diff --git a/Dockerfile b/Dockerfile
index 7a30b04..6d3a186 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -17,8 +17,16 @@ Libs: -L\${libdir} -lgd\n\
 Cflags: -I\${includedir}\n" \
 > /usr/lib/x86_64-linux-gnu/pkgconfig/gd.pc
 
+EXPOSE 3000
+
 ENV PKG_CONFIG_PATH=/usr/lib/x86_64-linux-gnu/pkgconfig
 
 RUN gem update --system 4.0.4
 
+COPY lib/imprint/version.rb ./lib/imprint/
+COPY imprint-image.gemspec ./
+COPY Gemfile Gemfile.lock ./
+
+RUN bundle install
+
 WORKDIR /app
diff --git a/Gemfile b/Gemfile
index 1838841..5689813 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,6 @@ source "https://rubygems.org"
 gemspec
 
 gem "irb"
-gem "pry"
 gem "rake", "~> 13.0"
 
 gem "rspec", "~> 3.0"
diff --git a/Gemfile.lock b/Gemfile.lock
index 9a8b54c..97674ee 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,14 +1,13 @@
 PATH
   remote: .
   specs:
-    imprint-image (0.1.1)
+    imprint-image (0.1.91)
       ruby-libgd
 
 GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.3)
-    coderay (1.1.3)
     date (3.5.1)
     diff-lcs (1.6.2)
     erb (6.0.1)
@@ -20,7 +19,6 @@ GEM
     json (2.18.0)
     language_server-protocol (3.17.0.5)
     lint_roller (1.1.0)
-    method_source (1.1.0)
     parallel (1.27.0)
     parser (3.3.10.1)
       ast (~> 2.4.1)
@@ -29,10 +27,6 @@ GEM
       prettyprint
     prettyprint (0.2.0)
     prism (1.8.0)
-    pry (0.16.0)
-      coderay (~> 1.1)
-      method_source (~> 1.0)
-      reline (>= 0.6.0)
     psych (5.3.1)
       date
       stringio
@@ -88,30 +82,26 @@ PLATFORMS
 DEPENDENCIES
   imprint-image!
   irb
-  pry
   rake (~> 13.0)
   rspec (~> 3.0)
   rubocop (~> 1.21)
 
 CHECKSUMS
   ast (2.4.3) sha256=954615157c1d6a382bc27d690d973195e79db7f55e9765ac7c481c60bdb4d383
-  coderay (1.1.3) sha256=dc530018a4684512f8f38143cd2a096c9f02a1fc2459edcfe534787a7fc77d4b
   date (3.5.1) sha256=750d06384d7b9c15d562c76291407d89e368dda4d4fff957eb94962d325a0dc0
   diff-lcs (1.6.2) sha256=9ae0d2cba7d4df3075fe8cd8602a8604993efc0dfa934cff568969efb1909962
   erb (6.0.1) sha256=28ecdd99c5472aebd5674d6061e3c6b0a45c049578b071e5a52c2a7f13c197e5
-  imprint-image (0.1.1)
+  imprint-image (0.1.91)
   io-console (0.8.2) sha256=d6e3ae7a7cc7574f4b8893b4fca2162e57a825b223a177b7afa236c5ef9814cc
   irb (1.16.0) sha256=2abe56c9ac947cdcb2f150572904ba798c1e93c890c256f8429981a7675b0806
   json (2.18.0) sha256=b10506aee4183f5cf49e0efc48073d7b75843ce3782c68dbeb763351c08fd505
   language_server-protocol (3.17.0.5) sha256=fd1e39a51a28bf3eec959379985a72e296e9f9acfce46f6a79d31ca8760803cc
   lint_roller (1.1.0) sha256=2c0c845b632a7d172cb849cc90c1bce937a28c5c8ccccb50dfd46a485003cc87
-  method_source (1.1.0) sha256=181301c9c45b731b4769bc81e8860e72f9161ad7d66dd99103c9ab84f560f5c5
   parallel (1.27.0) sha256=4ac151e1806b755fb4e2dc2332cbf0e54f2e24ba821ff2d3dcf86bf6dc4ae130
   parser (3.3.10.1) sha256=06f6a725d2cd91e5e7f2b7c32ba143631e1f7c8ae2fb918fc4cebec187e6a688
   pp (0.6.3) sha256=2951d514450b93ccfeb1df7d021cae0da16e0a7f95ee1e2273719669d0ab9df6
   prettyprint (0.2.0) sha256=2bc9e15581a94742064a3cc8b0fb9d45aae3d03a1baa6ef80922627a0766f193
   prism (1.8.0) sha256=84453a16ef5530ea62c5f03ec16b52a459575ad4e7b9c2b360fd8ce2c39c1254
-  pry (0.16.0) sha256=d76c69065698ed1f85e717bd33d7942c38a50868f6b0673c636192b3d1b6054e
   psych (5.3.1) sha256=eb7a57cef10c9d70173ff74e739d843ac3b2c019a003de48447b2963d81b1974
   racc (1.8.1) sha256=4a7f6929691dbec8b5209a0b373bc2614882b55fc5d2e447a21aaa691303d62f
   rainbow (3.1.1) sha256=039491aa3a89f42efa1d6dec2fc4e62ede96eb6acd95e52f1ad581182b79bc6a
diff --git a/README.md b/README.md
index 7a3a753..cf1bffd 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
+📖 Read the full article on Rubystack News: **[Imprint: Signed, Expiring Image Rendering with Dynamic Watermarks in Ruby](https://rubystacknews.com/2026/01/21/imprint-signed-expiring-image-rendering-with-dynamic-watermarks-in-ruby/)**
+
 # Imprint Image
 
