diff --git a/lib/circuitbox.rb b/lib/circuitbox.rb
index da85aca..06cc7df 100644
--- a/lib/circuitbox.rb
+++ b/lib/circuitbox.rb
@@ -11,6 +11,28 @@ class Circuitbox
   extend Configuration
 
   class << self
+    # @overload circuit(service_name, options = {})
+    #   Returns a Circuitbox::CircuitBreaker for the given service_name
+    #
+    #   @param service_name [String, Symbol] Name of the service
+    #     Mixing Symbols/Strings for the same service (:test/'test') will result in
+    #     multiple circuits being created that point to the same service.
+    #   @param options [Hash] Options for the circuit (See Circuitbox::CircuitBreaker#initialize options)
+    #     Any configuration options should always be passed when calling this method.
+    #   @return [Circuitbox::CircuitBreaker] CircuitBreaker for the given service_name
+    #
+    # @overload circuit(service_name, options = {}, &block)
+    #   Runs the circuit with the given block
+    #   The circuit's run method is called with `exception` set to false
+    #
+    #   @param service_name [String, Symbol] Name of the service
+    #     Mixing Symbols/Strings for the same service (:test/'test') will result in
+    #     multiple circuits being created that point to the same service.
+    #   @param options [Hash] Options for the circuit (See Circuitbox::CircuitBreaker#initialize options)
+    #     Any configuration options should always be passed when calling this method.
+    #
+    #   @return [Object] The result of the block
+    #   @return [nil] If the circuit is open
     def circuit(service_name, options, &block)
       circuit = find_or_create_circuit_breaker(service_name, options)
 
diff --git a/lib/circuitbox/configuration.rb b/lib/circuitbox/configuration.rb
index c9de597..fa79850 100644
--- a/lib/circuitbox/configuration.rb
+++ b/lib/circuitbox/configuration.rb
@@ -19,16 +19,30 @@ def self.extended(base)
       end
     end
 
+    # Configure Circuitbox's defaults
+    # After configuring the cached circuits are cleared
+    #
+    # @yieldparam [Circuitbox::Configuration] Circuitbox configuration
+    #
     def configure
       yield self
       clear_cached_circuits!
       nil
     end
 
+    # Circuit store used by circuits that are not configured with a specific circuit store
+    # Defaults to Circuitbox::MemoryStore
+    #
+    # @return [Circuitbox::MemoryStore, Moneta] Circuit store
     def default_circuit_store
       @default_circuit_store ||= MemoryStore.new
     end
 
+    # Notifier used by circuits that are not configured with a specific notifier.
+    # If ActiveSupport::Notifications is defined it defaults to Circuitbox::Notifier::ActiveSupport
+    # Otherwise it defaults to Circuitbox::Notifier::Null
+    #
+    # @return [Circuitbox::Notifier::ActiveSupport, Circuitbox::Notifier::Null] Notifier
     def default_notifier
       @default_notifier ||= if defined?(ActiveSupport::Notifications)
                               Notifier::ActiveSupport.new