Add Go AST analysis tools and refactor to use common walk code

CONTEXT.md

@@ -16,17 +16,74 @@
 gocp is a Go MCP (Model Context Protocol) server that provides tools for building and executing Go code. It uses the go-mcp library to implement the MCP protocol.
 
 ## Key Files
-- `main.go`: MCP server implementation with build_and_run_go tool
+- `main.go`: MCP server implementation with tools and handlers
+- `ast.go`: Go AST parsing and code analysis functionality
 - `go.mod`: Module definition with go-mcp dependency
 
 ## Tool Details
-- **build_and_run_go**: Executes Go code using `go run`
-  - Parameters:
-    - `code` (required): Go source code to execute
-    - `timeout` (optional): Timeout in seconds (default: 30)
-  - Returns JSON with:
-    - `stdout`: Standard output
-    - `stderr`: Standard error
-    - `exit_code`: Process exit code
-    - `error`: Error message if any
-  - Creates temporary directories with `gocp-*` prefix
+
+### build_and_run_go
+Executes Go code using `go run`
+- Parameters:
+  - `code` (required): Go source code to execute
+  - `timeout` (optional): Timeout in seconds (default: 30)
+- Returns JSON with:
+  - `stdout`: Standard output
+  - `stderr`: Standard error
+  - `exit_code`: Process exit code
+  - `error`: Error message if any
+- Creates temporary directories with `gocp-*` prefix
+
+### find_symbols
+Find all functions, types, interfaces, constants, and variables by name/pattern
+- Parameters:
+  - `dir` (optional): Directory to search (default: current directory)
+  - `pattern` (optional): Symbol name pattern to search for (case-insensitive substring match)
+- Returns JSON array of symbols with:
+  - `name`: Symbol name
+  - `type`: Symbol type (function, struct, interface, constant, variable)
+  - `package`: Package name
+  - `file`: File path
+  - `line`: Line number
+  - `column`: Column number
+  - `exported`: Whether the symbol is exported
+
+### get_type_info
+Get detailed information about a type including fields, methods, and embedded types
+- Parameters:
+  - `dir` (optional): Directory to search (default: current directory)
+  - `type` (required): Type name to get information for
+- Returns JSON with:
+  - `name`: Type name
+  - `package`: Package name
+  - `file`: File path
+  - `line`: Line number
+  - `kind`: Type kind (struct, interface, alias, other)
+  - `fields`: Array of field information (for structs)
+  - `methods`: Array of methods
+  - `embedded`: Array of embedded type names
+  - `interface`: Array of interface methods (for interfaces)
+  - `underlying`: Underlying type (for aliases)
+
+### find_references
+Find all references to a symbol (function calls, type usage, etc.)
+- Parameters:
+  - `dir` (optional): Directory to search (default: current directory)
+  - `symbol` (required): Symbol name to find references for
+- Returns JSON array of references with:
+  - `file`: File path
+  - `line`: Line number
+  - `column`: Column number
+  - `context`: Code context around the reference
+  - `kind`: Reference kind (identifier, selector)
+
+### list_packages
+List all Go packages in directory tree
+- Parameters:
+  - `dir` (optional): Directory to search (default: current directory)
+- Returns JSON array of packages with:
+  - `import_path`: Import path relative to search directory
+  - `name`: Package name
+  - `dir`: Directory path
+  - `go_files`: List of Go source files
+  - `imports`: List of imported packages

ast.go

@@ -0,0 +1,543 @@
+package main
+
+import (
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type Symbol struct {
+	Name     string `json:"name"`
+	Type     string `json:"type"`
+	Package  string `json:"package"`
+	File     string `json:"file"`
+	Line     int    `json:"line"`
+	Column   int    `json:"column"`
+	Exported bool   `json:"exported"`
+}
+
+type TypeInfo struct {
+	Name      string                 `json:"name"`
+	Package   string                 `json:"package"`
+	File      string                 `json:"file"`
+	Line      int                    `json:"line"`
+	Kind      string                 `json:"kind"`
+	Fields    []FieldInfo            `json:"fields,omitempty"`
+	Methods   []MethodInfo           `json:"methods,omitempty"`
+	Embedded  []string               `json:"embedded,omitempty"`
+	Interface []MethodInfo           `json:"interface,omitempty"`
+	Underlying string                `json:"underlying,omitempty"`
+}
+
+type FieldInfo struct {
+	Name     string `json:"name"`
+	Type     string `json:"type"`
+	Tag      string `json:"tag,omitempty"`
+	Exported bool   `json:"exported"`
+}
+
+type MethodInfo struct {
+	Name      string `json:"name"`
+	Signature string `json:"signature"`
+	Receiver  string `json:"receiver,omitempty"`
+	Exported  bool   `json:"exported"`
+}
+
+type Reference struct {
+	File     string `json:"file"`
+	Line     int    `json:"line"`
+	Column   int    `json:"column"`
+	Context  string `json:"context"`
+	Kind     string `json:"kind"`
+}
+
+type Package struct {
+	ImportPath string   `json:"import_path"`
+	Name       string   `json:"name"`
+	Dir        string   `json:"dir"`
+	GoFiles    []string `json:"go_files"`
+	Imports    []string `json:"imports"`
+}
+
+type fileVisitor func(path string, src []byte, file *ast.File, fset *token.FileSet) error
+
+func walkGoFiles(dir string, visitor fileVisitor) error {
+	fset := token.NewFileSet()
+
+	return filepath.WalkDir(dir, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if d.IsDir() || !strings.HasSuffix(path, ".go") || strings.Contains(path, "vendor/") {
+			return nil
+		}
+
+		src, err := os.ReadFile(path)
+		if err != nil {
+			return nil
+		}
+
+		file, err := parser.ParseFile(fset, path, src, parser.ParseComments)
+		if err != nil {
+			return nil
+		}
+
+		return visitor(path, src, file, fset)
+	})
+}
+
+func findSymbols(dir string, pattern string) ([]Symbol, error) {
+	var symbols []Symbol
+
+	err := walkGoFiles(dir, func(path string, src []byte, file *ast.File, fset *token.FileSet) error {
+		if strings.HasSuffix(path, "_test.go") && !strings.Contains(pattern, "Test") {
+			return nil
+		}
+
+		pkgName := file.Name.Name
+
+		ast.Inspect(file, func(n ast.Node) bool {
+			switch decl := n.(type) {
+			case *ast.FuncDecl:
+				name := decl.Name.Name
+				if matchesPattern(name, pattern) {
+					pos := fset.Position(decl.Pos())
+					symbols = append(symbols, Symbol{
+						Name:     name,
+						Type:     "function",
+						Package:  pkgName,
+						File:     path,
+						Line:     pos.Line,
+						Column:   pos.Column,
+						Exported: ast.IsExported(name),
+					})
+				}
+
+			case *ast.GenDecl:
+				for _, spec := range decl.Specs {
+					switch s := spec.(type) {
+					case *ast.TypeSpec:
+						name := s.Name.Name
+						if matchesPattern(name, pattern) {
+							pos := fset.Position(s.Pos())
+							kind := "type"
+							switch s.Type.(type) {
+							case *ast.InterfaceType:
+								kind = "interface"
+							case *ast.StructType:
+								kind = "struct"
+							}
+							symbols = append(symbols, Symbol{
+								Name:     name,
+								Type:     kind,
+								Package:  pkgName,
+								File:     path,
+								Line:     pos.Line,
+								Column:   pos.Column,
+								Exported: ast.IsExported(name),
+							})
+						}
+
+					case *ast.ValueSpec:
+						for _, name := range s.Names {
+							if matchesPattern(name.Name, pattern) {
+								pos := fset.Position(name.Pos())
+								kind := "variable"
+								if decl.Tok == token.CONST {
+									kind = "constant"
+								}
+								symbols = append(symbols, Symbol{
+									Name:     name.Name,
+									Type:     kind,
+									Package:  pkgName,
+									File:     path,
+									Line:     pos.Line,
+									Column:   pos.Column,
+									Exported: ast.IsExported(name.Name),
+								})
+							}
