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diff --git a/railties/lib/rails/commands/credentials/USAGE b/railties/lib/rails/commands/credentials/USAGE
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+++ b/railties/lib/rails/commands/credentials/USAGE
@@ -0,0 +1,40 @@
+=== Storing Encrypted Credentials in Source Control
+
+The Rails `credentials` commands provide access to encrypted credentials,
+so you can safely store access tokens, database passwords, and the like
+safely inside the app without relying on a mess of ENVs.
+
+This also allows for atomic deploys: no need to coordinate key changes
+to get everything working as the keys are shipped with the code.
+
+=== Setup
+
+Applications after Rails 5.2 automatically have a basic credentials file generated
+that just contains the secret_key_base used by MessageVerifiers/MessageEncryptors, like the ones
+signing and encrypting cookies.
+
+For applications created prior to Rails 5.2, we'll automatically generate a new
+credentials file in `config/credentials.yml.enc` the first time you run `bin/rails credentials:edit`.
+If you didn't have a master key saved in `config/master.key`, that'll be created too.
+
+Don't lose this master key! Put it in a password manager your team can access.
+Should you lose it no one, including you, will be able to access any encrypted
+credentials.
+
+Don't commit the key! Add `config/master.key` to your source control's
+ignore file. If you use Git, Rails handles this for you.
+
+Rails also looks for the master key in `ENV["RAILS_MASTER_KEY"]`, if that's easier to manage.
+
+You could prepend that to your server's start command like this:
+
+   RAILS_MASTER_KEY="very-secret-and-secure" server.start
+
+=== Editing Credentials
+
+This will open a temporary file in `$EDITOR` with the decrypted contents to edit
+the encrypted credentials.
+
+When the temporary file is next saved the contents are encrypted and written to
+`config/credentials.yml.enc` while the file itself is destroyed to prevent credentials
+from leaking.
diff --git a/railties/lib/rails/commands/credentials/credentials_command.rb b/railties/lib/rails/commands/credentials/credentials_command.rb
new file mode 100644
index 0000000000..e5d3d01431
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+++ b/railties/lib/rails/commands/credentials/credentials_command.rb
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+# frozen_string_literal: true
+
+require "active_support"
+
+module Rails
+  module Command
+    class CredentialsCommand < Rails::Command::Base # :nodoc:
+      no_commands do
+        def help
+          say "Usage:\n  #{self.class.banner}"
+          say ""
+          say self.class.desc
+        end
+      end
+
+      def edit
+        require_application_and_environment!
+
+        ensure_editor_available || (return)
+        ensure_master_key_has_been_added
+        ensure_credentials_have_been_added
+
+        change_credentials_in_system_editor
+
+        say "New credentials encrypted and saved."
+      rescue Interrupt
+        say "Aborted changing credentials: nothing saved."
+      rescue ActiveSupport::EncryptedFile::MissingKeyError => error
+        say error.message
+      end
+
+      def show
+        require_application_and_environment!
+        say Rails.application.credentials.read.presence ||
+          "No credentials have been added yet. Use bin/rails credentials:edit to change that."
+      end
+
+      private
+        def ensure_editor_available
+          if ENV["EDITOR"].to_s.empty?
+            say "No $EDITOR to open credentials in. Assign one like this:"
+            say ""
+            say %(EDITOR="mate --wait" bin/rails credentials:edit)
+            say ""
+            say "For editors that fork and exit immediately, it's important to pass a wait flag,"
+            say "otherwise the credentials will be saved immediately with no chance to edit."
+
+            false
+          else
+            true
+          end
+        end
+
+        def ensure_master_key_has_been_added
+          master_key_generator.add_master_key_file
+          master_key_generator.ignore_master_key_file
+        end
+
+        def ensure_credentials_have_been_added
+          credentials_generator.add_credentials_file_silently
+        end
+
+        def change_credentials_in_system_editor
+          Rails.application.credentials.change do |tmp_path|
+            system("#{ENV["EDITOR"]} #{tmp_path}")
+          end
+        end
+
+
+        def master_key_generator
+          require "rails/generators"
+          require "rails/generators/rails/master_key/master_key_generator"
+
+          Rails::Generators::MasterKeyGenerator.new
+        end
+
+        def credentials_generator
+          require "rails/generators"
+          require "rails/generators/rails/credentials/credentials_generator"
+
+          Rails::Generators::CredentialsGenerator.new
+        end
+    end
+  end
+end