diff --git a/.gitignore b/.gitignore
index 9106b2a..35706a9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@
 /pkg/
 /spec/reports/
 /tmp/
+/.gem_rbs_collection
diff --git a/Steepfile b/Steepfile
new file mode 100644
index 0000000..b49afc6
--- /dev/null
+++ b/Steepfile
@@ -0,0 +1,29 @@
+# D = Steep::Diagnostic
+#
+# target :lib do
+#   signature "sig"
+#
+#   check "lib"                       # Directory name
+#   check "Gemfile"                   # File name
+#   check "app/models/**/*.rb"        # Glob
+#   # ignore "lib/templates/*.rb"
+#
+#   # library "pathname"              # Standard libraries
+#   # library "strong_json"           # Gems
+#
+#   # 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/rbs/inline/ast.rb b/lib/rbs/inline/ast.rb
new file mode 100644
index 0000000..73d4715
--- /dev/null
+++ b/lib/rbs/inline/ast.rb
@@ -0,0 +1,36 @@
+module RBS
+  module Inline
+    module AST
+      module Member
+        class RubyDef
+        end
+
+        class RubyAlias
+        end
+
+        class RubyMixin
+        end
+
+        class RubyAttr
+        end
+
+        class RBSDef
+        end
+
+        class RBSAlias
+        end
+
+        class RBSAttr
+        end
+      end
+
+      module Declaration
+        class ModuleDecl
+        end
+
+        class ClassDecl
+        end
+      end
+    end
+  end
+end
diff --git a/rbs_collection.lock.yaml b/rbs_collection.lock.yaml
new file mode 100644
index 0000000..d106958
--- /dev/null
+++ b/rbs_collection.lock.yaml
@@ -0,0 +1,64 @@
+---
+path: ".gem_rbs_collection"
+gems:
+- name: abbrev
+  version: '0'
+  source:
+    type: stdlib
+- name: fileutils
+  version: '0'
+  source:
+    type: stdlib
+- name: json
+  version: '0'
+  source:
+    type: stdlib
+- name: logger
+  version: '0'
+  source:
+    type: stdlib
+- name: minitest
+  version: '0'
+  source:
+    type: stdlib
+- name: monitor
+  version: '0'
+  source:
+    type: stdlib
+- name: mutex_m
+  version: '0'
+  source:
+    type: stdlib
+- name: optparse
+  version: '0'
+  source:
+    type: stdlib
+- name: pathname
+  version: '0'
+  source:
+    type: stdlib
+- name: prism
+  version: 0.24.0
+  source:
+    type: rubygems
+- name: rake
+  version: '13.0'
+  source:
+    type: git
+    name: ruby/gem_rbs_collection
+    revision: e047afdf7e470acf0d0cdff31bd9c3123be3ea39
+    remote: https://github.com/ruby/gem_rbs_collection.git
+    repo_dir: gems
+- name: rbs
+  version: 3.4.4
+  source:
+    type: rubygems
+- name: rdoc
+  version: '0'
+  source:
+    type: stdlib
+- name: tsort
+  version: '0'
+  source:
+    type: stdlib
+gemfile_lock_path: Gemfile.lock
diff --git a/rbs_collection.yaml b/rbs_collection.yaml
new file mode 100644
index 0000000..66e30ec
--- /dev/null
+++ b/rbs_collection.yaml
@@ -0,0 +1,19 @@
+# Download sources
+sources:
+  - type: git
+    name: ruby/gem_rbs_collection
+    remote: https://github.com/ruby/gem_rbs_collection.git
+    revision: main
+    repo_dir: gems
+
+# You can specify local directories as sources also.
+# - type: local
+#   path: path/to/your/local/repository
+
+# A directory to install the downloaded RBSs
+path: .gem_rbs_collection
+
+# gems:
+#   # If you want to avoid installing rbs files for gems, you can specify them here.
+#   - name: GEM_NAME
+#     ignore: true
diff --git a/sig/rbs/inline/ast.rbs b/sig/rbs/inline/ast.rbs
new file mode 100644
index 0000000..adf45bd
--- /dev/null
+++ b/sig/rbs/inline/ast.rbs
@@ -0,0 +1,12 @@
+module RBS
+  module Inline
+    module AST
+      module Member
+        type t = MethodDefinition
+      end
+
+      module Declaration
+      end
+    end
+  end
+end
diff --git a/yard-samples/hello.rb b/yard-samples/hello.rb
new file mode 100644
index 0000000..a23b493
--- /dev/null
+++ b/yard-samples/hello.rb
@@ -0,0 +1,6 @@
+require "prism"
+
+ast = Prism.parse_file("yard-samples/sample1.rb")
+
+pp ast.value
+pp ast.comments
diff --git a/yard-samples/sample1.rb b/yard-samples/sample1.rb
new file mode 100644
index 0000000..4dc7acc
--- /dev/null
+++ b/yard-samples/sample1.rb
@@ -0,0 +1,26 @@
+module Foo
+  # This is `Foo#foo` method
+  #
+  # @param i [Integer] Size of something
+  # @param j [Symbol,Integer] Something doing meaningful
+  # @return [String?] Returns a string or nil
+  #
+  #
+  # @rbs.method (Integer, String) -> void
+  #           | [A] () { () [self: String] -> A } -> A?
+  #
+  def foo(i, j)
+
+  end
+
+  # @rbs.inline
+  #   attr_reader hoge: String
+  #   attr_reader name: String?
+  def hoge
+
+  end
+
+  class Foo
+    # @rbs.inline include Foo[String]
+  end
+end