diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a6968c..4fa24e2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [1.2.1] - 2026-03-17
+
+### Added
+
+- Support for callable values (Proc/Lambda) in `username` and `password` configuration, enabling use with `Rails.application.credentials` and other deferred sources ([#31](https://github.com/vishaltps/solid_queue_monitor/issues/31))
+- Initializer template now shows ENV variable and Lambda examples for credentials
+
 ## [1.2.0] - 2026-03-07
 
 ### Changed
diff --git a/Gemfile.lock b/Gemfile.lock
index 2932e71..00bdca7 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    solid_queue_monitor (1.2.0)
+    solid_queue_monitor (1.2.1)
       rails (>= 7.0)
       solid_queue (>= 0.1.0)
 
diff --git a/README.md b/README.md
index 7ee1038..bffb890 100644
--- a/README.md
+++ b/README.md
@@ -104,9 +104,11 @@ SolidQueueMonitor.setup do |config|
   config.authentication_enabled = false
 
   # Set the username for HTTP Basic Authentication (only used if authentication is enabled)
+  # Supports static values, ENV variables, or callables (Proc/Lambda)
   config.username = 'admin'
 
   # Set the password for HTTP Basic Authentication (only used if authentication is enabled)
+  # Supports static values, ENV variables, or callables (Proc/Lambda)
   config.password = 'password'
 
   # Number of jobs to display per page
@@ -141,7 +143,21 @@ By default, Solid Queue Monitor does not require authentication to access the da
 For production environments, it's strongly recommended to enable authentication:
 
 1. **Enable authentication**: Set `config.authentication_enabled = true` in the initializer
-2. **Configure secure credentials**: Set `username` and `password` to strong values in the initializer
+2. **Configure secure credentials** using any of these approaches:
+
+```ruby
+# Static values
+config.username = 'admin'
+config.password = 'secure_password'
+
+# Environment variables
+config.username = ENV['SOLID_QUEUE_MONITOR_USERNAME']
+config.password = ENV['SOLID_QUEUE_MONITOR_PASSWORD']
+
+# Rails credentials (use a lambda for deferred evaluation)
+config.username = -> { Rails.application.credentials.dig(:solid_queue_monitor, :username) }
+config.password = -> { Rails.application.credentials.dig(:solid_queue_monitor, :password) }
+```
 
 ## Usage
 
diff --git a/lib/generators/solid_queue_monitor/templates/initializer.rb b/lib/generators/solid_queue_monitor/templates/initializer.rb
index 3e56296..14a0ae0 100644
--- a/lib/generators/solid_queue_monitor/templates/initializer.rb
+++ b/lib/generators/solid_queue_monitor/templates/initializer.rb
@@ -7,9 +7,13 @@
 
   # Set the username for HTTP Basic Authentication (only used if authentication is enabled)
   # config.username = 'admin'
+  # config.username = ENV['SOLID_QUEUE_MONITOR_USERNAME']
+  # config.username = -> { Rails.application.credentials.dig(:solid_queue_monitor, :username) }
 
   # Set the password for HTTP Basic Authentication (only used if authentication is enabled)
   # config.password = 'password'
+  # config.password = ENV['SOLID_QUEUE_MONITOR_PASSWORD']
+  # config.password = -> { Rails.application.credentials.dig(:solid_queue_monitor, :password) }
 
   # Number of jobs to display per page
   # config.jobs_per_page = 25
diff --git a/lib/solid_queue_monitor.rb b/lib/solid_queue_monitor.rb
index ddc7b83..daf912b 100644
--- a/lib/solid_queue_monitor.rb
+++ b/lib/solid_queue_monitor.rb
@@ -6,8 +6,23 @@
 module SolidQueueMonitor
   class Error < StandardError; end
   class << self
-    attr_accessor :username, :password, :jobs_per_page, :authentication_enabled,
+    attr_writer :username, :password
+    attr_accessor :jobs_per_page, :authentication_enabled,
                   :auto_refresh_enabled, :auto_refresh_interval, :show_chart
+
+    def username
+      resolve_value(@username)
+    end
+
+    def password
+      resolve_value(@password)
+    end
+
+    private
+
+    def resolve_value(value)
+      value.respond_to?(:call) ? value.call : value
+    end
   end
 
   @username = 'admin'
diff --git a/lib/solid_queue_monitor/version.rb b/lib/solid_queue_monitor/version.rb
index 82420dd..c15a1a8 100644
--- a/lib/solid_queue_monitor/version.rb
+++ b/lib/solid_queue_monitor/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module SolidQueueMonitor
-  VERSION = '1.2.0'
+  VERSION = '1.2.1'
 end
diff --git a/spec/services/solid_queue_monitor/authentication_service_spec.rb b/spec/services/solid_queue_monitor/authentication_service_spec.rb
index cbb88cf..0d70020 100644
--- a/spec/services/solid_queue_monitor/authentication_service_spec.rb
+++ b/spec/services/solid_queue_monitor/authentication_service_spec.rb
@@ -37,6 +37,28 @@
         expect(described_class.authenticate('wrong', 'wrong')).to be false
       end
     end
+
+    context 'when credentials are configured with callables' do
+      before do
+        SolidQueueMonitor.authentication_enabled = true
+        SolidQueueMonitor.username = -> { 'lambda_user' }
+        SolidQueueMonitor.password = -> { 'lambda_pass' }
+      end
+
+      after do
+        SolidQueueMonitor.authentication_enabled = false
+        SolidQueueMonitor.username = 'admin'
+        SolidQueueMonitor.password = 'password'
+      end
+
+      it 'resolves callable values for authentication' do
+        expect(described_class.authenticate('lambda_user', 'lambda_pass')).to be true
+      end
+
+      it 'rejects incorrect credentials with callable values' do
+        expect(described_class.authenticate('wrong', 'wrong')).to be false
+      end
+    end
   end
 
   describe '.authentication_required?' do