Repository: mark3labs/mcp-go

Issue:
`Arguments` type is too much strict
I believe that for smoother MCP calls, we should change the type of `Params.Arguments` to `interface{}`.

Currently, `Params.Arguments` in `mcp.CallToolRequest` is defined as a map type, which I assume was intended to let MCP server developers own the argument type. However, using a map is too restrictive.

I propose changing it to `any` (or `interface{}`). Although this type is less strict, it would make it easier to convert the struct to JSON using reflection.

Discussion:
@0xNF: I agree. Currently I have to do a lot of manual parsing over the arguments that would otherwise by solved by being able to use the standard json deserializers. @douglarek: second this. Parsing the fields in `mcp.CallToolRequest` each time is a nightmare, and there is an urgent need for some helper functions such as requireInt, requireStringArray, etc.

Furthermore, the CallToolRequest struct can have a Bind(any) method to directly support parsing into a struct for field validation.@Crayzero: And the tag of Arguments shoud be omitzero. Otherwise the marshalled json would never have "arguments":{}。@jcooky: Alternatively, the arguments can be of type `json.RawMessage`. Because this type already supports `Marshal` and `Unmarshal`, developers can easily convert the message into any other struct they need.

But, I found https://github.com/mark3labs/mcp-go/pull/116
I think It's correct for this issue.@douglarek: Let's look forward to [the official implementation of mcp]( https://github.com/golang/tools/tree/master/internal/mcp) by golang/tools, and let this library rest in peace.@emicklei: > Let's look forward to [the official implementation of mcp](https://github.com/golang/tools/tree/master/internal/mcp) by golang/tools, and let this library rest in peace.

Although I also wish to have first citizen support of MCP in the Go SDK, thanks to this mark3labs pkg, the Go community can already join the AI/agent rush by building robust, fast and less-resource-hungry MCP servers. @rwjblue-glean: FWIW, I think if someone has a good idea of what should be changed here it might be easier to discuss in a PR.@pottekkat: @jcooky @0xNF would using `any` for `Params.Arguments` and then just adding something like `BindArguments` method to marshal the arguments to a struct work? Do we still need helper functions if we do this, or should we always expect to have a struct to capture the arguments?@pottekkat: @jcooky @0xNF and others, #287 fixes the issue. It changes the type of arguments to `any` and it adds helper functions to unmarshal it to a struct and getting other values. Could you check and see if this matches your expectations?

Solution patch:
diff --git a/README.md b/README.md
index ff95e1c..25b0d5a 100644
--- a/README.md
+++ b/README.md
@@ -149,9 +149,21 @@ func main() {
 
     // Add the calculator handler
     s.AddTool(calculatorTool, func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
-        op := request.Params.Arguments["operation"].(string)
-        x := request.Params.Arguments["x"].(float64)
-        y := request.Params.Arguments["y"].(float64)
+        // Using helper functions for type-safe argument access
+        op, err := request.RequireString("operation")
+        if err != nil {
+            return mcp.NewToolResultError(err.Error()), nil
+        }
+        
+        x, err := request.RequireFloat("x")
+        if err != nil {
+            return mcp.NewToolResultError(err.Error()), nil
+        }
+        
+        y, err := request.RequireFloat("y")
+        if err != nil {
+            return mcp.NewToolResultError(err.Error()), nil
+        }
 
         var result float64
         switch op {
@@ -312,9 +324,10 @@ calculatorTool := mcp.NewTool("calculate",
 )
 
 s.AddTool(calculatorTool, func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
-    op := request.Params.Arguments["operation"].(string)
-    x := request.Params.Arguments["x"].(float64)
-    y := request.Params.Arguments["y"].(float64)
+    args := request.GetArguments()
+    op := args["operation"].(string)
+    x := args["x"].(float64)
+    y := args["y"].(float64)
 
     var result float64
     switch op {
@@ -355,10 +368,11 @@ httpTool := mcp.NewTool("http_request",
 )
 
 s.AddTool(httpTool, func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
-    method := request.Params.Arguments["method"].(string)
-    url := request.Params.Arguments["url"].(string)
+    args := request.GetArguments()
+    method := args["method"].(string)
+    url := args["url"].(string)
     body := ""
-    if b, ok := request.Params.Arguments["body"].(string); ok {
+    if b, ok := args["body"].(string); ok {
         body = b
     }
 
diff --git a/examples/custom_context/main.go b/examples/custom_context/main.go
index ef2c6dd..3e7cf7b 100644
--- a/examples/custom_context/main.go
+++ b/examples/custom_context/main.go
@@ -81,7 +81,7 @@ func handleMakeAuthenticatedRequestTool(
 	ctx context.Context,
 	request mcp.CallToolRequest,
 ) (*mcp.CallToolResult, error) {
-	message, ok := request.Params.Arguments["message"].(string)
+	message, ok := request.GetArguments()["message"].(string)
 	if !ok {
 		return nil, fmt.Errorf("missing message")
 	}
diff --git a/examples/dynamic_path/main.go b/examples/dynamic_path/main.go
index 57a7de8..80d9678 100644
--- a/examples/dynamic_path/main.go
+++ b/examples/dynamic_path/main.go
@@ -20,7 +20,7 @@ func main() {
 
 	// Add a trivial tool for demonstration
 	mcpServer.AddTool(mcp.NewTool("echo"), func(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
-		return mcp.NewToolResultText(fmt.Sprintf("Echo: %v", req.Params.Arguments["message"])), nil
+		return mcp.NewToolResultText(fmt.Sprintf("Echo: %v", req.GetArguments()["message"])), nil
 	})
 
