feat(mcp): export initialized result in client session

mcp/client.go

@@ -163,6 +163,8 @@ type ClientSession struct {
 	mcpConn          Connection
 }
 
+func (cs *ClientSession) InitializeResult() *InitializeResult { return cs.initializeResult }
+
 func (cs *ClientSession) setConn(c Connection) {
 	cs.mcpConn = c
 }

mcp/protocol.go

@@ -324,7 +324,7 @@ type InitializeResult struct {
 	// This property is reserved by the protocol to allow clients and servers to
 	// attach additional metadata to their responses.
 	Meta         `json:"_meta,omitempty"`
-	Capabilities *serverCapabilities `json:"capabilities"`
+	Capabilities *ServerCapabilities `json:"capabilities"`
 	// Instructions describing how to use the server and its features.
 	//
 	// This can be used by clients to improve the LLM's understanding of available
@@ -925,19 +925,19 @@ type Implementation struct {
 }
 
 // Present if the server supports argument autocompletion suggestions.
-type completionCapabilities struct{}
+type CompletionCapabilities struct{}
 
 // Present if the server supports sending log messages to the client.
-type loggingCapabilities struct{}
+type LoggingCapabilities struct{}
 
 // Present if the server offers any prompt templates.
-type promptCapabilities struct {
+type PromptCapabilities struct {
 	// Whether this server supports notifications for changes to the prompt list.
 	ListChanged bool `json:"listChanged,omitempty"`
 }
 
 // Present if the server offers any resources to read.
-type resourceCapabilities struct {
+type ResourceCapabilities struct {
 	// Whether this server supports notifications for changes to the resource list.
 	ListChanged bool `json:"listChanged,omitempty"`
 	// Whether this server supports subscribing to resource updates.
@@ -947,23 +947,23 @@ type resourceCapabilities struct {
 // Capabilities that a server may support. Known capabilities are defined here,
 // in this schema, but this is not a closed set: any server can define its own,
 // additional capabilities.
-type serverCapabilities struct {
+type ServerCapabilities struct {
 	// Present if the server supports argument autocompletion suggestions.
-	Completions *completionCapabilities `json:"completions,omitempty"`
+	Completions *CompletionCapabilities `json:"completions,omitempty"`
 	// Experimental, non-standard capabilities that the server supports.
 	Experimental map[string]struct{} `json:"experimental,omitempty"`
 	// Present if the server supports sending log messages to the client.
-	Logging *loggingCapabilities `json:"logging,omitempty"`
+	Logging *LoggingCapabilities `json:"logging,omitempty"`
 	// Present if the server offers any prompt templates.
-	Prompts *promptCapabilities `json:"prompts,omitempty"`
+	Prompts *PromptCapabilities `json:"prompts,omitempty"`
 	// Present if the server offers any resources to read.
-	Resources *resourceCapabilities `json:"resources,omitempty"`
+	Resources *ResourceCapabilities `json:"resources,omitempty"`
 	// Present if the server offers any tools to call.
-	Tools *toolCapabilities `json:"tools,omitempty"`
+	Tools *ToolCapabilities `json:"tools,omitempty"`
 }
 
 // Present if the server offers any tools to call.
-type toolCapabilities struct {
+type ToolCapabilities struct {
 	// Whether this server supports notifications for changes to the tool list.
 	ListChanged bool `json:"listChanged,omitempty"`
 }

mcp/server.go

@@ -233,23 +233,23 @@ func (s *Server) RemoveResourceTemplates(uriTemplates ...string) {
 		func() bool { return s.resourceTemplates.remove(uriTemplates...) })
 }
 
-func (s *Server) capabilities() *serverCapabilities {
+func (s *Server) capabilities() *ServerCapabilities {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	caps := &serverCapabilities{
+	caps := &ServerCapabilities{
 		// TODO(samthanawalla): check for completionHandler before advertising capability.
-		Completions: &completionCapabilities{},
-		Logging:     &loggingCapabilities{},
+		Completions: &CompletionCapabilities{},
+		Logging:     &LoggingCapabilities{},
 	}
 	if s.opts.HasTools || s.tools.len() > 0 {
-		caps.Tools = &toolCapabilities{ListChanged: true}
+		caps.Tools = &ToolCapabilities{ListChanged: true}
 	}
 	if s.opts.HasPrompts || s.prompts.len() > 0 {
-		caps.Prompts = &promptCapabilities{ListChanged: true}
+		caps.Prompts = &PromptCapabilities{ListChanged: true}
 	}
 	if s.opts.HasResources || s.resources.len() > 0 || s.resourceTemplates.len() > 0 {
-		caps.Resources = &resourceCapabilities{ListChanged: true}
+		caps.Resources = &ResourceCapabilities{ListChanged: true}
 		if s.opts.SubscribeHandler != nil {
 			caps.Resources.Subscribe = true
 		}

