diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 2a0d4b4..c3d88f1 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -23,6 +23,8 @@ jobs:
           bundler-cache: true
       - name: Run rubocop
         run: bundle exec rubocop
+      - name: Run rbs + steep
+        run: bundle exec steep check
   spec:
     runs-on: ubuntu-latest
     strategy:
diff --git a/.rubocop.yml b/.rubocop.yml
index a9c7643..0fb4c43 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1327,6 +1327,8 @@ Metrics/AbcSize:
   # The ABC size is a calculated magnitude, so this number can be an Integer or
   # a Float.
   Max: 20
+  AllowedMethods:
+    - 'closest_node'
   Exclude:
     - 'tasks/*.rb'
 
@@ -1353,6 +1355,9 @@ Metrics/ClassLength:
 # Avoid complex methods.
 Metrics/CyclomaticComplexity:
   Max: 6
+  AllowedMethods:
+    - 'children_match_prefix'
+    - 'closest_node'
 
 Metrics/MethodLength:
   CountComments: false  # count full line comments?
diff --git a/Gemfile b/Gemfile
index a915cc3..e3648cc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,9 +12,11 @@ group :development do
   gem 'memory_profiler'
   gem 'pry'
   gem 'rake'
+  gem 'rbs'
   gem 'rspec'
   gem 'ruby-prof'
   gem 'stackprof'
+  gem 'steep'
   gem 'yard'
 end
 
diff --git a/Steepfile b/Steepfile
new file mode 100644
index 0000000..ca0e966
--- /dev/null
+++ b/Steepfile
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+# D = Steep::Diagnostic
+#
+target :lib do
+  signature 'sig'
+
+  check 'lib'
+  # check 'tasks'
+
+  # check 'Gemfile'
+  # check 'Guardfile'
+  # check 'Rakefile'
+  # check 'Steepfile'
+
+  # library 'rubyzip'
+  library 'yaml'
+  library 'securerandom'
+
+  # configure_code_diagnostics(D::Ruby.default)      # `default` diagnostics setting (applies by default)
+  # configure_code_diagnostics(D::Ruby.strict)       # `strict` diagnostics setting
+  # configure_code_diagnostics(D::Ruby.lenient)      # `lenient` diagnostics setting
+  # configure_code_diagnostics(D::Ruby.silent)       # `silent` diagnostics setting
+  # configure_code_diagnostics do |hash|             # You can setup everything yourself
+  #   hash[D::Ruby::NoMethod] = :information
+  # end
+end
+
+# target :test do
+#   signature 'sig', 'sig-private'
+#
+#   check 'test'
+#
+#   # library 'pathname'              # Standard libraries
+# end
diff --git a/lib/rambling/trie.rb b/lib/rambling/trie.rb
index 04c8fe2..e3b84a0 100644
--- a/lib/rambling/trie.rb
+++ b/lib/rambling/trie.rb
@@ -26,7 +26,7 @@ def create filepath = nil, reader = nil
           if filepath
             reader ||= readers.resolve filepath
             # noinspection RubyMismatchedArgumentType,RubyNilAnalysis
-            reader.each_word filepath do |word|
+            (reader || raise).each_word filepath do |word|
               container << word
             end
           end
@@ -48,7 +48,7 @@ def create filepath = nil, reader = nil
       #   discouraged. Only use the +.marshal+ format with trusted input.
       def load filepath, serializer = nil
         serializer ||= serializers.resolve filepath
-        root = serializer.load filepath
+        root = (serializer || raise).load filepath
         Rambling::Trie::Container.new root, compressor do |container|
           yield container if block_given?
         end
@@ -66,7 +66,7 @@ def load filepath, serializer = nil
       def dump trie, filepath, serializer = nil
         serializer ||= serializers.resolve filepath
         # noinspection RubyNilAnalysis
-        serializer.dump trie.root, filepath
+        (serializer || raise).dump trie.root, filepath
       end
 