 	// Use a dynamic base path based on a path parameter (Go 1.22+)
diff --git a/examples/everything/main.go b/examples/everything/main.go
index 751d3d2..9857e8d 100644
--- a/examples/everything/main.go
+++ b/examples/everything/main.go
@@ -312,7 +312,7 @@ func handleEchoTool(
 	ctx context.Context,
 	request mcp.CallToolRequest,
 ) (*mcp.CallToolResult, error) {
-	arguments := request.Params.Arguments
+	arguments := request.GetArguments()
 	message, ok := arguments["message"].(string)
 	if !ok {
 		return nil, fmt.Errorf("invalid message argument")
@@ -331,7 +331,7 @@ func handleAddTool(
 	ctx context.Context,
 	request mcp.CallToolRequest,
 ) (*mcp.CallToolResult, error) {
-	arguments := request.Params.Arguments
+	arguments := request.GetArguments()
 	a, ok1 := arguments["a"].(float64)
 	b, ok2 := arguments["b"].(float64)
 	if !ok1 || !ok2 {
@@ -382,7 +382,7 @@ func handleLongRunningOperationTool(
 	ctx context.Context,
 	request mcp.CallToolRequest,
 ) (*mcp.CallToolResult, error) {
-	arguments := request.Params.Arguments
+	arguments := request.GetArguments()
 	progressToken := request.Params.Meta.ProgressToken
 	duration, _ := arguments["duration"].(float64)
 	steps, _ := arguments["steps"].(float64)
diff --git a/examples/typed_tools/main.go b/examples/typed_tools/main.go
new file mode 100644
index 0000000..5c49fed
--- /dev/null
+++ b/examples/typed_tools/main.go
@@ -0,0 +1,105 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/mark3labs/mcp-go/mcp"
+	"github.com/mark3labs/mcp-go/server"
+)
+
+// Define a struct for our typed arguments
+type GreetingArgs struct {
+	Name      string   `json:"name"`
+	Age       int      `json:"age"`
+	IsVIP     bool     `json:"is_vip"`
+	Languages []string `json:"languages"`
+	Metadata  struct {
+		Location string `json:"location"`
+		Timezone string `json:"timezone"`
+	} `json:"metadata"`
+}
+
+func main() {
+	// Create a new MCP server
+	s := server.NewMCPServer(
+		"Typed Tools Demo 🚀",
+		"1.0.0",
+		server.WithToolCapabilities(false),
+	)
+
+	// Add tool with complex schema
+	tool := mcp.NewTool("greeting",
+		mcp.WithDescription("Generate a personalized greeting"),
+		mcp.WithString("name",
+			mcp.Required(),
+			mcp.Description("Name of the person to greet"),
+		),
+		mcp.WithNumber("age",
+			mcp.Description("Age of the person"),
+			mcp.Min(0),
+			mcp.Max(150),
+		),
+		mcp.WithBoolean("is_vip",
+			mcp.Description("Whether the person is a VIP"),
+			mcp.DefaultBool(false),
+		),
+		mcp.WithArray("languages",
+			mcp.Description("Languages the person speaks"),
+			mcp.Items(map[string]any{"type": "string"}),
+		),
+		mcp.WithObject("metadata",
+			mcp.Description("Additional information about the person"),
+			mcp.Properties(map[string]any{
+				"location": map[string]any{
+					"type":        "string",
+					"description": "Current location",
+				},
+				"timezone": map[string]any{
+					"type":        "string",
+					"description": "Timezone",
+				},
+			}),
+		),
+	)
+
+	// Add tool handler using the typed handler
+	s.AddTool(tool, mcp.NewTypedToolHandler(typedGreetingHandler))
+
+	// Start the stdio server
+	if err := server.ServeStdio(s); err != nil {
+		fmt.Printf("Server error: %v\n", err)
+	}
+}
+
+// Our typed handler function that receives strongly-typed arguments
+func typedGreetingHandler(ctx context.Context, request mcp.CallToolRequest, args GreetingArgs) (*mcp.CallToolResult, error) {
+	if args.Name == "" {
+		return mcp.NewToolResultError("name is required"), nil
+	}
+
+	// Build a personalized greeting based on the complex arguments
+	greeting := fmt.Sprintf("Hello, %s!", args.Name)
+	
+	if args.Age > 0 {
+		greeting += fmt.Sprintf(" You are %d years old.", args.Age)
+	}
+	
+	if args.IsVIP {
+		greeting += " Welcome back, valued VIP customer!"
+	}
+	
+	if len(args.Languages) > 0 {
+		greeting += fmt.Sprintf(" You speak %d languages: %v.", len(args.Languages), args.Languages)
+	}
+	
+	if args.Metadata.Location != "" {
+		greeting += fmt.Sprintf(" I see you're from %s.", args.Metadata.Location)
+		
+		if args.Metadata.Timezone != "" {
+			greeting += fmt.Sprintf(" Your timezone is %s.", args.Metadata.Timezone)
+		}
+	}
+
+	return mcp.NewToolResultText(greeting), nil
+}
\ No newline at end of file
diff --git a/mcp/tools.go b/mcp/tools.go
index 79d66e3..f69456a 100644
--- a/mcp/tools.go
+++ b/mcp/tools.go
@@ -4,6 +4,8 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"reflect"
+	"strconv"
 )
 
 var errToolSchemaConflict = errors.New("provide either InputSchema or RawInputSchema, not both")
@@ -44,12 +46,419 @@ type CallToolResult struct {
 type CallToolRequest struct {
 	Request
 	Params struct {
-		Name      string         `json:"name"`
-		Arguments map[string]any `json:"arguments,omitempty"`
-		Meta      *Meta          `json:"_meta,omitempty"`
+		Name      string `json:"name"`
+		Arguments any    `json:"arguments,omitempty"`
+		Meta      *Meta  `json:"_meta,omitempty"`
 	} `json:"params"`
 }
 
