diff --git a/Gemfile.lock b/Gemfile.lock
index f2fb273..1aa6cfc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    omniai (1.2.0)
+    omniai (1.2.1)
       event_stream_parser
       http
       zeitwerk
diff --git a/lib/omniai.rb b/lib/omniai.rb
index cb503bb..cc2323d 100644
--- a/lib/omniai.rb
+++ b/lib/omniai.rb
@@ -2,10 +2,12 @@
 
 require 'event_stream_parser'
 require 'http'
+require 'uri'
 require 'zeitwerk'
 
 loader = Zeitwerk::Loader.for_gem
 loader.inflector.inflect 'omniai' => 'OmniAI'
+loader.inflector.inflect 'url' => 'URL'
 loader.setup
 
 module OmniAI
diff --git a/lib/omniai/chat/content.rb b/lib/omniai/chat/content.rb
deleted file mode 100644
index fe28091..0000000
--- a/lib/omniai/chat/content.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-# frozen_string_literal: true
-
-module OmniAI
-  class Chat
-    # A file used for analysis.
-    class Content
-      attr_accessor :type, :value
-
-      # @param value [String]
-      # @param type [Symbol] :image / :video / :audio / :text
-      def initialize(value, type: :text)
-        @value = value
-        @type = type
-      end
-    end
-  end
-end
diff --git a/lib/omniai/chat/content/file.rb b/lib/omniai/chat/content/file.rb
new file mode 100644
index 0000000..a199f41
--- /dev/null
+++ b/lib/omniai/chat/content/file.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module OmniAI
+  class Chat
+    module Content
+      # A file that is either audio / image / video.
+      class File < Media
+        attr_accessor :io
+
+        # @param io [IO, Pathname, String]
+        # @param type [Symbol, String] :image, :video, :audio, "audio/flac", "image/jpeg", "video/mpeg", etc.
+        def initialize(io, type)
+          super(type)
+          @io = io
+        end
+
+        # @return [String]
+        def fetch!
+          case @io
+          when IO then @io.read
+          else ::File.binread(@io)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/omniai/chat/content/media.rb b/lib/omniai/chat/content/media.rb
new file mode 100644
index 0000000..f55de63
--- /dev/null
+++ b/lib/omniai/chat/content/media.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module OmniAI
+  class Chat
+    module Content
+      # An abstract class that represents audio / image / video and is used for both files and urls.
+      class Media
+        attr_accessor :type
+
+        # @param type [String] "audio/flac", "image/jpeg", "video/mpeg", etc.
+        def initialize(type)
+          @type = type
+        end
+
+        # @return [Boolean]
+        def text?
+          @type.match?(%r{^text/})
+        end
+
+        # @return [Boolean]
+        def audio?
+          @type.match?(%r{^audio/})
+        end
+
+        # @return [Boolean]
+        def image?
+          @type.match?(%r{^image/})
+        end
+
+        # @return [Boolean]
+        def video?
+          @type.match?(%r{^video/})
+        end
+
+        # @yield [io]
+        def fetch!(&)
+          raise NotImplementedError, "#{self.class}#fetch! undefined"
+        end
+
+        # e.g. "Hello" -> "SGVsbG8h"
+        #
+        # @return [String]
+        def data
+          Base64.strict_encode64(fetch!)
+        end
+
+        # e.g. "data:text/html;base64,..."
+        #
+        # @return [String]
+        def data_uri
+          "data:#{@type};base64,#{data}"
+        end
+      end
+    end
+  end
+end
diff --git a/lib/omniai/chat/content/text.rb b/lib/omniai/chat/content/text.rb
new file mode 100644
index 0000000..7300e6e
--- /dev/null
+++ b/lib/omniai/chat/content/text.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module OmniAI
+  class Chat
+    module Content
+      # Just some text.
+      class Text
+        attr_accessor :text
+
+        # @param text [text]
+        def initialize(text)
+          @text = text
+        end
+      end
+    end
+  end
+end
diff --git a/lib/omniai/chat/content/url.rb b/lib/omniai/chat/content/url.rb
new file mode 100644
index 0000000..9d694c6
--- /dev/null
+++ b/lib/omniai/chat/content/url.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+module OmniAI
+  class Chat
+    module Content
+      # A url that is either audio / image / video.
+      class URL < Media
+        attr_accessor :url, :type
+
+        class HTTPError < OmniAI::HTTPError; end
+
+        # @param url [URI, String]
+        # @param type [Symbol, String] "audio/flac", "image/jpeg", "video/mpeg", etc.
+        def initialize(url, type)
+          super(type)
+          @url = url
+        end
+
+        # @raise [HTTPError]
+        #
+        # @return [String]
+        def fetch!
+          response = request!
+          String(response.body)
+        end
+
+        private
+
+        # @raise [HTTPError]
+        #