       # Provides configuration properties for the +Rambling::Trie+ gem.
diff --git a/lib/rambling/trie/compressor.rb b/lib/rambling/trie/compressor.rb
index 1314f92..c76e7b4 100644
--- a/lib/rambling/trie/compressor.rb
+++ b/lib/rambling/trie/compressor.rb
@@ -5,9 +5,11 @@ module Trie
     # Responsible for the compression process of a trie data structure.
     class Compressor
       # Compresses a {Nodes::Node Node} from a trie data structure.
-      # @param [Nodes::Raw] node the node to compress.
+      # @param [Nodes::Node] node the node to compress.
       # @return [Nodes::Compressed] node the compressed version of the node.
       def compress node
+        return if node.nil?
+
         if node.compressible?
           compress_child_and_merge node
         else
diff --git a/lib/rambling/trie/configuration/provider_collection.rb b/lib/rambling/trie/configuration/provider_collection.rb
index 7e82743..df270df 100644
--- a/lib/rambling/trie/configuration/provider_collection.rb
+++ b/lib/rambling/trie/configuration/provider_collection.rb
@@ -104,7 +104,10 @@ def file_format filepath
         end
 
         def contains? provider
-          provider.nil? || (providers.any? && provider_instances.include?(provider))
+          return true if provider.nil?
+
+          p = (provider || raise)
+          providers.any? && provider_instances.include?(p)
         end
 
         alias_method :provider_instances, :values
diff --git a/lib/rambling/trie/container.rb b/lib/rambling/trie/container.rb
index b56edf4..b1dda0c 100644
--- a/lib/rambling/trie/container.rb
+++ b/lib/rambling/trie/container.rb
@@ -98,7 +98,7 @@ def scan word = ''
 
       # Returns all words within a string that match a word contained in the trie.
       # @param [String] phrase the string to look for matching words in.
-      # @return [Enumerator<String>] all the words in the given string that match a word in the trie.
+      # @return [Array<String>] all the words in the given string that match a word in the trie.
       # @yield [String] each word found in phrase.
       def words_within phrase
         words_within_root(phrase).to_a
@@ -201,16 +201,18 @@ def words_within_root phrase
         return enum_for :words_within_root, phrase unless block_given?
 
         chars = phrase.chars
+        # rubocop:disable Style/CommentedKeyword
         0.upto(chars.length - 1).each do |starting_index|
-          new_phrase = chars.slice starting_index..(chars.length - 1)
+          new_phrase = chars.slice starting_index..(chars.length - 1) # : Array[String]
           root.match_prefix new_phrase do |word|
             yield word
           end
-        end
+        end # : Enumerator[String, void]
+        # rubocop:enable Style/CommentedKeyword
       end
 
       def compress_root
-        compressor.compress root
+        compressor.compress root # : Nodes::Compressed
       end
 
       def char_symbols word
diff --git a/lib/rambling/trie/enumerable.rb b/lib/rambling/trie/enumerable.rb
index b3ca64f..7ffaee1 100644
--- a/lib/rambling/trie/enumerable.rb
+++ b/lib/rambling/trie/enumerable.rb
@@ -6,6 +6,8 @@ module Trie
     module Enumerable
       include ::Enumerable
 
+      EMPTY_ENUMERATOR = [].to_enum :each
+
       # Returns number of words contained in the trie
       # @see https://ruby-doc.org/core-2.7.0/Enumerable.html#method-i-count Enumerable#count
       alias_method :size, :count
diff --git a/lib/rambling/trie/nodes/compressed.rb b/lib/rambling/trie/nodes/compressed.rb
index 5c901c2..d9fcc8c 100644
--- a/lib/rambling/trie/nodes/compressed.rb
+++ b/lib/rambling/trie/nodes/compressed.rb
@@ -23,13 +23,13 @@ def compressed?
         private
 
         def partial_word_chars? chars
-          child = children_tree[chars.first.to_sym]
+          child = children_tree[(chars.first || raise).to_sym]
           return false unless child
 
           child_letter = child.letter.to_s
 
           if chars.size >= child_letter.size
-            letter = chars.slice!(0, child_letter.size).join
+            letter = (chars.slice!(0, child_letter.size) || raise).join
             return child.partial_word? chars if child_letter == letter
           end
 
@@ -39,7 +39,7 @@ def partial_word_chars? chars
         end
 
         def word_chars? chars
-          letter = chars.slice! 0
+          letter = chars.slice!(0) || raise
           letter_sym = letter.to_sym
 
           child = children_tree[letter_sym]
@@ -50,7 +50,7 @@ def word_chars? chars
 
             break if chars.empty?
 