+// GetArguments returns the Arguments as map[string]any for backward compatibility
+// If Arguments is not a map, it returns an empty map
+func (r CallToolRequest) GetArguments() map[string]any {
+	if args, ok := r.Params.Arguments.(map[string]any); ok {
+		return args
+	}
+	return nil
+}
+
+// GetRawArguments returns the Arguments as-is without type conversion
+// This allows users to access the raw arguments in any format
+func (r CallToolRequest) GetRawArguments() any {
+	return r.Params.Arguments
+}
+
+// BindArguments unmarshals the Arguments into the provided struct
+// This is useful for working with strongly-typed arguments
+func (r CallToolRequest) BindArguments(target any) error {
+	if target == nil || reflect.ValueOf(target).Kind() != reflect.Ptr {
+		return fmt.Errorf("target must be a non-nil pointer")
+	}
+
+	// Fast-path: already raw JSON
+	if raw, ok := r.Params.Arguments.(json.RawMessage); ok {
+		return json.Unmarshal(raw, target)
+	}
+
+	data, err := json.Marshal(r.Params.Arguments)
+	if err != nil {
+		return fmt.Errorf("failed to marshal arguments: %w", err)
+	}
+
+	return json.Unmarshal(data, target)
+}
+
+// GetString returns a string argument by key, or the default value if not found
+func (r CallToolRequest) GetString(key string, defaultValue string) string {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		if str, ok := val.(string); ok {
+			return str
+		}
+	}
+	return defaultValue
+}
+
+// RequireString returns a string argument by key, or an error if not found or not a string
+func (r CallToolRequest) RequireString(key string) (string, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		if str, ok := val.(string); ok {
+			return str, nil
+		}
+		return "", fmt.Errorf("argument %q is not a string", key)
+	}
+	return "", fmt.Errorf("required argument %q not found", key)
+}
+
+// GetInt returns an int argument by key, or the default value if not found
+func (r CallToolRequest) GetInt(key string, defaultValue int) int {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case int:
+			return v
+		case float64:
+			return int(v)
+		case string:
+			if i, err := strconv.Atoi(v); err == nil {
+				return i
+			}
+		}
+	}
+	return defaultValue
+}
+
+// RequireInt returns an int argument by key, or an error if not found or not convertible to int
+func (r CallToolRequest) RequireInt(key string) (int, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case int:
+			return v, nil
+		case float64:
+			return int(v), nil
+		case string:
+			if i, err := strconv.Atoi(v); err == nil {
+				return i, nil
+			}
+			return 0, fmt.Errorf("argument %q cannot be converted to int", key)
+		default:
+			return 0, fmt.Errorf("argument %q is not an int", key)
+		}
+	}
+	return 0, fmt.Errorf("required argument %q not found", key)
+}
+
+// GetFloat returns a float64 argument by key, or the default value if not found
+func (r CallToolRequest) GetFloat(key string, defaultValue float64) float64 {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case float64:
+			return v
+		case int:
+			return float64(v)
+		case string:
+			if f, err := strconv.ParseFloat(v, 64); err == nil {
+				return f
+			}
+		}
+	}
+	return defaultValue
+}
+
+// RequireFloat returns a float64 argument by key, or an error if not found or not convertible to float64
+func (r CallToolRequest) RequireFloat(key string) (float64, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case float64:
+			return v, nil
+		case int:
+			return float64(v), nil
+		case string:
+			if f, err := strconv.ParseFloat(v, 64); err == nil {
+				return f, nil
+			}
+			return 0, fmt.Errorf("argument %q cannot be converted to float64", key)
+		default:
+			return 0, fmt.Errorf("argument %q is not a float64", key)
+		}
+	}
+	return 0, fmt.Errorf("required argument %q not found", key)
+}
+
+// GetBool returns a bool argument by key, or the default value if not found
+func (r CallToolRequest) GetBool(key string, defaultValue bool) bool {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case bool:
+			return v
+		case string:
+			if b, err := strconv.ParseBool(v); err == nil {
+				return b
+			}
+		case int:
+			return v != 0
+		case float64:
+			return v != 0
+		}
+	}
+	return defaultValue
+}
+
+// RequireBool returns a bool argument by key, or an error if not found or not convertible to bool
+func (r CallToolRequest) RequireBool(key string) (bool, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case bool:
+			return v, nil
+		case string:
+			if b, err := strconv.ParseBool(v); err == nil {
+				return b, nil
+			}
+			return false, fmt.Errorf("argument %q cannot be converted to bool", key)
+		case int:
+			return v != 0, nil
+		case float64:
+			return v != 0, nil
+		default:
+			return false, fmt.Errorf("argument %q is not a bool", key)
+		}
+	}
+	return false, fmt.Errorf("required argument %q not found", key)
+}
+
+// GetStringSlice returns a string slice argument by key, or the default value if not found
+func (r CallToolRequest) GetStringSlice(key string, defaultValue []string) []string {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []string:
+			return v
+		case []any:
+			result := make([]string, 0, len(v))
+			for _, item := range v {
+				if str, ok := item.(string); ok {
+					result = append(result, str)
+				}
+			}
+			return result
+		}
+	}
+	return defaultValue
+}
+
+// RequireStringSlice returns a string slice argument by key, or an error if not found or not convertible to string slice
+func (r CallToolRequest) RequireStringSlice(key string) ([]string, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []string:
+			return v, nil
+		case []any:
+			result := make([]string, 0, len(v))
+			for i, item := range v {
+				if str, ok := item.(string); ok {
+					result = append(result, str)
+				} else {
+					return nil, fmt.Errorf("item %d in argument %q is not a string", i, key)
+				}
+			}
+			return result, nil
+		default:
+			return nil, fmt.Errorf("argument %q is not a string slice", key)
+		}
+	}
+	return nil, fmt.Errorf("required argument %q not found", key)
+}
+
+// GetIntSlice returns an int slice argument by key, or the default value if not found
+func (r CallToolRequest) GetIntSlice(key string, defaultValue []int) []int {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []int:
+			return v
+		case []any:
+			result := make([]int, 0, len(v))
+			for _, item := range v {
+				switch num := item.(type) {
+				case int:
+					result = append(result, num)
+				case float64:
+					result = append(result, int(num))
+				case string:
+					if i, err := strconv.Atoi(num); err == nil {
+						result = append(result, i)
+					}
+				}
+			}
+			return result
+		}
+	}
+	return defaultValue
+}
+
+// RequireIntSlice returns an int slice argument by key, or an error if not found or not convertible to int slice
+func (r CallToolRequest) RequireIntSlice(key string) ([]int, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []int:
+			return v, nil
+		case []any:
+			result := make([]int, 0, len(v))
+			for i, item := range v {
+				switch num := item.(type) {
+				case int:
+					result = append(result, num)
+				case float64:
+					result = append(result, int(num))
+				case string:
+					if i, err := strconv.Atoi(num); err == nil {
+						result = append(result, i)
+					} else {
+						return nil, fmt.Errorf("item %d in argument %q cannot be converted to int", i, key)
+					}
+				default:
+					return nil, fmt.Errorf("item %d in argument %q is not an int", i, key)
+				}
+			}
+			return result, nil
+		default:
+			return nil, fmt.Errorf("argument %q is not an int slice", key)
+		}
+	}
+	return nil, fmt.Errorf("required argument %q not found", key)
+}
+
+// GetFloatSlice returns a float64 slice argument by key, or the default value if not found
+func (r CallToolRequest) GetFloatSlice(key string, defaultValue []float64) []float64 {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []float64:
+			return v
+		case []any:
+			result := make([]float64, 0, len(v))
+			for _, item := range v {
+				switch num := item.(type) {
+				case float64:
+					result = append(result, num)
+				case int:
+					result = append(result, float64(num))
+				case string:
+					if f, err := strconv.ParseFloat(num, 64); err == nil {
+						result = append(result, f)
+					}
+				}
+			}
+			return result
+		}
+	}
+	return defaultValue
+}
+
+// RequireFloatSlice returns a float64 slice argument by key, or an error if not found or not convertible to float64 slice
+func (r CallToolRequest) RequireFloatSlice(key string) ([]float64, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []float64:
+			return v, nil
+		case []any:
+			result := make([]float64, 0, len(v))
+			for i, item := range v {
+				switch num := item.(type) {
+				case float64:
+					result = append(result, num)
+				case int:
+					result = append(result, float64(num))
+				case string:
+					if f, err := strconv.ParseFloat(num, 64); err == nil {
+						result = append(result, f)
+					} else {
+						return nil, fmt.Errorf("item %d in argument %q cannot be converted to float64", i, key)
+					}
+				default:
+					return nil, fmt.Errorf("item %d in argument %q is not a float64", i, key)
+				}
+			}
+			return result, nil
+		default:
+			return nil, fmt.Errorf("argument %q is not a float64 slice", key)
+		}
+	}
+	return nil, fmt.Errorf("required argument %q not found", key)
+}
+
+// GetBoolSlice returns a bool slice argument by key, or the default value if not found
+func (r CallToolRequest) GetBoolSlice(key string, defaultValue []bool) []bool {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []bool:
+			return v
+		case []any:
+			result := make([]bool, 0, len(v))
+			for _, item := range v {
+				switch b := item.(type) {
+				case bool:
+					result = append(result, b)
+				case string:
+					if parsed, err := strconv.ParseBool(b); err == nil {
+						result = append(result, parsed)
+					}
+				case int:
+					result = append(result, b != 0)
+				case float64:
+					result = append(result, b != 0)
+				}
+			}
+			return result
+		}
+	}
+	return defaultValue
+}
+
+// RequireBoolSlice returns a bool slice argument by key, or an error if not found or not convertible to bool slice
+func (r CallToolRequest) RequireBoolSlice(key string) ([]bool, error) {
+	args := r.GetArguments()
+	if val, ok := args[key]; ok {
+		switch v := val.(type) {
+		case []bool:
+			return v, nil
+		case []any:
+			result := make([]bool, 0, len(v))
+			for i, item := range v {
+				switch b := item.(type) {
+				case bool:
+					result = append(result, b)
+				case string:
+					if parsed, err := strconv.ParseBool(b); err == nil {
+						result = append(result, parsed)
+					} else {
+						return nil, fmt.Errorf("item %d in argument %q cannot be converted to bool", i, key)
+					}
+				case int:
+					result = append(result, b != 0)
+				case float64:
+					result = append(result, b != 0)
+				default:
+					return nil, fmt.Errorf("item %d in argument %q is not a bool", i, key)
+				}
+			}
+			return result, nil
+		default:
+			return nil, fmt.Errorf("argument %q is not a bool slice", key)
+		}
+	}
+	return nil, fmt.Errorf("required argument %q not found", key)
+}
+
 // ToolListChangedNotification is an optional notification from the server to
 // the client, informing it that the list of tools it offers has changed. This may
 // be issued by servers without any previous subscription from the client.
diff --git a/mcp/typed_tools.go b/mcp/typed_tools.go
new file mode 100644
index 0000000..68d8cdd
--- /dev/null
+++ b/mcp/typed_tools.go
@@ -0,0 +1,20 @@
+package mcp
+
+import (
+	"context"
+	"fmt"
+)
+
+// TypedToolHandlerFunc is a function that handles a tool call with typed arguments
+type TypedToolHandlerFunc[T any] func(ctx context.Context, request CallToolRequest, args T) (*CallToolResult, error)
+
+// NewTypedToolHandler creates a ToolHandlerFunc that automatically binds arguments to a typed struct
+func NewTypedToolHandler[T any](handler TypedToolHandlerFunc[T]) func(ctx context.Context, request CallToolRequest) (*CallToolResult, error) {
+	return func(ctx context.Context, request CallToolRequest) (*CallToolResult, error) {
+		var args T
+		if err := request.BindArguments(&args); err != nil {
+			return NewToolResultError(fmt.Sprintf("failed to bind arguments: %v", err)), nil
+		}
+		return handler(ctx, request, args)
+	}
+}
diff --git a/mcp/utils.go b/mcp/utils.go
index bf6acbd..d6d42b7 100644
--- a/mcp/utils.go
+++ b/mcp/utils.go
@@ -675,10 +675,11 @@ func ParseReadResourceResult(rawMessage *json.RawMessage) (*ReadResourceResult,
 }
 
 func ParseArgument(request CallToolRequest, key string, defaultVal any) any {
-	if _, ok := request.Params.Arguments[key]; !ok {
+	args := request.GetArguments()
+	if _, ok := args[key]; !ok {
 		return defaultVal
 	} else {
-		return request.Params.Arguments[key]
+		return args[key]
 	}
 }
 



Test patch:
diff --git a/client/inprocess_test.go b/client/inprocess_test.go
index beaa0c0..7b150e8 100644
--- a/client/inprocess_test.go
+++ b/client/inprocess_test.go
@@ -32,7 +32,7 @@ func TestInProcessMCPClient(t *testing.T) {
 			Content: []mcp.Content{
 				mcp.TextContent{
 					Type: "text",
-					Text: "Input parameter: " + request.Params.Arguments["parameter-1"].(string),
+					Text: "Input parameter: " + request.GetArguments()["parameter-1"].(string),
 				},
 				mcp.AudioContent{
 					Type:     "audio",
diff --git a/client/sse_test.go b/client/sse_test.go
index f02ed41..82e0e21 100644
--- a/client/sse_test.go
+++ b/client/sse_test.go
@@ -36,7 +36,7 @@ func TestSSEMCPClient(t *testing.T) {
 			Content: []mcp.Content{
 				mcp.TextContent{
 					Type: "text",
-					Text: "Input parameter: " + request.Params.Arguments["parameter-1"].(string),
+					Text: "Input parameter: " + request.GetArguments()["parameter-1"].(string),
 				},
 			},
 		}, nil
diff --git a/mcp/tools_test.go b/mcp/tools_test.go
index e2be72f..7f2640b 100644
--- a/mcp/tools_test.go
+++ b/mcp/tools_test.go
@@ -308,3 +308,223 @@ func TestParseToolCallToolRequest(t *testing.T) {
 	t.Logf("param15 type: %T,value:%v", param15, param15)
 
