diff --git a/lib/mcp_client/auth.rb b/lib/mcp_client/auth.rb
index 8f4652f..fecfad2 100644
--- a/lib/mcp_client/auth.rb
+++ b/lib/mcp_client/auth.rb
@@ -86,21 +86,38 @@ def self.from_h(data)
 
     # OAuth client metadata for registration and authorization
     class ClientMetadata
-      attr_reader :redirect_uris, :token_endpoint_auth_method, :grant_types, :response_types, :scope
+      attr_reader :redirect_uris, :token_endpoint_auth_method, :grant_types, :response_types, :scope,
+                  :client_name, :client_uri, :logo_uri, :tos_uri, :policy_uri, :contacts
 
       # @param redirect_uris [Array<String>] List of valid redirect URIs
       # @param token_endpoint_auth_method [String] Authentication method for token endpoint
       # @param grant_types [Array<String>] Supported grant types
       # @param response_types [Array<String>] Supported response types
       # @param scope [String, nil] Requested scope
+      # @param client_name [String, nil] Human-readable client name
+      # @param client_uri [String, nil] URL of the client home page
+      # @param logo_uri [String, nil] URL of the client logo
+      # @param tos_uri [String, nil] URL of the client terms of service
+      # @param policy_uri [String, nil] URL of the client privacy policy
+      # @param contacts [Array<String>, nil] List of contact emails for the client
+      # rubocop:disable Metrics/ParameterLists
       def initialize(redirect_uris:, token_endpoint_auth_method: 'none',
                      grant_types: %w[authorization_code refresh_token],
-                     response_types: ['code'], scope: nil)
+                     response_types: ['code'], scope: nil,
+                     client_name: nil, client_uri: nil, logo_uri: nil,
+                     tos_uri: nil, policy_uri: nil, contacts: nil)
+        # rubocop:enable Metrics/ParameterLists
         @redirect_uris = redirect_uris
         @token_endpoint_auth_method = token_endpoint_auth_method
         @grant_types = grant_types
         @response_types = response_types
         @scope = scope
+        @client_name = client_name
+        @client_uri = client_uri
+        @logo_uri = logo_uri
+        @tos_uri = tos_uri
+        @policy_uri = policy_uri
+        @contacts = contacts
       end
 
       # Convert to hash for HTTP requests
@@ -111,7 +128,13 @@ def to_h
           token_endpoint_auth_method: @token_endpoint_auth_method,
           grant_types: @grant_types,
           response_types: @response_types,
-          scope: @scope
+          scope: @scope,
+          client_name: @client_name,
+          client_uri: @client_uri,
+          logo_uri: @logo_uri,
+          tos_uri: @tos_uri,
+          policy_uri: @policy_uri,
+          contacts: @contacts
         }.compact
       end
     end
@@ -180,7 +203,13 @@ def self.build_metadata_from_hash(metadata_data)
           grant_types: metadata_data[:grant_types] || metadata_data['grant_types'] ||
                        %w[authorization_code refresh_token],
           response_types: metadata_data[:response_types] || metadata_data['response_types'] || ['code'],
-          scope: metadata_data[:scope] || metadata_data['scope']
+          scope: metadata_data[:scope] || metadata_data['scope'],
+          client_name: metadata_data[:client_name] || metadata_data['client_name'],
+          client_uri: metadata_data[:client_uri] || metadata_data['client_uri'],
+          logo_uri: metadata_data[:logo_uri] || metadata_data['logo_uri'],
+          tos_uri: metadata_data[:tos_uri] || metadata_data['tos_uri'],
+          policy_uri: metadata_data[:policy_uri] || metadata_data['policy_uri'],
+          contacts: metadata_data[:contacts] || metadata_data['contacts']
         )
       end
 
diff --git a/lib/mcp_client/auth/oauth_provider.rb b/lib/mcp_client/auth/oauth_provider.rb
index 388e78a..1680e07 100644
--- a/lib/mcp_client/auth/oauth_provider.rb
+++ b/lib/mcp_client/auth/oauth_provider.rb
@@ -30,12 +30,16 @@ class OAuthProvider
       # @param scope [String, nil] OAuth scope
       # @param logger [Logger, nil] Optional logger
       # @param storage [Object, nil] Storage backend for tokens and client info
-      def initialize(server_url:, redirect_uri: 'http://localhost:8080/callback', scope: nil, logger: nil, storage: nil)
+      # @param client_metadata [Hash] Extra OIDC client metadata fields for DCR registration.
+      #   Supported keys: :client_name, :client_uri, :logo_uri, :tos_uri, :policy_uri, :contacts
+      def initialize(server_url:, redirect_uri: 'http://localhost:8080/callback', scope: nil, logger: nil, storage: nil,
+                     client_metadata: {})
         self.server_url = server_url
         self.redirect_uri = redirect_uri
         self.scope = scope
         self.logger = logger || Logger.new($stdout, level: Logger::WARN)
         self.storage = storage || MemoryStorage.new
+        @extra_client_metadata = client_metadata
         @http_client = create_http_client
       end
 
@@ -333,7 +337,8 @@ def register_client(server_metadata)
           token_endpoint_auth_method: 'none', # Public client
           grant_types: %w[authorization_code refresh_token],
           response_types: ['code'],
-          scope: scope
+          scope: scope,
+          **@extra_client_metadata
         )
 
         response = @http_client.post(server_metadata.registration_endpoint) do |req|
@@ -355,7 +360,13 @@ def register_client(server_metadata)
           token_endpoint_auth_method: data['token_endpoint_auth_method'] || 'none',
           grant_types: data['grant_types'] || %w[authorization_code refresh_token],
           response_types: data['response_types'] || ['code'],
-          scope: data['scope']
+          scope: data['scope'],
+          client_name: data['client_name'],
+          client_uri: data['client_uri'],
+          logo_uri: data['logo_uri'],
+          tos_uri: data['tos_uri'],
+          policy_uri: data['policy_uri'],
+          contacts: data['contacts']
         )
 
         # Warn if server changed redirect_uri
diff --git a/spec/lib/mcp_client/auth/oauth_provider_spec.rb b/spec/lib/mcp_client/auth/oauth_provider_spec.rb
index c1bdcfc..8a6a0d7 100644
--- a/spec/lib/mcp_client/auth/oauth_provider_spec.rb
+++ b/spec/lib/mcp_client/auth/oauth_provider_spec.rb
@@ -33,6 +33,21 @@
       provider = described_class.new(server_url: server_url)
       expect(provider.redirect_uri).to eq('http://localhost:8080/callback')
     end
+
+    it 'accepts extra client_metadata' do
+      provider = described_class.new(
+        server_url: server_url,
+        client_metadata: { client_name: 'My App', contacts: ['dev@example.com'] }
+      )
+      extra = provider.instance_variable_get(:@extra_client_metadata)
+      expect(extra).to eq(client_name: 'My App', contacts: ['dev@example.com'])
+    end
+
+    it 'defaults extra client_metadata to empty hash' do
+      provider = described_class.new(server_url: server_url)
+      extra = provider.instance_variable_get(:@extra_client_metadata)
+      expect(extra).to eq({})
+    end
   end
 
   describe 'OAuth discovery URL generation' do
@@ -276,4 +291,103 @@
       expect(logger).to have_received(:warn).with(expected_message)
     end
   end
+
+  describe '#register_client with extra client_metadata' do
+    let(:storage_instance) { MCPClient::Auth::OAuthProvider::MemoryStorage.new }
+    let(:logger) { instance_double('Logger') }
+    let(:extra_metadata) do
+      {
+        client_name: 'My MCP App',
+        client_uri: 'https://myapp.example.com',
+        logo_uri: 'https://myapp.example.com/logo.png',
+        tos_uri: 'https://myapp.example.com/tos',
+        policy_uri: 'https://myapp.example.com/privacy',
+        contacts: ['admin@myapp.example.com']
+      }
+    end
+    let(:provider) do
+      described_class.new(
+        server_url: 'https://mcp.example.com',
+        redirect_uri: redirect_uri,
+        scope: 'read',
+        logger: logger,
+        storage: storage_instance,
+        client_metadata: extra_metadata
+      )
+    end
+    let(:http_client) { double('Faraday::Connection') }
+    let(:server_metadata) do
+      instance_double(
+        'MCPClient::Auth::ServerMetadata',
+        registration_endpoint: 'https://auth.example.com/register'
+      )
+    end
+    let(:registration_response_body) do
+      {
+        'client_id' => 'new-client-id',
+        'client_name' => 'My MCP App',
+        'client_uri' => 'https://myapp.example.com',
+        'logo_uri' => 'https://myapp.example.com/logo.png',
+        'tos_uri' => 'https://myapp.example.com/tos',
+        'policy_uri' => 'https://myapp.example.com/privacy',
+        'contacts' => ['admin@myapp.example.com'],
+        'redirect_uris' => [redirect_uri]
+      }.to_json
+    end
+    let(:sent_bodies) { [] }
+
+    before do
+      allow(logger).to receive(:debug)
+      allow(logger).to receive(:warn)
+
+      provider.instance_variable_set(:@http_client, http_client)
+      response = instance_double('Faraday::Response', success?: true, status: 200, body: registration_response_body)
+
+      allow(http_client).to receive(:post) do |_url, &block|
+        request = Struct.new(:headers, :body).new({}, nil)
+        block.call(request)
+        sent_bodies << JSON.parse(request.body)
+        response
+      end
+    end
+
+    it 'sends extra metadata fields in DCR request' do
+      provider.send(:register_client, server_metadata)
+
+      body = sent_bodies.first
+      expect(body['client_name']).to eq('My MCP App')
+      expect(body['client_uri']).to eq('https://myapp.example.com')
+      expect(body['logo_uri']).to eq('https://myapp.example.com/logo.png')
+      expect(body['tos_uri']).to eq('https://myapp.example.com/tos')
+      expect(body['policy_uri']).to eq('https://myapp.example.com/privacy')
+      expect(body['contacts']).to eq(['admin@myapp.example.com'])
+    end
+
+    it 'parses extra metadata fields from server response' do
+      client_info = provider.send(:register_client, server_metadata)
+
+      expect(client_info.metadata.client_name).to eq('My MCP App')
+      expect(client_info.metadata.client_uri).to eq('https://myapp.example.com')
+      expect(client_info.metadata.logo_uri).to eq('https://myapp.example.com/logo.png')
+      expect(client_info.metadata.tos_uri).to eq('https://myapp.example.com/tos')
+      expect(client_info.metadata.policy_uri).to eq('https://myapp.example.com/privacy')
+      expect(client_info.metadata.contacts).to eq(['admin@myapp.example.com'])
+    end
+
+    it 'omits nil extra fields from DCR request' do
+      minimal_provider = described_class.new(
+        server_url: 'https://mcp.example.com',
+        redirect_uri: redirect_uri,
+        logger: logger,
+        storage: storage_instance
+      )
+      minimal_provider.instance_variable_set(:@http_client, http_client)
+
+      minimal_provider.send(:register_client, server_metadata)
+
+      body = sent_bodies.first
+      expect(body).not_to have_key('client_name')
+      expect(body).not_to have_key('contacts')
+    end
+  end
 end
diff --git a/spec/lib/mcp_client/auth_spec.rb b/spec/lib/mcp_client/auth_spec.rb
index 717578f..b5fd23d 100644
--- a/spec/lib/mcp_client/auth_spec.rb
+++ b/spec/lib/mcp_client/auth_spec.rb
@@ -105,6 +105,62 @@
           scope: 'read write'
         )
         expect(hash).not_to have_key(:client_id)
+        expect(hash).not_to have_key(:client_name)
+        expect(hash).not_to have_key(:logo_uri)
+      end
+
+      it 'includes extra OIDC fields when provided' do
+        metadata = described_class.new(
+          redirect_uris: ['http://localhost:8080/callback'],
+          client_name: 'My App',
+          client_uri: 'https://myapp.example.com',
+          logo_uri: 'https://myapp.example.com/logo.png',
+          tos_uri: 'https://myapp.example.com/tos',
+          policy_uri: 'https://myapp.example.com/privacy',
+          contacts: ['admin@myapp.example.com']
+        )
+        hash = metadata.to_h
+        expect(hash[:client_name]).to eq('My App')
+        expect(hash[:client_uri]).to eq('https://myapp.example.com')
+        expect(hash[:logo_uri]).to eq('https://myapp.example.com/logo.png')
+        expect(hash[:tos_uri]).to eq('https://myapp.example.com/tos')
+        expect(hash[:policy_uri]).to eq('https://myapp.example.com/privacy')
+        expect(hash[:contacts]).to eq(['admin@myapp.example.com'])
+      end
+    end
+
+    describe '.from_h (via ClientInfo.build_metadata_from_hash)' do
+      it 'round-trips extra fields through ClientInfo serialization' do
+        metadata = described_class.new(
+          redirect_uris: ['http://localhost:8080/callback'],
+          client_name: 'Test Client',
+          client_uri: 'https://test.example.com',
+          logo_uri: 'https://test.example.com/logo.png',
+          tos_uri: 'https://test.example.com/tos',
+          policy_uri: 'https://test.example.com/policy',
+          contacts: ['dev@test.example.com']
+        )
+        client_info = MCPClient::Auth::ClientInfo.new(client_id: 'cid', metadata: metadata)
+        restored = MCPClient::Auth::ClientInfo.from_h(client_info.to_h)
+
+        expect(restored.metadata.client_name).to eq('Test Client')
+        expect(restored.metadata.client_uri).to eq('https://test.example.com')
+        expect(restored.metadata.logo_uri).to eq('https://test.example.com/logo.png')
+        expect(restored.metadata.tos_uri).to eq('https://test.example.com/tos')
+        expect(restored.metadata.policy_uri).to eq('https://test.example.com/policy')
+        expect(restored.metadata.contacts).to eq(['dev@test.example.com'])
+      end
+
+      it 'round-trips extra fields with string keys' do
+        hash = {
+          'redirect_uris' => ['http://localhost/cb'],
+          'client_name' => 'String Key Client',
+          'contacts' => ['a@b.com']
+        }
+        restored = MCPClient::Auth::ClientInfo.build_metadata_from_hash(hash)
+
+        expect(restored.client_name).to eq('String Key Client')
+        expect(restored.contacts).to eq(['a@b.com'])
       end
     end
   end