diff --git a/CHANGES.md b/CHANGES.md
new file mode 100644
index 00000000..0a443c1c
--- /dev/null
+++ b/CHANGES.md
@@ -0,0 +1,29 @@
+# Changes from upstream (DiD, LLC)
+
+This is a branding patch layer on top of docusealco/docuseal, maintained
+as a separate `did-branding` branch so it can be rebased against future
+upstream releases without editing upstream files directly. Base license
+is unchanged: AGPLv3, including the original DocuSeal attribution
+requirement in `LICENSE_ADDITIONAL_TERMS`.
+
+## did-branding branch
+
+- `tailwind.config.js`, `tailwind.dynamic.config.js`: replaced the default
+  daisyui theme's color palette with DiD's brand palette (Deep Navy
+  #022647, Lime Green #9BC73C, Light Blue #75B9FC, Soft Grey #CCD6D0),
+  and added a `heading` font family slot.
+- `app/views/layouts/_head_tags.html.erb`: added Google Fonts links for
+  Monda and Montserrat.
+- `app/javascript/application.scss`, `app/javascript/form.scss`: applied
+  the Monda/Montserrat heading font to h1-h6.
+- `app/views/shared/_logo.html.erb`: recolored the DocuSeal logo mark
+  from its default orange (#e97a42) to DiD's lime green (#9BC73C). The
+  logo shape and "DocuSeal" text attribution are unchanged, per
+  `LICENSE_ADDITIONAL_TERMS`.
+- `config/routes.rb`, `app/controllers/source_controller.rb`,
+  `app/views/source/index.html.erb`: added an unauthenticated `/source`
+  route publishing this instance's corresponding source (AGPLv3 §13),
+  this CHANGES.md, and the bundled LICENSE / LICENSE_ADDITIONAL_TERMS text.
+
+No application logic, data handling, or upstream file content was
+otherwise modified.
diff --git a/app/controllers/source_controller.rb b/app/controllers/source_controller.rb
new file mode 100644
index 00000000..f64238ff
--- /dev/null
+++ b/app/controllers/source_controller.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+# AGPLv3 Section 13 (network use) compliance: this route stays reachable
+# without sign-in or setup, unauthenticated, so the corresponding source
+# is available before any user interacts with the deployed instance.
+class SourceController < ApplicationController
+  skip_before_action :authenticate_user!, raise: false
+  skip_before_action :maybe_redirect_to_setup, raise: false
+  skip_authorization_check
+
+  layout 'plain'
+
+  SOURCE_REPO_URL = ENV.fetch('DID_SOURCE_REPO_URL', 'https://repo.diditvi.com/didadmin/docuseal')
+  SOURCE_COMMIT = ENV.fetch('DID_SOURCE_COMMIT', 'unknown')
+
+  def index
+    @source_repo_url = SOURCE_REPO_URL
+    @source_commit = SOURCE_COMMIT
+    @license = File.read(Rails.root.join('LICENSE'))
+    @additional_terms = File.read(Rails.root.join('LICENSE_ADDITIONAL_TERMS'))
+    @changes = File.read(Rails.root.join('CHANGES.md'))
+  end
+end
diff --git a/app/views/source/index.html.erb b/app/views/source/index.html.erb
new file mode 100644
index 00000000..b9c24bcf
--- /dev/null
+++ b/app/views/source/index.html.erb
@@ -0,0 +1,31 @@
+<div class="max-w-3xl mx-auto p-8 space-y-8">
+  <div>
+    <h1 class="text-3xl font-bold mb-2">Source Code</h1>
+    <p>
+      This is a DiD-branded build of
+      <a href="https://github.com/docusealco/docuseal" class="link" target="_blank" rel="noopener">DocuSeal</a>,
+      licensed under the GNU Affero General Public License v3 (AGPLv3).
+      In accordance with AGPLv3 Section 13, the complete corresponding source
+      for this exact running instance is published here:
+    </p>
+    <p class="mt-2">
+      <a href="<%= @source_repo_url %>" class="link link-primary text-lg" target="_blank" rel="noopener"><%= @source_repo_url %></a>
+    </p>
+    <p class="text-sm opacity-70 mt-1">Running commit: <code><%= @source_commit %></code></p>
+  </div>
+
+  <div>
+    <h2 class="text-xl font-bold mb-2">Changes from upstream</h2>
+    <pre class="whitespace-pre-wrap text-sm bg-base-200 rounded-lg p-4"><%= @changes %></pre>
+  </div>
+
+  <div>
+    <h2 class="text-xl font-bold mb-2">License (AGPLv3)</h2>
+    <pre class="whitespace-pre-wrap text-xs bg-base-200 rounded-lg p-4 max-h-96 overflow-y-auto"><%= @license %></pre>
+  </div>
+
+  <div>
+    <h2 class="text-xl font-bold mb-2">Additional Terms</h2>
+    <pre class="whitespace-pre-wrap text-sm bg-base-200 rounded-lg p-4"><%= @additional_terms %></pre>
+  </div>
+</div>
diff --git a/config/routes.rb b/config/routes.rb
index ad8505e5..81fa99f3 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -11,6 +11,8 @@ Rails.application.routes.draw do
 
   root 'dashboard#index'
 
+  get '/source', to: 'source#index'
+
   get 'up' => 'rails/health#show'
   get 'manifest' => 'pwa#manifest'