 }
+
+func TestCallToolRequestBindArguments(t *testing.T) {
+	// Define a struct to bind to
+	type TestArgs struct {
+		Name  string `json:"name"`
+		Age   int    `json:"age"`
+		Email string `json:"email"`
+	}
+
+	// Create a request with map arguments
+	req := CallToolRequest{}
+	req.Params.Name = "test-tool"
+	req.Params.Arguments = map[string]any{
+		"name":  "John Doe",
+		"age":   30,
+		"email": "john@example.com",
+	}
+
+	// Bind arguments to struct
+	var args TestArgs
+	err := req.BindArguments(&args)
+	assert.NoError(t, err)
+	assert.Equal(t, "John Doe", args.Name)
+	assert.Equal(t, 30, args.Age)
+	assert.Equal(t, "john@example.com", args.Email)
+}
+
+func TestCallToolRequestHelperFunctions(t *testing.T) {
+	// Create a request with map arguments
+	req := CallToolRequest{}
+	req.Params.Name = "test-tool"
+	req.Params.Arguments = map[string]any{
+		"string_val":       "hello",
+		"int_val":          42,
+		"float_val":        3.14,
+		"bool_val":         true,
+		"string_slice_val": []any{"one", "two", "three"},
+		"int_slice_val":    []any{1, 2, 3},
+		"float_slice_val":  []any{1.1, 2.2, 3.3},
+		"bool_slice_val":   []any{true, false, true},
+	}
+
+	// Test GetString
+	assert.Equal(t, "hello", req.GetString("string_val", "default"))
+	assert.Equal(t, "default", req.GetString("missing_val", "default"))
+
+	// Test RequireString
+	str, err := req.RequireString("string_val")
+	assert.NoError(t, err)
+	assert.Equal(t, "hello", str)
+	_, err = req.RequireString("missing_val")
+	assert.Error(t, err)
+
+	// Test GetInt
+	assert.Equal(t, 42, req.GetInt("int_val", 0))
+	assert.Equal(t, 0, req.GetInt("missing_val", 0))
+
+	// Test RequireInt
+	i, err := req.RequireInt("int_val")
+	assert.NoError(t, err)
+	assert.Equal(t, 42, i)
+	_, err = req.RequireInt("missing_val")
+	assert.Error(t, err)
+
+	// Test GetFloat
+	assert.Equal(t, 3.14, req.GetFloat("float_val", 0.0))
+	assert.Equal(t, 0.0, req.GetFloat("missing_val", 0.0))
+
+	// Test RequireFloat
+	f, err := req.RequireFloat("float_val")
+	assert.NoError(t, err)
+	assert.Equal(t, 3.14, f)
+	_, err = req.RequireFloat("missing_val")
+	assert.Error(t, err)
+
+	// Test GetBool
+	assert.Equal(t, true, req.GetBool("bool_val", false))
+	assert.Equal(t, false, req.GetBool("missing_val", false))
+
+	// Test RequireBool
+	b, err := req.RequireBool("bool_val")
+	assert.NoError(t, err)
+	assert.Equal(t, true, b)
+	_, err = req.RequireBool("missing_val")
+	assert.Error(t, err)
+
+	// Test GetStringSlice
+	assert.Equal(t, []string{"one", "two", "three"}, req.GetStringSlice("string_slice_val", nil))
+	assert.Equal(t, []string{"default"}, req.GetStringSlice("missing_val", []string{"default"}))
+
+	// Test RequireStringSlice
+	ss, err := req.RequireStringSlice("string_slice_val")
+	assert.NoError(t, err)
+	assert.Equal(t, []string{"one", "two", "three"}, ss)
+	_, err = req.RequireStringSlice("missing_val")
+	assert.Error(t, err)
+
+	// Test GetIntSlice
+	assert.Equal(t, []int{1, 2, 3}, req.GetIntSlice("int_slice_val", nil))
+	assert.Equal(t, []int{42}, req.GetIntSlice("missing_val", []int{42}))
+
+	// Test RequireIntSlice
+	is, err := req.RequireIntSlice("int_slice_val")
+	assert.NoError(t, err)
+	assert.Equal(t, []int{1, 2, 3}, is)
+	_, err = req.RequireIntSlice("missing_val")
+	assert.Error(t, err)
+
+	// Test GetFloatSlice
+	assert.Equal(t, []float64{1.1, 2.2, 3.3}, req.GetFloatSlice("float_slice_val", nil))
+	assert.Equal(t, []float64{4.4}, req.GetFloatSlice("missing_val", []float64{4.4}))
+
+	// Test RequireFloatSlice
+	fs, err := req.RequireFloatSlice("float_slice_val")
+	assert.NoError(t, err)
+	assert.Equal(t, []float64{1.1, 2.2, 3.3}, fs)
+	_, err = req.RequireFloatSlice("missing_val")
+	assert.Error(t, err)
+
+	// Test GetBoolSlice
+	assert.Equal(t, []bool{true, false, true}, req.GetBoolSlice("bool_slice_val", nil))
+	assert.Equal(t, []bool{false}, req.GetBoolSlice("missing_val", []bool{false}))
+
+	// Test RequireBoolSlice
+	bs, err := req.RequireBoolSlice("bool_slice_val")
+	assert.NoError(t, err)
+	assert.Equal(t, []bool{true, false, true}, bs)
+	_, err = req.RequireBoolSlice("missing_val")
+	assert.Error(t, err)
+}
+
+func TestFlexibleArgumentsWithMap(t *testing.T) {
+	// Create a request with map arguments
+	req := CallToolRequest{}
+	req.Params.Name = "test-tool"
+	req.Params.Arguments = map[string]any{
+		"key1": "value1",
+		"key2": 123,
+	}
+
+	// Test GetArguments
+	args := req.GetArguments()
+	assert.Equal(t, "value1", args["key1"])
+	assert.Equal(t, 123, args["key2"])
+
+	// Test GetRawArguments
+	rawArgs := req.GetRawArguments()
+	mapArgs, ok := rawArgs.(map[string]any)
+	assert.True(t, ok)
+	assert.Equal(t, "value1", mapArgs["key1"])
+	assert.Equal(t, 123, mapArgs["key2"])
+}
+
+func TestFlexibleArgumentsWithString(t *testing.T) {
+	// Create a request with non-map arguments
+	req := CallToolRequest{}
+	req.Params.Name = "test-tool"
+	req.Params.Arguments = "string-argument"
+
+	// Test GetArguments (should return empty map)
+	args := req.GetArguments()
+	assert.Empty(t, args)
+
+	// Test GetRawArguments
+	rawArgs := req.GetRawArguments()
+	strArg, ok := rawArgs.(string)
+	assert.True(t, ok)
+	assert.Equal(t, "string-argument", strArg)
+}
+
+func TestFlexibleArgumentsWithStruct(t *testing.T) {
+	// Create a custom struct
+	type CustomArgs struct {
+		Field1 string `json:"field1"`