-            letter << chars.slice!(0)
+            letter << (chars.slice!(0) || raise)
             letter_sym = letter.to_sym
           end
 
@@ -58,13 +58,13 @@ def word_chars? chars
         end
 
         def closest_node chars
-          child = children_tree[chars.first.to_sym]
+          child = children_tree[(chars.first || raise).to_sym]
           return missing unless child
 
           child_letter = child.letter.to_s
 
           if chars.size >= child_letter.size
-            letter = chars.slice!(0, child_letter.size).join
+            letter = (chars.slice!(0, child_letter.size) || raise).join
             return child.scan chars if child_letter == letter
           end
 
@@ -77,15 +77,15 @@ def closest_node chars
         def children_match_prefix chars
           return enum_for :children_match_prefix, chars unless block_given?
 
-          return if chars.empty?
+          return EMPTY_ENUMERATOR if chars.empty?
 
-          child = children_tree[chars.first.to_sym]
-          return unless child
+          child = children_tree[(chars.first || raise).to_sym]
+          return EMPTY_ENUMERATOR unless child
 
           child_letter = child.letter.to_s
-          letter = chars.slice!(0, child_letter.size).join
+          letter = (chars.slice!(0, child_letter.size) || raise).join
 
-          return unless child_letter == letter
+          return EMPTY_ENUMERATOR unless child_letter == letter
 
           child.match_prefix chars do |word|
             yield word
diff --git a/lib/rambling/trie/nodes/node.rb b/lib/rambling/trie/nodes/node.rb
index 4163e9d..d0a495c 100644
--- a/lib/rambling/trie/nodes/node.rb
+++ b/lib/rambling/trie/nodes/node.rb
@@ -52,6 +52,8 @@ def first_child
           # rubocop:disable Lint/UnreachableLoop
           children_tree.each_value { |child| return child }
           # rubocop:enable Lint/UnreachableLoop
+
+          nil
         end
 
         # Indicates if the current node is the root node.
@@ -106,7 +108,7 @@ def scan chars
         end
 
         # Returns all words that match a prefix of any length within chars.
-        # @param [String] chars the chars to base the prefix on.
+        # @param [Array[String]] chars the chars to base the prefix on.
         # @return [Enumerator<String>] all the words that match a prefix by chars.
         # @yield [String] each word found.
         def match_prefix chars
@@ -147,7 +149,7 @@ def key? letter
         # Delete a given letter and its corresponding {Node Node} from
         # this {Node Node}'s children tree.
         # @param [Symbol] letter the letter to delete from the node's children tree.
-        # @return [Node] the node corresponding to the deleted letter.
+        # @return [Node, nil] the node corresponding to the deleted letter.
         # @see https://ruby-doc.org/core-2.7.0/Hash.html#method-i-delete Hash#delete
         def delete letter
           children_tree.delete letter
diff --git a/lib/rambling/trie/nodes/raw.rb b/lib/rambling/trie/nodes/raw.rb
index 1a225db..1c3558d 100644
--- a/lib/rambling/trie/nodes/raw.rb
+++ b/lib/rambling/trie/nodes/raw.rb
@@ -7,7 +7,7 @@ module Nodes
       class Raw < Rambling::Trie::Nodes::Node
         # Adds a word to the current raw (uncompressed) trie node.
         # @param [Array<Symbol>] chars the char array to add to the trie.
-        # @return [Raw] the added/modified node based on the word added.
+        # @return [Node] the added/modified node based on the word added.
         # @note This method clears the contents of the chars variable.
         def add chars
           if chars.empty?
@@ -27,7 +27,7 @@ def compressed?
         private
 
         def add_to_children_tree chars
-          letter = chars.pop
+          letter = chars.pop || raise
           child = children_tree[letter] || new_node(letter)
           child.add chars
           child
@@ -40,7 +40,7 @@ def new_node letter
         end
 
         def partial_word_chars? chars = []
-          letter = chars.shift.to_sym
+          letter = (chars.shift || raise).to_sym
           child = children_tree[letter]
           return false unless child
 
@@ -48,7 +48,7 @@ def partial_word_chars? chars = []
         end
 
         def word_chars? chars = []
-          letter = chars.shift.to_sym
+          letter = (chars.shift || raise).to_sym
           child = children_tree[letter]
           return false unless child
 
@@ -56,7 +56,7 @@ def word_chars? chars = []
         end
 
         def closest_node chars
-          letter = chars.shift.to_sym
+          letter = (chars.shift || raise).to_sym
           child = children_tree[letter]
           return missing unless child
 
@@ -66,12 +66,12 @@ def closest_node chars
         def children_match_prefix chars
           return enum_for :children_match_prefix, chars unless block_given?
 
-          return if chars.empty?
+          return EMPTY_ENUMERATOR if chars.empty?
 
-          letter = chars.shift.to_sym
+          letter = (chars.shift || raise).to_sym
           child = children_tree[letter]
 
-          return unless child
+          return EMPTY_ENUMERATOR unless child
 
           child.match_prefix chars do |word|
             yield word
diff --git a/lib/rambling/trie/serializers/zip.rb b/lib/rambling/trie/serializers/zip.rb
index 809fbc9..b90ffb9 100644
--- a/lib/rambling/trie/serializers/zip.rb
+++ b/lib/rambling/trie/serializers/zip.rb
@@ -26,12 +26,14 @@ def load filepath
 
           ::Zip::File.open filepath do |zip|
             entry = zip.entries.first
-            return nil if entry.nil?
+            raise if entry.nil?
 
             entry_path = path entry.name
             entry.extract entry_path
 
             serializer = serializers.resolve entry.name
+            raise if serializer.nil?
+
             serializer.load entry_path
           end
         end
@@ -50,6 +52,9 @@ def dump contents, filepath
 
             entry_path = path filename
             serializer = serializers.resolve filename
+
+            raise if serializer.nil?
+
             serializer.dump contents, entry_path
 
             zip.add filename, entry_path
diff --git a/sig/lib/rambling/trie.rbs b/sig/lib/rambling/trie.rbs
new file mode 100644
index 0000000..9451f7b
--- /dev/null
+++ b/sig/lib/rambling/trie.rbs
@@ -0,0 +1,27 @@
+module Rambling
+  module Trie
+    VERSION: String
+
+    @properties: Configuration::Properties
+
+    def self.create: (?String?, ?Readers::Reader?) ?{ (Container) -> void } -> Container
+
+    def self.load: (String, ?Serializers::Serializer[Nodes::Node]?) ?{ (Container) -> void } -> Container
+
+    def self.dump: (Container, String, ?Serializers::Serializer[Nodes::Node]?) -> void
+
+    def self.config: ?{ (Configuration::Properties) -> void } -> Configuration::Properties
+
+    private
+
+    def self.properties: -> Configuration::Properties
+
+    def self.readers: -> Configuration::ProviderCollection[Readers::Reader]
+
+    def self.serializers: -> Configuration::ProviderCollection[Serializers::Serializer[Nodes::Node]]
+
+    def self.compressor: -> Compressor
+
+    def self.root_builder: -> ^() -> Nodes::Node
+  end
+end
diff --git a/sig/lib/rambling/trie/comparable.rbs b/sig/lib/rambling/trie/comparable.rbs
new file mode 100644
index 0000000..7b2a6e6
--- /dev/null
+++ b/sig/lib/rambling/trie/comparable.rbs
@@ -0,0 +1,17 @@
+module Rambling
+  module Trie
+    module Comparable
+      def ==: (Nodes::Node) -> bool
+
+      private
+
+      # abstract methods
+
+      def letter: -> Symbol
+
+      def terminal?: -> bool
+
+      def children_tree: -> Hash[Symbol, Nodes::Node]
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/compressible.rbs b/sig/lib/rambling/trie/compressible.rbs
new file mode 100644
index 0000000..774335c
--- /dev/null
+++ b/sig/lib/rambling/trie/compressible.rbs
@@ -0,0 +1,17 @@
+module Rambling
+  module Trie
+    module Compressible
+      def compressible?: -> bool
+
+      private
+
+      # abstract methods
+
+      def root?: -> bool
+
+      def terminal?: -> bool
+
+      def children_tree: -> Hash[Symbol, Nodes::Node]
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/compressor.rbs b/sig/lib/rambling/trie/compressor.rbs
new file mode 100644
index 0000000..96181b9
--- /dev/null
+++ b/sig/lib/rambling/trie/compressor.rbs
@@ -0,0 +1,19 @@
+module Rambling
+  module Trie
+    class Compressor
+      def compress: (Nodes::Node?) -> Nodes::Compressed?
+
+      private
+
+      def compress_child_and_merge: (Nodes::Node) -> Nodes::Compressed
+
+      def merge: (Nodes::Node, Nodes::Node?) -> Nodes::Compressed
+
+      def compress_children_and_copy: (Nodes::Node) -> Nodes::Compressed
+
+      def compress_children: (Hash[Symbol, Nodes::Node]) -> Hash[Symbol, Nodes::Node]
+
+      def new_compressed_node: (Symbol?, Nodes::Node?, Hash[Symbol, Nodes::Node], bool?) -> Nodes::Compressed
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/configuration/properties.rbs b/sig/lib/rambling/trie/configuration/properties.rbs
new file mode 100644
index 0000000..29e0808
--- /dev/null
+++ b/sig/lib/rambling/trie/configuration/properties.rbs
@@ -0,0 +1,28 @@
+module Rambling
+  module Trie
+    module Configuration
+      class Properties
+        attr_reader readers: ProviderCollection[Readers::Reader]
+        attr_reader serializers: ProviderCollection[Serializers::Serializer[Nodes::Node]]
+        attr_accessor compressor: Compressor
+        attr_accessor root_builder: ^() -> Nodes::Node
+        attr_accessor tmp_path: String
+
+        def initialize: -> void
+
+        def reset: -> void
+
+        private
+
+        attr_writer readers: ProviderCollection[Readers::Reader]
+        attr_writer serializers: ProviderCollection[Serializers::Serializer[Nodes::Node]]
+
+        def reset_readers: -> void
+
+        def default_reader_providers: -> Hash[Symbol, Readers::Reader]
+
+        def reset_serializers: -> void
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/configuration/provider_collection.rbs b/sig/lib/rambling/trie/configuration/provider_collection.rbs
new file mode 100644
index 0000000..8d8b497
--- /dev/null
+++ b/sig/lib/rambling/trie/configuration/provider_collection.rbs
@@ -0,0 +1,47 @@
+module Rambling
+  module Trie
+    module Configuration
+      class ProviderCollection[TProvider < _Nilable]
