feat(mcp): add stdio transport for Glama registry compatibility

Add --stdio flag to gosqlx-mcp binary, enabling it to serve the MCP
protocol over stdin/stdout when spawned as a subprocess by mcp-proxy.

Glama's test infrastructure wraps any CMD with `mcp-proxy --`, which
expects a stdio-based MCP subprocess. This change allows Glama to
inspect tools and run server checks, unlocking the "Server inspectable"
and "Tool detection" score items for AAA registry rating.

The existing HTTP transport (default) is unchanged.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 2 people

cmd/gosqlx-mcp/main.go

@@ -42,6 +42,7 @@ import (
 
 	"github.com/ajitpratap0/GoSQLX/pkg/gosqlx"
 	gosqlxmcp "github.com/ajitpratap0/GoSQLX/pkg/mcp"
+	mcpserver "github.com/mark3labs/mcp-go/server"
 )
 
 func main() {
@@ -52,6 +53,31 @@ func main() {
 }
 
 func run() error {
+	// Check for --stdio flag (used when spawned by mcp-proxy as a subprocess).
+	for _, arg := range os.Args[1:] {
+		if arg == "--stdio" {
+			return runStdio()
+		}
+	}
+	return runHTTP()
+}
+
+// runStdio serves the MCP protocol over stdin/stdout.
+// This mode is used when the binary is spawned by mcp-proxy.
+func runStdio() error {
+	cfg := gosqlxmcp.DefaultConfig()
+	srv := gosqlxmcp.New(cfg)
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	stdioSrv := mcpserver.NewStdioServer(srv.MCPServer())
+	stdioSrv.SetErrorLogger(log.New(os.Stderr, "gosqlx-mcp: ", log.LstdFlags))
+	return stdioSrv.Listen(ctx, os.Stdin, os.Stdout)
+}
+
+// runHTTP serves the MCP protocol over streamable HTTP transport.
+func runHTTP() error {
 	cfg, err := gosqlxmcp.LoadConfig()
 	if err != nil {
 		return fmt.Errorf("configuration error: %w", err)

pkg/mcp/server.go

@@ -55,6 +55,12 @@ func (s *Server) Cfg() *Config {
 	return s.cfg
 }
 
+// MCPServer returns the underlying MCPServer for use with alternative transports
+// such as stdio (mcpserver.NewStdioServer).
+func (s *Server) MCPServer() *mcpserver.MCPServer {
+	return s.mcpSrv
+}
+
 // Start binds to cfg.Addr() and serves using streamable HTTP transport.
 // It blocks until ctx is cancelled or a fatal error occurs.
 func (s *Server) Start(ctx context.Context) error {