+		Field2 int    `json:"field2"`
+	}
+
+	// Create a request with struct arguments
+	req := CallToolRequest{}
+	req.Params.Name = "test-tool"
+	req.Params.Arguments = CustomArgs{
+		Field1: "test",
+		Field2: 42,
+	}
+
+	// Test GetArguments (should return empty map)
+	args := req.GetArguments()
+	assert.Empty(t, args)
+
+	// Test GetRawArguments
+	rawArgs := req.GetRawArguments()
+	structArg, ok := rawArgs.(CustomArgs)
+	assert.True(t, ok)
+	assert.Equal(t, "test", structArg.Field1)
+	assert.Equal(t, 42, structArg.Field2)
+}
+
+func TestFlexibleArgumentsJSONMarshalUnmarshal(t *testing.T) {
+	// Create a request with map arguments
+	req := CallToolRequest{}
+	req.Params.Name = "test-tool"
+	req.Params.Arguments = map[string]any{
+		"key1": "value1",
+		"key2": 123,
+	}
+
+	// Marshal to JSON
+	data, err := json.Marshal(req)
+	assert.NoError(t, err)
+
+	// Unmarshal from JSON
+	var unmarshaledReq CallToolRequest
+	err = json.Unmarshal(data, &unmarshaledReq)
+	assert.NoError(t, err)
+
+	// Check if arguments are correctly unmarshaled
+	args := unmarshaledReq.GetArguments()
+	assert.Equal(t, "value1", args["key1"])
+	assert.Equal(t, float64(123), args["key2"]) // JSON numbers are unmarshaled as float64
+}
diff --git a/mcp/typed_tools_test.go b/mcp/typed_tools_test.go
new file mode 100644
index 0000000..109ade8
--- /dev/null
+++ b/mcp/typed_tools_test.go
@@ -0,0 +1,304 @@
+package mcp
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTypedToolHandler(t *testing.T) {
+	// Define a test struct for arguments
+	type HelloArgs struct {
+		Name    string `json:"name"`
+		Age     int    `json:"age"`
+		IsAdmin bool   `json:"is_admin"`
+	}
+
+	// Create a typed handler function
+	typedHandler := func(ctx context.Context, request CallToolRequest, args HelloArgs) (*CallToolResult, error) {
+		return NewToolResultText(args.Name), nil
+	}
+
+	// Create a wrapped handler
+	wrappedHandler := NewTypedToolHandler(typedHandler)
+
+	// Create a test request
+	req := CallToolRequest{}
+	req.Params.Name = "test-tool"
+	req.Params.Arguments = map[string]any{
+		"name":     "John Doe",
+		"age":      30,
+		"is_admin": true,
+	}
+
+	// Call the wrapped handler
+	result, err := wrappedHandler(context.Background(), req)
+
+	// Verify results
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.Equal(t, "John Doe", result.Content[0].(TextContent).Text)
+
+	// Test with invalid arguments
+	req.Params.Arguments = map[string]any{
+		"name":     123, // Wrong type
+		"age":      "thirty",
+		"is_admin": "yes",
+	}
+
+	// This should still work because of type conversion
+	result, err = wrappedHandler(context.Background(), req)
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+
+	// Test with missing required field
+	req.Params.Arguments = map[string]any{
+		"age":      30,
+		"is_admin": true,
+		// Name is missing
+	}
+
+	// This should still work but name will be empty
+	result, err = wrappedHandler(context.Background(), req)
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.Equal(t, "", result.Content[0].(TextContent).Text)
+
+	// Test with completely invalid arguments
+	req.Params.Arguments = "not a map"
+	result, err = wrappedHandler(context.Background(), req)
+	assert.NoError(t, err) // Error is wrapped in the result
+	assert.NotNil(t, result)
+	assert.True(t, result.IsError)
+}
+
+func TestTypedToolHandlerWithValidation(t *testing.T) {
+	// Define a test struct for arguments with validation
+	type CalculatorArgs struct {
+		Operation string  `json:"operation"`
+		X         float64 `json:"x"`
+		Y         float64 `json:"y"`
+	}
+
+	// Create a typed handler function with validation
+	typedHandler := func(ctx context.Context, request CallToolRequest, args CalculatorArgs) (*CallToolResult, error) {
+		// Validate operation
+		if args.Operation == "" {
+			return NewToolResultError("operation is required"), nil
+		}
+
+		var result float64
+		switch args.Operation {
+		case "add":
+			result = args.X + args.Y
+		case "subtract":
+			result = args.X - args.Y
+		case "multiply":
+			result = args.X * args.Y
+		case "divide":
+			if args.Y == 0 {
+				return NewToolResultError("division by zero"), nil
+			}
+			result = args.X / args.Y
+		default:
+			return NewToolResultError("invalid operation"), nil
+		}
+
+		return NewToolResultText(fmt.Sprintf("%.0f", result)), nil
+	}
+
+	// Create a wrapped handler
+	wrappedHandler := NewTypedToolHandler(typedHandler)
+
+	// Create a test request
+	req := CallToolRequest{}
+	req.Params.Name = "calculator"
+	req.Params.Arguments = map[string]any{
+		"operation": "add",
+		"x":         10.5,
+		"y":         5.5,
+	}
+
+	// Call the wrapped handler
+	result, err := wrappedHandler(context.Background(), req)
+
+	// Verify results
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.Equal(t, "16", result.Content[0].(TextContent).Text)
+
+	// Test division by zero
+	req.Params.Arguments = map[string]any{
+		"operation": "divide",
+		"x":         10.0,
+		"y":         0.0,
+	}
+
+	result, err = wrappedHandler(context.Background(), req)
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.True(t, result.IsError)
+	assert.Contains(t, result.Content[0].(TextContent).Text, "division by zero")
+}
+
+func TestTypedToolHandlerWithComplexObjects(t *testing.T) {
+	// Define a complex test struct with nested objects
+	type Address struct {
