Refactor client to remove circular dependency

Move capability discovery from Client to StdioSession to break the circular
dependency where session.GetClient().AddToMCPServerWithSession(session) was
called. This cleaner design separates concerns and makes the code more
maintainable.

Author: dgellow

internal/client/client.go

@@ -134,83 +134,6 @@ func DefaultTransportCreator(conf *config.MCPClientConfig) (MCPClientInterface,
 	return nil, errors.New("invalid client type: must have either command or url")
 }
 
-// AddToMCPServer connects the client to an MCP server
-func (c *Client) AddToMCPServer(ctx context.Context, clientInfo mcp.Implementation, mcpServer *server.MCPServer) error {
-	return c.AddToMCPServerWithTokenCheck(ctx, clientInfo, mcpServer, "", false, nil, "", "", nil)
-}
-
-// AddToMCPServerWithTokenCheck connects the client to an MCP server with optional token checking
-func (c *Client) AddToMCPServerWithTokenCheck(
-	ctx context.Context,
-	clientInfo mcp.Implementation,
-	mcpServer *server.MCPServer,
-	userEmail string,
-	requiresToken bool,
-	tokenStore storage.UserTokenStore,
-	serverName string,
-	setupBaseURL string,
-	tokenSetup *config.TokenSetupConfig,
-) error {
-	return c.AddToMCPServerWithSession(ctx, clientInfo, mcpServer, userEmail, requiresToken, tokenStore, serverName, setupBaseURL, tokenSetup, nil)
-}
-
-// AddToMCPServerWithSession connects the client to an MCP server with optional session-specific tools
-func (c *Client) AddToMCPServerWithSession(
-	ctx context.Context,
-	clientInfo mcp.Implementation,
-	mcpServer *server.MCPServer,
-	userEmail string,
-	requiresToken bool,
-	tokenStore storage.UserTokenStore,
-	serverName string,
-	setupBaseURL string,
-	tokenSetup *config.TokenSetupConfig,
-	session server.ClientSession,
-) error {
-	if c.needManualStart {
-		err := c.client.Start(ctx)
-		if err != nil {
-			return err
-		}
-	}
-	initRequest := mcp.InitializeRequest{}
-	initRequest.Params.ProtocolVersion = mcp.LATEST_PROTOCOL_VERSION
-	initRequest.Params.ClientInfo = clientInfo
-	initRequest.Params.Capabilities = mcp.ClientCapabilities{
-		Experimental: make(map[string]interface{}),
-		Roots:        nil,
-		Sampling:     nil,
-	}
-	_, err := c.client.Initialize(ctx, initRequest)
-	if err != nil {
-		return err
-	}
-	internal.Logf("<%s> Successfully initialized MCP client", c.name)
-
-	// Start capability discovery
-	internal.LogInfoWithFields("client", "Starting MCP capability discovery", map[string]interface{}{
-		"server": c.name,
-	})
-
-	err = c.addToolsToServer(ctx, mcpServer, userEmail, requiresToken, tokenStore, serverName, setupBaseURL, tokenSetup, session)
-	if err != nil {
-		return err
-	}
-	_ = c.addPromptsToServer(ctx, mcpServer)
-	_ = c.addResourcesToServer(ctx, mcpServer)
-	_ = c.addResourceTemplatesToServer(ctx, mcpServer)
-
-	internal.LogInfoWithFields("client", "MCP capability discovery completed", map[string]interface{}{
-		"server":            c.name,
-		"userTokenRequired": requiresToken,
-	})
-
-	if c.needPing {
-		go c.startPingTask(ctx)
-	}
-	return nil
-}
-
 // startPingTask runs a goroutine that pings the MCP server every 30 seconds.
 // The goroutine lifecycle is tied to the provided context:
 // - For stdio clients: context is cancelled when the request ends, stopping pings

internal/client/session_manager.go

@@ -10,7 +10,9 @@ import (
 
 	"github.com/dgellow/mcp-front/internal"
 	"github.com/dgellow/mcp-front/internal/config"
+	"github.com/dgellow/mcp-front/internal/storage"
 	"github.com/mark3labs/mcp-go/mcp"
+	"github.com/mark3labs/mcp-go/server"
 )
 
 var (
@@ -217,6 +219,75 @@ func (s *StdioSession) GetClient() *Client {
 	return s.client
 }
 
+// DiscoverAndRegisterCapabilities discovers and registers capabilities from the stdio process
+func (s *StdioSession) DiscoverAndRegisterCapabilities(
+	ctx context.Context,
+	mcpServer *server.MCPServer,
+	userEmail string,
+	requiresToken bool,
+	tokenStore storage.UserTokenStore,
+	serverName string,
+	setupBaseURL string,
+	tokenSetup *config.TokenSetupConfig,
+	session server.ClientSession,
+) error {
+	// Initialize the client
+	if s.client.needManualStart {
+		if err := s.client.client.Start(ctx); err != nil {
+			return err
+		}
+	}
+
+	initRequest := mcp.InitializeRequest{}
+	initRequest.Params.ProtocolVersion = mcp.LATEST_PROTOCOL_VERSION
+	initRequest.Params.ClientInfo = mcp.Implementation{
+		Name:    serverName,
+		Version: "1.0",
+	}
+	initRequest.Params.Capabilities = mcp.ClientCapabilities{
+		Experimental: make(map[string]interface{}),
+		Roots:        nil,
+		Sampling:     nil,
+	}
+
+	_, err := s.client.client.Initialize(ctx, initRequest)
+	if err != nil {
+		return err
+	}
+	internal.Logf("<%s> Successfully initialized MCP client", serverName)
+
+	// Start capability discovery
+	internal.LogInfoWithFields("client", "Starting MCP capability discovery", map[string]interface{}{
+		"server": serverName,
+	})
+
+	// Discover and register tools
+	if err := s.client.addToolsToServer(ctx, mcpServer, userEmail, requiresToken, tokenStore, serverName, setupBaseURL, tokenSetup, session); err != nil {
+		return err
+	}
+
+	// Discover and register prompts
+	_ = s.client.addPromptsToServer(ctx, mcpServer)
+
+	// Discover and register resources
+	_ = s.client.addResourcesToServer(ctx, mcpServer)
+
+	// Discover and register resource templates
+	_ = s.client.addResourceTemplatesToServer(ctx, mcpServer)
+
+	internal.LogInfoWithFields("client", "MCP capability discovery completed", map[string]interface{}{
+		"server":            serverName,
+		"userTokenRequired": requiresToken,
+	})
+
+	// Start ping task if needed
+	if s.client.needPing {
+		go s.client.startPingTask(ctx)
+	}
+
+	return nil
+}
+
 // checkUserLimits verifies user hasn't exceeded session limits
 func (sm *StdioSessionManager) checkUserLimits(userEmail string) error {
 	if userEmail == "" {