+        interface _Nilable
+          def nil?: -> bool
+        end
+
+        @providers: Hash[Symbol, TProvider]
+
+        attr_reader name: Symbol
+        attr_reader default: TProvider?
+
+        def initialize: (Symbol, Hash[Symbol, TProvider], ?TProvider?) -> void
+
+        def []: (Symbol) -> TProvider
+
+        def add: (Symbol, TProvider) -> TProvider
+
+        def default=: (TProvider?) -> TProvider?
+
+        def formats: -> Array[Symbol]
+
+        def providers: -> Hash[Symbol, TProvider]
+
+        def reset: -> void
+
+        def resolve: (String) -> TProvider?
+
+        private
+
+        attr_reader configured_default: TProvider?
+        attr_reader configured_providers: Hash[Symbol, TProvider]
+
+        def []=: (Symbol, TProvider) -> TProvider
+
+        def values: -> Array[TProvider]
+
+        def file_format: (String) -> Symbol
+
+        def contains?: (TProvider?) -> bool
+
+        alias provider_instances values
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/container.rbs b/sig/lib/rambling/trie/container.rbs
new file mode 100644
index 0000000..f0627f9
--- /dev/null
+++ b/sig/lib/rambling/trie/container.rbs
@@ -0,0 +1,69 @@
+module Rambling
+  module Trie
+    class Container
+      include ::Enumerable[String]
+
+      @compressor: Compressor
+
+      attr_reader root: Nodes::Node
+
+      def initialize: (Nodes::Node, Compressor) ?{ (Container) -> void } -> void
+
+      def add: (String) -> Nodes::Node
+
+      def concat: (Array[String]) -> Array[Nodes::Node]
+
+      def compress!: -> Container
+
+      def compress: -> Container
+
+      def each: { (String) -> void } -> (Enumerator[String, void] | Enumerable)
+
+      def partial_word?: (String) -> bool
+
+      def push: (*String) -> Array[Nodes::Node]
+
+      def word?: (String) -> bool
+
+      def scan: (String) -> Array[String]
+
+      def words_within: (String) -> Array[String]
+
+      def words_within?: (String) -> bool
+
+      def ==: (Container) -> bool
+
+      def []: (Symbol) -> Nodes::Node
+
+      def children: -> Array[Nodes::Node]
+
+      def children_tree: -> Hash[Symbol, Nodes::Node]
+
+      def compressed?: -> bool
+
+      def to_a: -> Array[String]
+
+      def key?: (Symbol) -> bool
+
+      def size: -> Numeric
+
+      alias include? word?
+      alias match? partial_word?
+      alias words? scan
+      alias << add
+      alias has_key? key?
+      alias has_letter? key?
+
+      private
+
+      attr_reader compressor: Compressor
+      attr_writer root: Nodes::Node
+
+      def words_within_root: (String) ?{ (String) -> void } -> Enumerator[String, void]
+
+      def compress_root: -> Nodes::Compressed
+
+      def char_symbols: (String) -> Array[Symbol]
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/enumerable.rbs b/sig/lib/rambling/trie/enumerable.rbs
new file mode 100644
index 0000000..efec895
--- /dev/null
+++ b/sig/lib/rambling/trie/enumerable.rbs
@@ -0,0 +1,23 @@
+module Rambling
+  module Trie
+    module Enumerable
+      include ::Enumerable[String]
+
+      EMPTY_ENUMERATOR: Enumerator[String, void]
+
+      alias size count
+
+      def each: { (String) -> void } -> (Enumerator[String, void] | Enumerable)
+
+      private
+
+      # abstract methods
+
+      def as_word: -> String
+
+      def terminal?: -> bool
+
+      def children_tree: -> Hash[Symbol, Nodes::Node]
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/inspectable.rbs b/sig/lib/rambling/trie/inspectable.rbs
new file mode 100644
index 0000000..600e2a2
--- /dev/null
+++ b/sig/lib/rambling/trie/inspectable.rbs
@@ -0,0 +1,27 @@
+module Rambling
+  module Trie
+    module Inspectable
+      def inspect: -> String
+
+      private
+
+      def class_name: -> String?
+
+      def attributes: -> String
+
+      def letter_inspect: -> String
+
+      def terminal_inspect: -> String
+
+      def children_inspect: -> String
+
+      # abstract methods
+
+      def letter: -> Symbol
+
+      def terminal: -> bool?
+
+      def children_tree: -> Hash[Symbol, Nodes::Node]
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/invalid_operation.rbs b/sig/lib/rambling/trie/invalid_operation.rbs
new file mode 100644
index 0000000..f35485b
--- /dev/null
+++ b/sig/lib/rambling/trie/invalid_operation.rbs
@@ -0,0 +1,7 @@
+module Rambling
+  module Trie
+    class InvalidOperation < RuntimeError
+      def initialize: (String? message) -> void
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/nodes/compressed.rbs b/sig/lib/rambling/trie/nodes/compressed.rbs
new file mode 100644
index 0000000..ef76a63
--- /dev/null
+++ b/sig/lib/rambling/trie/nodes/compressed.rbs
@@ -0,0 +1,21 @@
+module Rambling
+  module Trie
+    module Nodes
+      class Compressed < Node
+        def add: (Array[Symbol]) -> Node
+
+        def compressed?: -> bool
+
+        private
+
+        def partial_word_chars?: (Array[String]) -> bool
+
+        def word_chars?: (Array[String]) -> bool
+
+        def closest_node: (Array[String]) -> Node
+
+        def children_match_prefix: (Array[String]) { (String) -> void } -> Enumerator[String, void]
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/nodes/missing.rbs b/sig/lib/rambling/trie/nodes/missing.rbs
new file mode 100644
index 0000000..f84d9c4
--- /dev/null
+++ b/sig/lib/rambling/trie/nodes/missing.rbs
@@ -0,0 +1,9 @@
+module Rambling
+  module Trie
+    module Nodes
+      class Missing < Node
+        def initialize: -> void
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/sig/lib/rambling/trie/nodes/node.rbs b/sig/lib/rambling/trie/nodes/node.rbs
new file mode 100644
index 0000000..cab7efa
--- /dev/null
+++ b/sig/lib/rambling/trie/nodes/node.rbs
@@ -0,0 +1,69 @@
+module Rambling
+  module Trie
+    module Nodes
+      class Node
+        include Compressible
+        include Enumerable
+        include Comparable
+        include Stringifyable
+        include Inspectable
+
+        attr_reader letter: Symbol?
+        attr_accessor children_tree: Hash[Symbol, Node]
+        attr_accessor parent: Node?
+
+        def initialize: (?Symbol?, ?Node?, ?Hash[Symbol, Node]) -> void
+
+        def add: (Array[Symbol]) -> Node
+
+        def children: -> Array[Node]
+
+        def first_child: -> Node?
+
+        def match_prefix: (Array[String]) { (String) -> void } -> Enumerator[String, void]
+
+        def root?: -> bool
+
+        def scan: (Array[String]) -> Node
+
+        def terminal?: -> bool
+
+        def terminal!: -> Node
+
+        def letter=: (String | Symbol?) -> Symbol?
+
+        def compressed?: -> bool
+
+        def partial_word?: (Array[String]) -> bool
+
+        def word?: (Array[String]) -> bool
+
+        def []: (Symbol) -> Node
+
+        def []=: (Symbol, Node) -> Node
+
+        def key?: (Symbol) -> bool
+
+        def delete: (Symbol) -> Node?
+
+        alias has_key? key?
+
+        private
+
+        def missing: -> Node
+
+        attr_accessor terminal: bool?
+
+        # abstract methods
+
+        def partial_word_chars?: (Array[String]) -> bool
+
+        def word_chars?: (Array[String]) -> bool
+
+        def closest_node: (Array[String]) -> Node
+
+        def children_match_prefix: (Array[String]) { (String) -> void } -> Enumerator[String, void]
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/nodes/raw.rbs b/sig/lib/rambling/trie/nodes/raw.rbs
new file mode 100644
index 0000000..a7440f4
--- /dev/null
+++ b/sig/lib/rambling/trie/nodes/raw.rbs
@@ -0,0 +1,25 @@
+module Rambling
+  module Trie
+    module Nodes
+      class Raw < Node
+        def add: (Array[Symbol]) -> Node
+
+        def compressed?: -> bool
+
+        private
+
+        def add_to_children_tree: (Array[Symbol]) -> Node
+
+        def new_node: (Symbol) -> Node
+
+        def partial_word_chars?: (Array[String]) -> bool
+
+        def word_chars?: (Array[String]) -> bool
+
+        def closest_node: (Array[String]) -> Node
+
+        def children_match_prefix: (Array[String]) { (String) -> void } -> Enumerator[String, void]
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/readers/plain_text.rbs b/sig/lib/rambling/trie/readers/plain_text.rbs
new file mode 100644
index 0000000..4653dcc
--- /dev/null
+++ b/sig/lib/rambling/trie/readers/plain_text.rbs
@@ -0,0 +1,9 @@
+module Rambling
+  module Trie
+    module Readers
+      class PlainText < Reader
+        def each_word: (String) { (String?) -> void } -> (Enumerator[String?, void] | PlainText)
