    end
+  def self.ransackable_associations(_auth_object = nil)
+    ["author", "author_profile", "post_tags", "tags"]
+  end
 
-    def ransackable_attributes(_auth_object = nil)
-      ["author_id", "category", "created_at", "description", "dt", "id", "position", "published", "title", "updated_at"]
-    end
+  def self.ransackable_attributes(_auth_object = nil)
+    ["author_id", "category", "created_at", "description", "dt", "id", "position", "published", "title", "updated_at"]
   end
 end
diff --git a/spec/dummy/app/models/tag.rb b/spec/dummy/app/models/tag.rb
index 50a59bc..8660da8 100644
--- a/spec/dummy/app/models/tag.rb
+++ b/spec/dummy/app/models/tag.rb
@@ -3,4 +3,12 @@
 class Tag < ApplicationRecord
   has_many :post_tags, inverse_of: :tag, dependent: :destroy
   has_many :posts, through: :post_tags
+
+  def self.ransackable_associations(auth_object = nil)
+    ["post_tags", "posts"]
+  end
+
+  def self.ransackable_attributes(auth_object = nil)
+    ["created_at", "id", "name", "updated_at"]
+  end
 end
diff --git a/spec/dummy/config/database.yml b/spec/dummy/config/database.yml
index cfc4064..72b6a30 100644
--- a/spec/dummy/config/database.yml
+++ b/spec/dummy/config/database.yml
@@ -9,4 +9,5 @@ test:
 
 development:
   <<: *default
-  database: db/dev.sqlite3
+  database: db/development.sqlite3
+  schema_dump: schema_development.rb
diff --git a/spec/dummy/db/schema_development.rb b/spec/dummy/db/schema_development.rb
new file mode 100644
index 0000000..b55247a
--- /dev/null
+++ b/spec/dummy/db/schema_development.rb
@@ -0,0 +1,99 @@
+# This file is auto-generated from the current state of the database. Instead
+# of editing this file, please use the migrations feature of Active Record to
+# incrementally modify your database, and then regenerate this schema definition.
+#
+# This file is the source Rails uses to define your schema when running `bin/rails
+# db:schema:load`. When creating a new database, `bin/rails db:schema:load` tends to
+# be faster and is potentially less error prone than running all of your
+# migrations from scratch. Old migrations may fail to apply correctly if those
+# migrations use external dependencies or application code.
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema[8.0].define(version: 2018_06_07_053739) do
+  create_table "active_admin_comments", force: :cascade do |t|
+    t.string "namespace"
+    t.text "body"
+    t.string "resource_type"
+    t.integer "resource_id"
+    t.string "author_type"
+    t.integer "author_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["author_type", "author_id"], name: "index_active_admin_comments_on_author_type_and_author_id"
+    t.index ["namespace"], name: "index_active_admin_comments_on_namespace"
+    t.index ["resource_type", "resource_id"], name: "index_active_admin_comments_on_resource_type_and_resource_id"
+  end
+
+  create_table "active_storage_attachments", force: :cascade do |t|
+    t.string "name", null: false
+    t.string "record_type", null: false
+    t.integer "record_id", null: false
+    t.integer "blob_id", null: false
+    t.datetime "created_at", precision: nil, null: false
+    t.index ["blob_id"], name: "index_active_storage_attachments_on_blob_id"
+    t.index ["record_type", "record_id", "name", "blob_id"], name: "index_active_storage_attachments_uniqueness", unique: true
+  end
+
+  create_table "active_storage_blobs", force: :cascade do |t|
+    t.string "key", null: false
+    t.string "filename", null: false
+    t.string "content_type"
+    t.text "metadata"
+    t.bigint "byte_size", null: false
+    t.string "checksum", null: false
+    t.datetime "created_at", precision: nil, null: false
+    t.index ["key"], name: "index_active_storage_blobs_on_key", unique: true
+  end
+
+  create_table "authors", force: :cascade do |t|
+    t.string "name"
+    t.integer "age"
+    t.string "email"
+    t.datetime "created_at", precision: nil, null: false
+    t.datetime "updated_at", precision: nil, null: false
+  end
+
+  create_table "post_tags", force: :cascade do |t|
+    t.integer "post_id"
+    t.integer "tag_id"
+    t.datetime "created_at", precision: nil, null: false
+    t.datetime "updated_at", precision: nil, null: false
+    t.index ["post_id"], name: "index_post_tags_on_post_id"
+    t.index ["tag_id"], name: "index_post_tags_on_tag_id"
+  end
+
+  create_table "posts", force: :cascade do |t|
+    t.string "title"
+    t.string "state"
+    t.text "description"
+    t.integer "author_id"
+    t.string "category"
+    t.datetime "dt", precision: nil
+    t.float "position"
+    t.boolean "published"
+    t.datetime "created_at", precision: nil, null: false
+    t.datetime "updated_at", precision: nil, null: false
+    t.index ["author_id"], name: "index_posts_on_author_id"
+  end
+
+  create_table "profiles", force: :cascade do |t|
+    t.text "description"
+    t.integer "author_id"
+    t.datetime "created_at", precision: nil, null: false
+    t.datetime "updated_at", precision: nil, null: false
+    t.index ["author_id"], name: "index_profiles_on_author_id"
+  end
+
+  create_table "tags", force: :cascade do |t|
+    t.string "name"
+    t.datetime "created_at", precision: nil, null: false
+    t.datetime "updated_at", precision: nil, null: false
+  end
+
+  add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
+  add_foreign_key "post_tags", "posts"
+  add_foreign_key "post_tags", "tags"
+  add_foreign_key "posts", "authors"
+  add_foreign_key "profiles", "authors"
+end
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index 3ebd733..6e5f09d 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -26,7 +26,12 @@
 end
 
 RSpec.configure do |config|
-  config.fixture_path = Rails.root.join('spec/fixtures')
+  if Gem::Version.new(Rails.version) >= Gem::Version.new('7.1')
+    config.fixture_paths = [Rails.root.join('spec/fixtures')]
+  else
+    config.fixture_path = Rails.root.join('spec/fixtures')
+  end
+
   config.infer_spec_type_from_file_location!
   config.filter_rails_from_backtrace!
 
diff --git a/spec/support/capybara.rb b/spec/support/capybara.rb
index 15060c4..121f474 100644
--- a/spec/support/capybara.rb
+++ b/spec/support/capybara.rb
@@ -9,10 +9,10 @@
 
   Capybara::Cuprite::Driver.new(
     app,
-    window_size: [1600, 1280],
+    window_size: [1600, 1024],
     browser_options: browser_options,
-    process_timeout: 20,
-    timeout: 20,
+    process_timeout: 30,
+    timeout: 30,
     inspector: true,
     headless: !ENV['CUPRITE_HEADLESS'].in?(%w[n 0 no false])
   )