+		Street  string `json:"street"`
+		City    string `json:"city"`
+		Country string `json:"country"`
+		ZipCode string `json:"zip_code"`
+	}
+
+	type UserPreferences struct {
+		Theme       string   `json:"theme"`
+		Timezone    string   `json:"timezone"`
+		Newsletters []string `json:"newsletters"`
+	}
+
+	type UserProfile struct {
+		Name        string         `json:"name"`
+		Email       string         `json:"email"`
+		Age         int            `json:"age"`
+		IsVerified  bool           `json:"is_verified"`
+		Address     Address        `json:"address"`
+		Preferences UserPreferences `json:"preferences"`
+		Tags        []string       `json:"tags"`
+	}
+
+	// Create a typed handler function
+	typedHandler := func(ctx context.Context, request CallToolRequest, profile UserProfile) (*CallToolResult, error) {
+		// Validate required fields
+		if profile.Name == "" {
+			return NewToolResultError("name is required"), nil
+		}
+		if profile.Email == "" {
+			return NewToolResultError("email is required"), nil
+		}
+
+		// Build a response that includes nested object data
+		response := fmt.Sprintf("User: %s (%s)", profile.Name, profile.Email)
+		
+		if profile.Age > 0 {
+			response += fmt.Sprintf(", Age: %d", profile.Age)
+		}
+		
+		if profile.IsVerified {
+			response += ", Verified: Yes"
+		} else {
+			response += ", Verified: No"
+		}
+		
+		// Include address information if available
+		if profile.Address.City != "" && profile.Address.Country != "" {
+			response += fmt.Sprintf(", Location: %s, %s", profile.Address.City, profile.Address.Country)
+		}
+		
+		// Include preferences if available
+		if profile.Preferences.Theme != "" {
+			response += fmt.Sprintf(", Theme: %s", profile.Preferences.Theme)
+		}
+		
+		if len(profile.Preferences.Newsletters) > 0 {
+			response += fmt.Sprintf(", Subscribed to %d newsletters", len(profile.Preferences.Newsletters))
+		}
+		
+		if len(profile.Tags) > 0 {
+			response += fmt.Sprintf(", Tags: %v", profile.Tags)
+		}
+		
+		return NewToolResultText(response), nil
+	}
+
+	// Create a wrapped handler
+	wrappedHandler := NewTypedToolHandler(typedHandler)
+
+	// Test with complete complex object
+	req := CallToolRequest{}
+	req.Params.Name = "user_profile"
+	req.Params.Arguments = map[string]any{
+		"name":        "John Doe",
+		"email":       "john@example.com",
+		"age":         35,
+		"is_verified": true,
+		"address": map[string]any{
+			"street":   "123 Main St",
+			"city":     "San Francisco",
+			"country":  "USA",
+			"zip_code": "94105",
+		},
+		"preferences": map[string]any{
+			"theme":       "dark",
+			"timezone":    "America/Los_Angeles",
+			"newsletters": []string{"weekly", "product_updates"},
+		},
+		"tags": []string{"premium", "early_adopter"},
+	}
+
+	// Call the wrapped handler
+	result, err := wrappedHandler(context.Background(), req)
+
+	// Verify results
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.Contains(t, result.Content[0].(TextContent).Text, "John Doe")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "San Francisco, USA")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Theme: dark")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Subscribed to 2 newsletters")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Tags: [premium early_adopter]")
+
+	// Test with partial data (missing some nested fields)
+	req.Params.Arguments = map[string]any{
+		"name":        "Jane Smith",
+		"email":       "jane@example.com",
+		"age":         28,
+		"is_verified": false,
+		"address": map[string]any{
+			"city":    "London",
+			"country": "UK",
+		},
+		"preferences": map[string]any{
+			"theme": "light",
+		},
+	}
+
+	result, err = wrappedHandler(context.Background(), req)
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Jane Smith")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "London, UK")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Theme: light")
+	assert.NotContains(t, result.Content[0].(TextContent).Text, "newsletters")
+
+	// Test with JSON string input (simulating raw JSON from client)
+	jsonInput := `{
+		"name": "Bob Johnson",
+		"email": "bob@example.com",
+		"age": 42,
+		"is_verified": true,
+		"address": {
+			"street": "456 Park Ave",
+			"city": "New York",
+			"country": "USA",
+			"zip_code": "10022"
+		},
+		"preferences": {
+			"theme": "system",
+			"timezone": "America/New_York",
+			"newsletters": ["monthly"]
+		},
+		"tags": ["business"]
+	}`
+
+	req.Params.Arguments = json.RawMessage(jsonInput)
+	result, err = wrappedHandler(context.Background(), req)
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Bob Johnson")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "New York, USA")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Theme: system")
+	assert.Contains(t, result.Content[0].(TextContent).Text, "Subscribed to 1 newsletters")
+}
\ No newline at end of file
diff --git a/mcptest/mcptest_test.go b/mcptest/mcptest_test.go
index 3fa8af5..b71b93e 100644
--- a/mcptest/mcptest_test.go
+++ b/mcptest/mcptest_test.go
@@ -52,7 +52,7 @@ func TestServer(t *testing.T) {
 
 func helloWorldHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 	// Extract name from request arguments
-	name, ok := request.Params.Arguments["name"].(string)
+	name, ok := request.GetArguments()["name"].(string)
 	if !ok {
 		name = "World"
 	}