diff --git a/errors/gerror/gerror.go b/errors/gerror/gerror.go
index 95a2494a2..ee3e6c746 100644
--- a/errors/gerror/gerror.go
+++ b/errors/gerror/gerror.go
@@ -222,6 +222,9 @@ func Code(err error) gcode.Code {
 	if e, ok := err.(iNext); ok {
 		return Code(e.Next())
 	}
+	if e, ok := err.(iUnwrap); ok {
+		return Code(e.Unwrap())
+	}
 	return gcode.CodeNil
 }
 
@@ -236,6 +239,9 @@ func Cause(err error) error {
 	if e, ok := err.(iNext); ok {
 		return Cause(e.Next())
 	}
+	if e, ok := err.(iUnwrap); ok {
+		return Cause(e.Unwrap())
+	}
 	return err
 }
 
diff --git a/errors/gerror/gerror_interface.go b/errors/gerror/gerror_interface.go
index 317f951dc..f4b5a32d7 100644
--- a/errors/gerror/gerror_interface.go
+++ b/errors/gerror/gerror_interface.go
@@ -49,3 +49,9 @@ type iNext interface {
 	Error() string
 	Next() error
 }
+
+// iUnwrap is the interface for Unwrap feature.
+type iUnwrap interface {
+	Error() string
+	Unwrap() error
+}
diff --git a/errors/gerror/gerror_z_example_test.go b/errors/gerror/gerror_z_example_test.go
index e43338e9c..998b54237 100644
--- a/errors/gerror/gerror_z_example_test.go
+++ b/errors/gerror/gerror_z_example_test.go
@@ -55,3 +55,30 @@ func ExampleWrapCodef() {
 	// It's Custom Error: permission denied
 	// 10000
 }
+
+func ExampleEqual() {
+	err1 := errors.New("permission denied")
+	err2 := gerror.New("permission denied")
+	err3 := gerror.NewCode(gcode.CodeNotAuthorized, "permission denied")
+	fmt.Println(gerror.Equal(err1, err2))
+	fmt.Println(gerror.Equal(err2, err3))
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleIs() {
+	err1 := errors.New("permission denied")
+	err2 := gerror.Wrap(err1, "operation failed")
+	fmt.Println(gerror.Is(err1, err1))
+	fmt.Println(gerror.Is(err2, err2))
+	fmt.Println(gerror.Is(err2, err1))
+	fmt.Println(gerror.Is(err1, err2))
+
+	// Output:
+	// false
+	// true
+	// true
+	// false
+}