+        # @return [HTTP::Response]
+        def request!
+          response = HTTP.get(@url)
+          raise HTTPError, response.flush unless response.status.success?
+
+          response
+        end
+      end
+    end
+  end
+end
diff --git a/lib/omniai/version.rb b/lib/omniai/version.rb
index 5f17a84..b13e443 100644
--- a/lib/omniai/version.rb
+++ b/lib/omniai/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module OmniAI
-  VERSION = '1.2.0'
+  VERSION = '1.2.1'
 end
diff --git a/spec/omniai/chat/content/file_spec.rb b/spec/omniai/chat/content/file_spec.rb
new file mode 100644
index 0000000..1d6565f
--- /dev/null
+++ b/spec/omniai/chat/content/file_spec.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+RSpec.describe OmniAI::Chat::Content::File do
+  subject(:file) { described_class.new(io, type) }
+
+  let(:io) do
+    Tempfile.new.tap do |tempfile|
+      tempfile.write('Hello!')
+      tempfile.rewind
+    end
+  end
+
+  let(:type) { 'text/plain' }
+
+  around do |example|
+    example.call
+  ensure
+    io.close
+    io.unlink
+  end
+
+  describe '#type' do
+    it { expect(file.type).to eq('text/plain') }
+  end
+
+  describe '#io' do
+    it { expect(file.io).to eq(io) }
+  end
+
+  describe '#fetch!' do
+    it { expect(file.fetch!).to eql('Hello!') }
+  end
+
+  describe '#data' do
+    it { expect(file.data).to eq('SGVsbG8h') }
+  end
+
+  describe '#data_uri' do
+    it { expect(file.data_uri).to eq('data:text/plain;base64,SGVsbG8h') }
+  end
+end
diff --git a/spec/omniai/chat/content/media_spec.rb b/spec/omniai/chat/content/media_spec.rb
new file mode 100644
index 0000000..0426e9c
--- /dev/null
+++ b/spec/omniai/chat/content/media_spec.rb
@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+RSpec.describe OmniAI::Chat::Content::Media do
+  subject(:media) { described_class.new(type) }
+
+  let(:type) { 'text/plain' }
+
+  describe '#type' do
+    it { expect(media.type).to eq('text/plain') }
+  end
+
+  describe '#fetch!' do
+    it { expect { media.fetch! }.to raise_error(NotImplementedError) }
+  end
+
+  describe '#text?' do
+    context 'when type is text/plain' do
+      let(:type) { 'text/plain' }
+
+      it { expect(media).to be_text }
+    end
+
+    context 'when type is application/pdf' do
+      let(:type) { 'application/pdf' }
+
+      it { expect(media).not_to be_text }
+    end
+  end
+
+  describe '#audio?' do
+    context 'when type is audio/flac' do
+      let(:type) { 'audio/flac' }
+
+      it { expect(media).to be_audio }
+    end
+
+    context 'when type is application/pdf' do
+      let(:type) { 'application/pdf' }
+
+      it { expect(media).not_to be_audio }
+    end
+  end
+
+  describe '#image?' do
+    context 'when type is image/jpeg' do
+      let(:type) { 'image/jpeg' }
+
+      it { expect(media).to be_image }
+    end
+
+    context 'when type is application/pdf' do
+      let(:type) { 'application/pdf' }
+
+      it { expect(media).not_to be_image }
+    end
+  end
+
+  describe '#video?' do
+    context 'when type is video/mpeg' do
+      let(:type) { 'video/mpeg' }
+
+      it { expect(media).to be_video }
+    end
+
+    context 'when type is application/pdf' do
+      let(:type) { 'application/pdf' }
+
+      it { expect(media).not_to be_video }
+    end
+  end
+end
diff --git a/spec/omniai/chat/content/text_spec.rb b/spec/omniai/chat/content/text_spec.rb
new file mode 100644
index 0000000..5ae73a9
--- /dev/null
+++ b/spec/omniai/chat/content/text_spec.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+RSpec.describe OmniAI::Chat::Content::Text do
+  subject(:text) { described_class.new('Hello!') }
+
+  describe '#text' do
+    it { expect(text.text).to eq('Hello!') }
+  end
+end
diff --git a/spec/omniai/chat/content/url_spec.rb b/spec/omniai/chat/content/url_spec.rb
new file mode 100644
index 0000000..33a8455
--- /dev/null
+++ b/spec/omniai/chat/content/url_spec.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+RSpec.describe OmniAI::Chat::Content::URL do
+  subject(:url) { described_class.new('https://localhost/greeting.txt', 'text/plain') }
+
+  describe '#fetch!' do
+    before do
+      stub_request(:get, 'https://localhost/greeting.txt')
+        .to_return(body: 'Hello!', status: 200)
+    end
+
+    it { expect(url.fetch!).to eql('Hello!') }
+  end
+
+  describe '#data' do
+    before do
+      stub_request(:get, 'https://localhost/greeting.txt')
+        .to_return(body: 'Hello!', status: 200)
+    end
+
+    it { expect(url.data).to eq('SGVsbG8h') }
+  end
+
+  describe '#data_uri' do
+    before do
+      stub_request(:get, 'https://localhost/greeting.txt')
+        .to_return(body: 'Hello!', status: 200)
+    end
+
+    it { expect(url.data_uri).to eq('data:text/plain;base64,SGVsbG8h') }
+  end
+end