mcp/server_test.go

@@ -236,47 +236,47 @@ func TestServerCapabilities(t *testing.T) {
 		name             string
 		configureServer  func(s *Server)
 		serverOpts       ServerOptions
-		wantCapabilities *serverCapabilities
+		wantCapabilities *ServerCapabilities
 	}{
 		{
 			name:            "No capabilities",
 			configureServer: func(s *Server) {},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
 			},
 		},
 		{
 			name: "With prompts",
 			configureServer: func(s *Server) {
 				s.AddPrompt(&Prompt{Name: "p"}, nil)
 			},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
-				Prompts:     &promptCapabilities{ListChanged: true},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
+				Prompts:     &PromptCapabilities{ListChanged: true},
 			},
 		},
 		{
 			name: "With resources",
 			configureServer: func(s *Server) {
 				s.AddResource(&Resource{URI: "file:///r"}, nil)
 			},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
-				Resources:   &resourceCapabilities{ListChanged: true},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
+				Resources:   &ResourceCapabilities{ListChanged: true},
 			},
 		},
 		{
 			name: "With resource templates",
 			configureServer: func(s *Server) {
 				s.AddResourceTemplate(&ResourceTemplate{URITemplate: "file:///rt"}, nil)
 			},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
-				Resources:   &resourceCapabilities{ListChanged: true},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
+				Resources:   &ResourceCapabilities{ListChanged: true},
 			},
 		},
 		{
@@ -292,21 +292,21 @@ func TestServerCapabilities(t *testing.T) {
 					return nil
 				},
 			},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
-				Resources:   &resourceCapabilities{ListChanged: true, Subscribe: true},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
+				Resources:   &ResourceCapabilities{ListChanged: true, Subscribe: true},
 			},
 		},
 		{
 			name: "With tools",
 			configureServer: func(s *Server) {
 				s.AddTool(tool, nil)
 			},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
-				Tools:       &toolCapabilities{ListChanged: true},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
+				Tools:       &ToolCapabilities{ListChanged: true},
 			},
 		},
 		{
@@ -325,12 +325,12 @@ func TestServerCapabilities(t *testing.T) {
 					return nil
 				},
 			},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
-				Prompts:     &promptCapabilities{ListChanged: true},
-				Resources:   &resourceCapabilities{ListChanged: true, Subscribe: true},
-				Tools:       &toolCapabilities{ListChanged: true},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
+				Prompts:     &PromptCapabilities{ListChanged: true},
+				Resources:   &ResourceCapabilities{ListChanged: true, Subscribe: true},
+				Tools:       &ToolCapabilities{ListChanged: true},
 			},
 		},
 		{
@@ -341,12 +341,12 @@ func TestServerCapabilities(t *testing.T) {
 				HasResources: true,
 				HasTools:     true,
 			},
-			wantCapabilities: &serverCapabilities{
-				Completions: &completionCapabilities{},
-				Logging:     &loggingCapabilities{},
-				Prompts:     &promptCapabilities{ListChanged: true},
-				Resources:   &resourceCapabilities{ListChanged: true},
-				Tools:       &toolCapabilities{ListChanged: true},
+			wantCapabilities: &ServerCapabilities{
+				Completions: &CompletionCapabilities{},
+				Logging:     &LoggingCapabilities{},
+				Prompts:     &PromptCapabilities{ListChanged: true},
+				Resources:   &ResourceCapabilities{ListChanged: true},
+				Tools:       &ToolCapabilities{ListChanged: true},
 			},
 		},
 	}

mcp/streamable_test.go

@@ -313,10 +313,10 @@ func TestStreamableServerTransport(t *testing.T) {
 	// Predefined steps, to avoid repetition below.
 	initReq := req(1, methodInitialize, &InitializeParams{})
 	initResp := resp(1, &InitializeResult{
-		Capabilities: &serverCapabilities{
-			Completions: &completionCapabilities{},
-			Logging:     &loggingCapabilities{},
-			Tools:       &toolCapabilities{ListChanged: true},
+		Capabilities: &ServerCapabilities{
+			Completions: &CompletionCapabilities{},
+			Logging:     &LoggingCapabilities{},
+			Tools:       &ToolCapabilities{ListChanged: true},
 		},
 		ProtocolVersion: latestProtocolVersion,
 		ServerInfo:      &Implementation{Name: "testServer", Version: "v1.0.0"},
@@ -731,10 +731,10 @@ func TestStreamableClientTransportApplicationJSON(t *testing.T) {
 		}
 	}
 	initResult := &InitializeResult{
-		Capabilities: &serverCapabilities{
-			Completions: &completionCapabilities{},
-			Logging:     &loggingCapabilities{},
-			Tools:       &toolCapabilities{ListChanged: true},
+		Capabilities: &ServerCapabilities{
+			Completions: &CompletionCapabilities{},
+			Logging:     &LoggingCapabilities{},
+			Tools:       &ToolCapabilities{ListChanged: true},
 		},
 		ProtocolVersion: latestProtocolVersion,
 		ServerInfo:      &Implementation{Name: "testServer", Version: "v1.0.0"},