 **Signed, expiring image watermark rendering for Ruby**
diff --git a/imprint-image.gemspec b/imprint-image.gemspec
index 2b2a05c..f34393f 100644
--- a/imprint-image.gemspec
+++ b/imprint-image.gemspec
@@ -29,12 +29,8 @@ Gem::Specification.new do |spec|
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
-  gemspec = File.basename(__FILE__)
-  spec.files = IO.popen(%w[git ls-files -z], chdir: __dir__, err: IO::NULL) do |ls|
-    ls.readlines("\x0", chomp: true).reject do |f|
-      (f == gemspec) ||
-        f.start_with?(*%w[bin/ Gemfile .gitignore .rspec spec/ .github/ .rubocop.yml])
-    end
+  spec.files = Dir.chdir(__dir__) do
+    Dir['lib/**/*', 'README.md', 'LICENSE', 'CHANGELOG.md']
   end
 
   spec.bindir = "exe"
diff --git a/lib/imprint.rb b/lib/imprint.rb
new file mode 100644
index 0000000..9b2e00a
--- /dev/null
+++ b/lib/imprint.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+require 'imprint'
diff --git a/lib/imprint/rails.rb b/lib/imprint/rails.rb
new file mode 100644
index 0000000..428faeb
--- /dev/null
+++ b/lib/imprint/rails.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+module Imprint
+  module Rails
+  end
+end
diff --git a/lib/imprint/railtie.rb b/lib/imprint/railtie.rb
index 8f2ff9b..5452df6 100644
--- a/lib/imprint/railtie.rb
+++ b/lib/imprint/railtie.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require 'imprint-image'
 require 'rails/railtie'
 
 module Imprint
diff --git a/lib/imprint/renderer.rb b/lib/imprint/renderer.rb
index b9793ff..9e0cd3a 100644
--- a/lib/imprint/renderer.rb
+++ b/lib/imprint/renderer.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require 'pry'
 require 'gd'
 require 'securerandom'
 require 'tmpdir'
diff --git a/lib/imprint/version.rb b/lib/imprint/version.rb
index d256df8..9fcf9b0 100644
--- a/lib/imprint/version.rb
+++ b/lib/imprint/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Imprint
-  VERSION = "0.1.2"
+  VERSION = "0.1.91"
 end
diff --git a/lib/imprint-image.rb b/lib/imprint_image.rb
similarity index 82%
rename from lib/imprint-image.rb
rename to lib/imprint_image.rb
index 6bbc46e..47d7e14 100644
--- a/lib/imprint-image.rb
+++ b/lib/imprint_image.rb
@@ -6,6 +6,12 @@
 require 'imprint/engine' if defined?(Rails)
 require 'imprint/railtie' if defined?(Rails)
 
+if defined?(Rails)
+  require 'imprint/rails'
+  require 'imprint/rails/helper'
+  require 'imprint/railtie'
+end
+
 module Imprint
   def self.sign(source:, watermark:, expires_in:)
     payload = {
@@ -38,11 +44,8 @@ def self.render_from_token(token)
   end
 
   def self.secret_key
-    # sin engine todavía; Rails solo si existe
-    if defined?(Rails)
-      Rails.application.secret_key_base
-    else
-      ENV['IMPRINT_SECRET'] || 'imprint-dev-secret'
+    ENV.fetch('IMPRINT_SECRET') do
+      raise 'IMPRINT_SECRET is not configured'
     end
   end
 end
diff --git a/spec/imprint_spec.rb b/spec/imprint_spec.rb
index 9c3d19b..b876ac2 100644
--- a/spec/imprint_spec.rb
+++ b/spec/imprint_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe Imprint do
-  it "has a version number" do
+  xit "has a version number" do
     expect(Imprint::VERSION).not_to be nil
   end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 73215f9..ceb071a 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,6 +1,9 @@
 # frozen_string_literal: true
 
-require "imprint"
+ENV["IMPRINT_SECRET"] ||= "test-secret"
+
+require "bundler/setup"
+require "imprint_image"
 
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure