Allow specifying the server version

README.md

@@ -50,6 +50,7 @@ module ModelContextProtocol
     def index
       server = ModelContextProtocol::Server.new(
         name: "my_server",
+        version: "1.0.0",
         tools: [SomeTool, AnotherTool],
         prompts: [MyPrompt],
         server_context: { user_id: current_user.id },

examples/stdio_server.rb

@@ -54,6 +54,7 @@ def template(args, server_context:)
 # Set up the server
 server = MCP::Server.new(
   name: "example_server",
+  version: "1.0.0",
   tools: [ExampleTool],
   prompts: [ExamplePrompt],
   resources: [

lib/model_context_protocol/server.rb

@@ -6,6 +6,8 @@
 
 module ModelContextProtocol
   class Server
+    DEFAULT_VERSION = "0.1.0"
+
     class RequestHandlerError < StandardError
       attr_reader :error_type
       attr_reader :original_error
@@ -20,10 +22,11 @@ def initialize(message, request, error_type: :internal_error, original_error: ni
 
     include Instrumentation
 
-    attr_accessor :name, :tools, :prompts, :resources, :server_context, :configuration, :capabilities
+    attr_accessor :name, :version, :tools, :prompts, :resources, :server_context, :configuration, :capabilities
 
     def initialize(
       name: "model_context_protocol",
+      version: DEFAULT_VERSION,
       tools: [],
       prompts: [],
       resources: [],
@@ -33,6 +36,7 @@ def initialize(
       capabilities: { prompts: {}, resources: {}, tools: {} }
     )
       @name = name
+      @version = version
       @tools = tools.to_h { |t| [t.name_value, t] }
       @prompts = prompts.to_h { |p| [p.name_value, p] }
       @resources = resources
@@ -153,7 +157,7 @@ def handle_request(request, method)
     def server_info
       @server_info ||= {
         name:,
-        version: ModelContextProtocol::VERSION,
+        version:,
       }
     end
 

test/model_context_protocol/server_test.rb

@@ -51,6 +51,7 @@ class ServerTest < ActiveSupport::TestCase
 
       @server = Server.new(
         name: @server_name,
+        version: "1.2.3",
         tools: [@tool, @tool_that_raises],
         prompts: [@prompt],
         resources: [@resource],
@@ -120,7 +121,7 @@ class ServerTest < ActiveSupport::TestCase
           },
           "serverInfo": {
             "name": @server_name,
-            "version": ModelContextProtocol::VERSION,
+            "version": "1.2.3",
           },
         },
       }
@@ -648,6 +649,18 @@ class ServerTest < ActiveSupport::TestCase
       assert_equal Configuration::DEFAULT_PROTOCOL_VERSION, response[:result][:protocolVersion]
     end
 
+    test "server uses default version when not configured" do
+      server = Server.new(name: "test_server")
+      request = {
+        jsonrpc: "2.0",
+        method: "initialize",
+        id: 1,
+      }
+
+      response = server.handle(request)
+      assert_equal Server::DEFAULT_VERSION, response[:result][:serverInfo][:version]
+    end
+
     test "#define_tool adds a tool to the server" do
       @server.define_tool(
         name: "defined_tool",