+						}
+					}
+				}
+			}
+			return true
+		})
+
+		return nil
+	})
+
+	return symbols, err
+}
+
+func getTypeInfo(dir string, typeName string) (*TypeInfo, error) {
+	var result *TypeInfo
+	
+	err := walkGoFiles(dir, func(path string, src []byte, file *ast.File, fset *token.FileSet) error {
+		if result != nil {
+			return nil
+		}
+
+		ast.Inspect(file, func(n ast.Node) bool {
+			if result != nil {
+				return false
+			}
+
+			switch decl := n.(type) {
+			case *ast.GenDecl:
+				for _, spec := range decl.Specs {
+					if ts, ok := spec.(*ast.TypeSpec); ok && ts.Name.Name == typeName {
+						pos := fset.Position(ts.Pos())
+						info := &TypeInfo{
+							Name:    typeName,
+							Package: file.Name.Name,
+							File:    path,
+							Line:    pos.Line,
+						}
+
+						switch t := ts.Type.(type) {
+						case *ast.StructType:
+							info.Kind = "struct"
+							info.Fields = extractFields(t)
+							info.Embedded = extractEmbedded(t)
+
+						case *ast.InterfaceType:
+							info.Kind = "interface"
+							info.Interface = extractInterfaceMethods(t)
+
+						case *ast.Ident:
+							info.Kind = "alias"
+							info.Underlying = t.Name
+
+						case *ast.SelectorExpr:
+							info.Kind = "alias"
+							if x, ok := t.X.(*ast.Ident); ok {
+								info.Underlying = x.Name + "." + t.Sel.Name
+							}
+
+						default:
+							info.Kind = "other"
+						}
+
+						info.Methods = extractMethods(file, typeName)
+						result = info
+						return false
+					}
+				}
+			}
+			return true
+		})
+
+		return nil
+	})
+
+	if result == nil && err == nil {
+		return nil, fmt.Errorf("type %s not found", typeName)
+	}
+
+	return result, err
+}
+
+func findReferences(dir string, symbol string) ([]Reference, error) {
+	var refs []Reference
+
+	err := walkGoFiles(dir, func(path string, src []byte, file *ast.File, fset *token.FileSet) error {
+
+		ast.Inspect(file, func(n ast.Node) bool {
+			switch node := n.(type) {
+			case *ast.Ident:
+				if node.Name == symbol {
+					pos := fset.Position(node.Pos())
+					kind := identifyReferenceKind(node)
+					context := extractContext(src, pos)
+					
+					refs = append(refs, Reference{
+						File:    path,
+						Line:    pos.Line,
+						Column:  pos.Column,
+						Context: context,
+						Kind:    kind,
+					})
+				}
+
+			case *ast.SelectorExpr:
+				if node.Sel.Name == symbol {
+					pos := fset.Position(node.Sel.Pos())
+					context := extractContext(src, pos)
+					
+					refs = append(refs, Reference{
+						File:    path,
+						Line:    pos.Line,
+						Column:  pos.Column,
+						Context: context,
+						Kind:    "selector",
+					})
+				}
+			}
+			return true
+		})
+
+		return nil
+	})
+
+	return refs, err
+}
+
+func listPackages(dir string, includeTests bool) ([]Package, error) {
+	packages := make(map[string]*Package)
+
+	err := walkGoFiles(dir, func(path string, src []byte, file *ast.File, fset *token.FileSet) error {
+		// Skip test files if not requested
+		if !includeTests && strings.HasSuffix(path, "_test.go") {
+			return nil
+		}
+
+		pkgDir := filepath.Dir(path)
+		
+		// Initialize package if not seen before
+		if _, exists := packages[pkgDir]; !exists {
+			importPath := strings.TrimPrefix(pkgDir, dir)
+			importPath = strings.TrimPrefix(importPath, "/")
+			if importPath == "" {
+				importPath = "."
+			}
+
+			packages[pkgDir] = &Package{
+				ImportPath: importPath,
+				Name:       file.Name.Name,
+				Dir:        pkgDir,
+				GoFiles:    []string{},
+				Imports:    []string{},
+			}
+		}
+
+		// Add file to package
+		fileName := filepath.Base(path)
+		packages[pkgDir].GoFiles = append(packages[pkgDir].GoFiles, fileName)
+		
+		// Collect unique imports
+		imports := make(map[string]bool)
+		for _, imp := range file.Imports {
+			importPath := strings.Trim(imp.Path.Value, `"`)
+			imports[importPath] = true
+		}
+		
+		// Merge imports into package
+		existingImports := make(map[string]bool)
+		for _, imp := range packages[pkgDir].Imports {
+			existingImports[imp] = true
+		}
+		for imp := range imports {
+			if !existingImports[imp] {
+				packages[pkgDir].Imports = append(packages[pkgDir].Imports, imp)
+			}
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	var result []Package
+	for _, pkg := range packages {
+		result = append(result, *pkg)
+	}
+
+	return result, nil
+}
+
+func matchesPattern(name, pattern string) bool {
+	if pattern == "" {
+		return true
+	}
+	pattern = strings.ToLower(pattern)
+	name = strings.ToLower(name)
+	return strings.Contains(name, pattern)
+}
+
+func extractFields(st *ast.StructType) []FieldInfo {
+	var fields []FieldInfo
+	
+	for _, field := range st.Fields.List {
+		fieldType := exprToString(field.Type)
+		tag := ""
+		if field.Tag != nil {
+			tag = field.Tag.Value
+		}
+
+		if len(field.Names) == 0 {
+			fields = append(fields, FieldInfo{
+				Name:     "",
+				Type:     fieldType,
+				Tag:      tag,
+				Exported: true,
+			})
+		} else {
+			for _, name := range field.Names {
+				fields = append(fields, FieldInfo{
+					Name:     name.Name,
+					Type:     fieldType,
+					Tag:      tag,
+					Exported: ast.IsExported(name.Name),
+				})
+			}
+		}
+	}
+	
+	return fields
+}
+
+func extractEmbedded(st *ast.StructType) []string {
+	var embedded []string
+	
+	for _, field := range st.Fields.List {
+		if len(field.Names) == 0 {
+			embedded = append(embedded, exprToString(field.Type))
+		}
+	}
+	
+	return embedded
+}
+
+func extractInterfaceMethods(it *ast.InterfaceType) []MethodInfo {
+	var methods []MethodInfo
+	
+	for _, method := range it.Methods.List {
+		if len(method.Names) > 0 {
+			for _, name := range method.Names {
+				sig := exprToString(method.Type)
+				methods = append(methods, MethodInfo{
+					Name:      name.Name,
+					Signature: sig,
+					Exported:  ast.IsExported(name.Name),
+				})
+			}
+		}
+	}
+	
+	return methods
+}
+
+func extractMethods(file *ast.File, typeName string) []MethodInfo {
+	var methods []MethodInfo
+	
+	for _, decl := range file.Decls {
+		if fn, ok := decl.(*ast.FuncDecl); ok && fn.Recv != nil {
+			for _, recv := range fn.Recv.List {
+				recvType := exprToString(recv.Type)
+				if strings.Contains(recvType, typeName) {
+					sig := funcSignature(fn.Type)
+					methods = append(methods, MethodInfo{
+						Name:      fn.Name.Name,
+						Signature: sig,
+						Receiver:  recvType,
+						Exported:  ast.IsExported(fn.Name.Name),
+					})
+				}
+			}
+		}
+	}
+	
+	return methods
+}
+
+func exprToString(expr ast.Expr) string {
+	switch e := expr.(type) {
+	case *ast.Ident:
+		return e.Name
+	case *ast.StarExpr:
+		return "*" + exprToString(e.X)
+	case *ast.SelectorExpr:
+		return exprToString(e.X) + "." + e.Sel.Name
+	case *ast.ArrayType:
+		if e.Len == nil {
+			return "[]" + exprToString(e.Elt)
+		}
+		return "[" + exprToString(e.Len) + "]" + exprToString(e.Elt)
+	case *ast.MapType:
+		return "map[" + exprToString(e.Key) + "]" + exprToString(e.Value)
+	case *ast.InterfaceType:
+		if len(e.Methods.List) == 0 {
+			return "interface{}"
+		}
+		return "interface{...}"
+	case *ast.FuncType:
+		return funcSignature(e)
+	case *ast.ChanType:
+		switch e.Dir {
+		case ast.SEND:
+			return "chan<- " + exprToString(e.Value)
+		case ast.RECV:
+			return "<-chan " + exprToString(e.Value)
+		default:
+			return "chan " + exprToString(e.Value)
+		}
+	case *ast.BasicLit:
+		return e.Value
+	default:
+		return fmt.Sprintf("%T", expr)
+	}
+}
+
+func funcSignature(fn *ast.FuncType) string {
+	params := fieldListToString(fn.Params)
+	results := fieldListToString(fn.Results)
+	
+	if results == "" {
+		return fmt.Sprintf("func(%s)", params)
+	}
+	return fmt.Sprintf("func(%s) %s", params, results)
+}
+
+func fieldListToString(fl *ast.FieldList) string {
+	if fl == nil || len(fl.List) == 0 {
+		return ""
+	}
+	
+	var parts []string
+	for _, field := range fl.List {
+		fieldType := exprToString(field.Type)
+		if len(field.Names) == 0 {
+			parts = append(parts, fieldType)
+		} else {
+			for _, name := range field.Names {
+				parts = append(parts, name.Name+" "+fieldType)
+			}
+		}
+	}
+	
+	if len(parts) == 1 && !strings.Contains(parts[0], " ") {
+		return parts[0]
+	}
+	return "(" + strings.Join(parts, ", ") + ")"
+}
+
+func identifyReferenceKind(ident *ast.Ident) string {
+	return "identifier"
+}
+
+func extractContext(src []byte, pos token.Position) string {
+	lines := strings.Split(string(src), "\n")
+	if pos.Line <= 0 || pos.Line > len(lines) {
+		return ""
+	}
+	
+	start := pos.Line - 2
+	if start < 0 {
+		start = 0
+	}
+	end := pos.Line + 1
+	if end > len(lines) {
+		end = len(lines)
+	}
+	
+	context := strings.Join(lines[start:end], "\n")
+	return strings.TrimSpace(context)
+}

go.mod

@@ -1,5 +1,13 @@
 module github.com/flamingcow/gocp
 
-go 1.21
+go 1.23.2
 
-require github.com/mark3labs/mcp-go v0.1.0
+toolchain go1.24.4
+
+require github.com/mark3labs/mcp-go v0.32.0
+
+require (
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/spf13/cast v1.7.1 // indirect
+	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
+)

go.sum

@@ -0,0 +1,26 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
+github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/mark3labs/mcp-go v0.32.0 h1:fgwmbfL2gbd67obg57OfV2Dnrhs1HtSdlY/i5fn7MU8=
+github.com/mark3labs/mcp-go v0.32.0/go.mod h1:rXqOudj/djTORU/ThxYx8fqEVj/5pvTuuebQ2RC7uk4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+github.com/spf13/cast v1.7.1 h1:cuNEagBQEHWN1FnbGEjCXL2szYEXqfJPbP2HNUaca9Y=
+github.com/spf13/cast v1.7.1/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
+github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -22,119 +22,227 @@ type RunResult struct {
 }
 
 func main() {
-	// Create MCP server
-	s := server.NewMCPServer(
-		"go-executor",
+	mcpServer := server.NewMCPServer(
+		"gocp",
 		"1.0.0",
-		server.WithToolCapabilities(true),
+		server.WithToolCapabilities(false),
 	)
 
 	// Define the build_and_run_go tool
-	buildAndRunTool := mcp.NewTool(
-		"build_and_run_go",
+	buildAndRunTool := mcp.NewTool("build_and_run_go",
 		mcp.WithDescription("Build and execute Go code"),
-		mcp.WithString("code", mcp.Required(), mcp.Description("The Go source code to build and run")),
-		mcp.WithNumber("timeout", mcp.Description("Timeout in seconds (default: 30)")),
+		mcp.WithString("code",
+			mcp.Required(),
+			mcp.Description("The Go source code to build and run"),
+		),
+		mcp.WithNumber("timeout",
+			mcp.Description("Timeout in seconds (default: 30)"),
+		),
 	)
+	mcpServer.AddTool(buildAndRunTool, buildAndRunHandler)
 
-	// Add tool handler
-	s.AddTool(buildAndRunTool, buildAndRunHandler)
+	// Define the find_symbols tool
+	findSymbolsTool := mcp.NewTool("find_symbols",
+		mcp.WithDescription("Find all functions, types, interfaces, constants, and variables by name/pattern"),
+		mcp.WithString("dir",
+			mcp.Description("Directory to search (default: current directory)"),
+		),
+		mcp.WithString("pattern",
+			mcp.Description("Symbol name pattern to search for (case-insensitive substring match)"),
+		),
+	)
+	mcpServer.AddTool(findSymbolsTool, findSymbolsHandler)
+
+	// Define the get_type_info tool
+	getTypeInfoTool := mcp.NewTool("get_type_info",
+		mcp.WithDescription("Get detailed information about a type including fields, methods, and embedded types"),
+		mcp.WithString("dir",
+			mcp.Description("Directory to search (default: current directory)"),
+		),
+		mcp.WithString("type",
+			mcp.Required(),
+			mcp.Description("Type name to get information for"),
+		),
+	)
+	mcpServer.AddTool(getTypeInfoTool, getTypeInfoHandler)
+
+	// Define the find_references tool
+	findReferencesTool := mcp.NewTool("find_references",
+		mcp.WithDescription("Find all references to a symbol (function calls, type usage, etc.)"),
+		mcp.WithString("dir",
+			mcp.Description("Directory to search (default: current directory)"),
+		),
+		mcp.WithString("symbol",
+			mcp.Required(),
+			mcp.Description("Symbol name to find references for"),
+		),
+	)
+	mcpServer.AddTool(findReferencesTool, findReferencesHandler)
+
+	// Define the list_packages tool
+	listPackagesTool := mcp.NewTool("list_packages",
+		mcp.WithDescription("List all Go packages in directory tree"),
+		mcp.WithString("dir",
+			mcp.Description("Directory to search (default: current directory)"),
+		),
+		mcp.WithBoolean("include_tests",
+			mcp.Description("Include test files in package listings (default: false)"),
+		),
+	)
+	mcpServer.AddTool(listPackagesTool, listPackagesHandler)
 
 	// Start the server
-	if err := s.Serve(); err != nil {
+	if err := server.ServeStdio(mcpServer); err != nil {
 		fmt.Fprintf(os.Stderr, "Server error: %v\n", err)
 		os.Exit(1)
 	}
 }
 
-func buildAndRunHandler(ctx context.Context, args map[string]interface{}) (*mcp.CallToolResult, error) {
-	// Extract code parameter
-	code, ok := args["code"].(string)
-	if !ok {
-		return nil, fmt.Errorf("code parameter is required and must be a string")
+func buildAndRunHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	code, err := request.RequireString("code")
+	if err != nil {
+		return mcp.NewToolResultError(err.Error()), nil
 	}
 
-	// Extract timeout parameter (optional)
-	timeout := 30.0
-	if t, ok := args["timeout"].(float64); ok {
-		timeout = t
-	}
+	timeout := request.GetFloat("timeout", 30.0)
 
-	// Build and run the code
-	stdout, stderr, exitCode, err := buildAndRunGo(code, time.Duration(timeout)*time.Second)
+	stdout, stderr, exitCode, runErr := buildAndRunGo(code, time.Duration(timeout)*time.Second)
 	
-	// Create structured result
 	result := RunResult{
 		Stdout:   stdout,
 		Stderr:   stderr,
 		ExitCode: exitCode,
 	}
 	
-	if err != nil {
-		result.Error = err.Error()
+	if runErr != nil {
+		result.Error = runErr.Error()
 	}
 
-	// Convert to JSON
 	jsonData, err := json.Marshal(result)
 	if err != nil {
-		return nil, fmt.Errorf("failed to marshal result: %w", err)
+		return mcp.NewToolResultError(fmt.Sprintf("failed to marshal result: %v", err)), nil
 	}
 