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/sig/lib/rambling/trie/readers/reader.rbs b/sig/lib/rambling/trie/readers/reader.rbs
new file mode 100644
index 0000000..6e0e791
--- /dev/null
+++ b/sig/lib/rambling/trie/readers/reader.rbs
@@ -0,0 +1,9 @@
+module Rambling
+  module Trie
+    module Readers
+      class Reader
+        def each_word: (String) { (String) -> void } -> (Enumerator[String, void] | Reader)
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/serializers/file.rbs b/sig/lib/rambling/trie/serializers/file.rbs
new file mode 100644
index 0000000..04a2caf
--- /dev/null
+++ b/sig/lib/rambling/trie/serializers/file.rbs
@@ -0,0 +1,8 @@
+module Rambling
+  module Trie
+    module Serializers
+      class File < Serializer[String]
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/serializers/marshal.rbs b/sig/lib/rambling/trie/serializers/marshal.rbs
new file mode 100644
index 0000000..6f9e5b3
--- /dev/null
+++ b/sig/lib/rambling/trie/serializers/marshal.rbs
@@ -0,0 +1,13 @@
+module Rambling
+  module Trie
+    module Serializers
+      class Marshal < Serializer[Nodes::Node]
+        @serializer: Serializer[String]
+
+        private
+
+        attr_reader serializer: Serializer[String]
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/serializers/serializer.rbs b/sig/lib/rambling/trie/serializers/serializer.rbs
new file mode 100644
index 0000000..f05100b
--- /dev/null
+++ b/sig/lib/rambling/trie/serializers/serializer.rbs
@@ -0,0 +1,10 @@
+module Rambling
+  module Trie
+    module Serializers
+      class Serializer[TContents]
+        def load: (String) -> TContents
+        def dump: (TContents, String) -> Numeric
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/serializers/yaml.rbs b/sig/lib/rambling/trie/serializers/yaml.rbs
new file mode 100644
index 0000000..a647977
--- /dev/null
+++ b/sig/lib/rambling/trie/serializers/yaml.rbs
@@ -0,0 +1,13 @@
+module Rambling
+  module Trie
+    module Serializers
+      class Yaml < Serializer[Nodes::Node]
+        @serializer: Serializer[String]
+
+        private
+
+        attr_reader serializer: Serializer[String]
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/serializers/zip.rbs b/sig/lib/rambling/trie/serializers/zip.rbs
new file mode 100644
index 0000000..083d0da
--- /dev/null
+++ b/sig/lib/rambling/trie/serializers/zip.rbs
@@ -0,0 +1,21 @@
+module Rambling
+  module Trie
+    module Serializers
+      class Zip < Serializer[Nodes::Node]
+        @properties: Configuration::Properties
+
+        def initialize: (Configuration::Properties) -> void
+
+        private
+
+        attr_reader properties: Configuration::Properties
+
+        def serializers: -> Configuration::ProviderCollection[Serializer[Nodes::Node]]
+
+        def tmp_path: -> String
+
+        def path: (String) -> String
+      end
+    end
+  end
+end
diff --git a/sig/lib/rambling/trie/stringifyable.rbs b/sig/lib/rambling/trie/stringifyable.rbs
new file mode 100644
index 0000000..e012c9a
--- /dev/null
+++ b/sig/lib/rambling/trie/stringifyable.rbs
@@ -0,0 +1,21 @@
+module Rambling
+  module Trie
+    module Stringifyable
+      def as_word: -> String
+
+      def to_s: -> String
+
+      private
+
+      # abstract methods
+
+      def letter: -> Symbol
+
+      def terminal?: -> bool
+
+      def parent: -> Nodes::Node?
+
+      def children_tree: -> Hash[Symbol, Nodes::Node]
+    end
+  end
+end
diff --git a/sig/lib/zip/entry.rbs b/sig/lib/zip/entry.rbs
new file mode 100644
index 0000000..21f798c
--- /dev/null
+++ b/sig/lib/zip/entry.rbs
@@ -0,0 +1,11 @@
+module Zip
+  class Entry
+    include Enumerable[Entry]
+
+    def name: -> String
+
+    def extract: (String) -> void
+
+    def each: ?{ (Entry) -> void } -> (Enumerator[Entry, void])
+  end
+end
\ No newline at end of file
diff --git a/sig/lib/zip/file.rbs b/sig/lib/zip/file.rbs
new file mode 100644
index 0000000..bd38cfa
--- /dev/null
+++ b/sig/lib/zip/file.rbs
@@ -0,0 +1,11 @@
+module Zip
+  class File
+    CREATE: bool
+
+    def self.open: [TContent] (String, ?bool?) { (File) -> TContent } -> TContent
+
+    def entries: -> Array[Entry]
+
+    def add: (String, String) -> void
+  end
+end
\ No newline at end of file