-	return mcp.NewCallToolResult(
-		mcp.NewTextContent(string(jsonData)),
-	), nil
+	return mcp.NewToolResultText(string(jsonData)), nil
 }
 
 func buildAndRunGo(code string, timeout time.Duration) (stdout, stderr string, exitCode int, err error) {
-	// Create temporary directory
 	tmpDir, err := os.MkdirTemp("", "gocp-*")
 	if err != nil {
 		return "", "", -1, fmt.Errorf("failed to create temp dir: %w", err)
 	}
 	defer os.RemoveAll(tmpDir)
 
-	// Write code to temporary file
 	tmpFile := filepath.Join(tmpDir, "main.go")
 	if err := os.WriteFile(tmpFile, []byte(code), 0644); err != nil {
 		return "", "", -1, fmt.Errorf("failed to write code: %w", err)
 	}
 
-	// Create context with timeout
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 
-	// Initialize go.mod in temp directory
 	modCmd := exec.CommandContext(ctx, "go", "mod", "init", "temp")
 	modCmd.Dir = tmpDir
 	if err := modCmd.Run(); err != nil {
 		return "", "", -1, fmt.Errorf("failed to initialize go.mod: %w", err)
 	}
 
-	// Run the code directly with go run
 	runCmd := exec.CommandContext(ctx, "go", "run", tmpFile)
 	runCmd.Dir = tmpDir
 	
-	// Capture stdout and stderr separately
 	var stdoutBuf, stderrBuf bytes.Buffer
 	runCmd.Stdout = &stdoutBuf
 	runCmd.Stderr = &stderrBuf
 	
-	// Run the command
 	err = runCmd.Run()
 	
-	// Get exit code
 	exitCode = 0
 	if err != nil {
 		if exitErr, ok := err.(*exec.ExitError); ok {
 			exitCode = exitErr.ExitCode()
-			err = nil // Clear error since we got the exit code
+			err = nil
 		} else if ctx.Err() == context.DeadlineExceeded {
 			return stdoutBuf.String(), stderrBuf.String(), -1, fmt.Errorf("execution timeout exceeded")
 		} else {
-			// Some other error occurred
 			return stdoutBuf.String(), stderrBuf.String(), -1, err
 		}
 	}
 
 	return stdoutBuf.String(), stderrBuf.String(), exitCode, nil
+}
+
+func findSymbolsHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	dir := request.GetString("dir", "./")
+	pattern := request.GetString("pattern", "")
+
+	symbols, err := findSymbols(dir, pattern)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to find symbols: %v", err)), nil
+	}
+
+	jsonData, err := json.Marshal(symbols)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to marshal symbols: %v", err)), nil
+	}
+
+	return mcp.NewToolResultText(string(jsonData)), nil
+}
+
+func getTypeInfoHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	dir := request.GetString("dir", "./")
+
+	typeName, err := request.RequireString("type")
+	if err != nil {
+		return mcp.NewToolResultError(err.Error()), nil
+	}
+
+	info, err := getTypeInfo(dir, typeName)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to get type info: %v", err)), nil
+	}
+
+	jsonData, err := json.Marshal(info)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to marshal type info: %v", err)), nil
+	}
+
+	return mcp.NewToolResultText(string(jsonData)), nil
+}
+
+func findReferencesHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	dir := request.GetString("dir", "./")
+
+	symbol, err := request.RequireString("symbol")
+	if err != nil {
+		return mcp.NewToolResultError(err.Error()), nil
+	}
+
+	refs, err := findReferences(dir, symbol)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to find references: %v", err)), nil
+	}
+
+	jsonData, err := json.Marshal(refs)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to marshal references: %v", err)), nil
+	}
+
+	return mcp.NewToolResultText(string(jsonData)), nil
+}
+
+func listPackagesHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	dir := request.GetString("dir", "./")
+	includeTests := request.GetBool("include_tests", false)
+
+	packages, err := listPackages(dir, includeTests)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to list packages: %v", err)), nil
+	}
+
+	jsonData, err := json.Marshal(packages)
+	if err != nil {
+		return mcp.NewToolResultError(fmt.Sprintf("failed to marshal packages: %v", err)), nil
+	}
+
+	return mcp.NewToolResultText(string(jsonData)), nil
 }