diff --git a/examples/main.go b/examples/main.go
index 63f0dd2..2b1c1e9 100644
--- a/examples/main.go
+++ b/examples/main.go
@@ -22,13 +22,13 @@ func main() {
 	rules := validator.Rules(
 		validator.RuleFor(
 			user.Firstname,
-			validator.Required(),
+			validator.Required[string](),
 			validator.Min(4),
-			Custom(),
+			Custom[string](),
 		).WithName("firstname"),
 		validator.RuleFor(
 			user.Lastname,
-			validator.Required(),
+			validator.Required[string](),
 			validator.Min(3),
 		).WithName("lastname"),
 		validator.RuleFor(user.Age, validator.Min(0)),
@@ -45,7 +45,7 @@ func Custom[T any]() *validator.RuleConfig[T] {
 			return fmt.Sprintf("'%s' must equal 'jane'", r.Value)
 		},
 		ValidateFunc: func(r validator.RuleConfig[T]) bool {
-			val, ok := r.Value.(string)
+			val, ok := any(r.Value).(string)
 			if !ok {
 				return false
 			}
diff --git a/rules.go b/rules.go
index 2335a3a..b2e2661 100644
--- a/rules.go
+++ b/rules.go
@@ -41,13 +41,16 @@ func Must[T any](predicate func() bool) *RuleConfig[T] {
 	}
 }
 
-func Required[T string]() *RuleConfig[T] {
+func Required[T any]() *RuleConfig[T] {
 	return &RuleConfig[T]{
 		MessageFunc: func(r RuleConfig[T]) string {
 			return "Required"
 		},
 		ValidateFunc: func(r RuleConfig[T]) bool {
-			return len(r.Value) > 0
+			// if needed
+			// if val is string, check against nil, empty string
+			// if val is int, check against nil, 0 etc.
+			return any(r.Value) != nil
 		},
 	}
 }
diff --git a/test-01/main.go b/test-01/main.go
index d960758..fa96519 100644
--- a/test-01/main.go
+++ b/test-01/main.go
@@ -7,14 +7,14 @@ type Validator struct {
 	Errors []error
 }
 
-type Rule func(*Validator) *Validator
+type Rule[T any] func(*T) *T
 
 type StringValidator struct {
-	Validator
+	*Validator
 }
 
-func NewStringValidator(value string, opts ...Rule) *StringValidator {
-	v := &StringValidator{Validator{value: value}}
+func NewStringValidator(value string, opts ...StringRule) *StringValidator {
+	v := &StringValidator{&Validator{value: value}}
 	for _, opt := range opts {
 		opt(v)
 	}
@@ -22,8 +22,14 @@ func NewStringValidator(value string, opts ...Rule) *StringValidator {
 	return v
 }
 
-func NewIntValidator[T any](value T, opts ...Rule) *Validator {
-	v := &Validator{value: value}
+type IntRule func(*IntValidator) *IntValidator
+
+type IntValidator struct {
+	*Validator
+}
+
+func NewIntValidator(value int, opts ...IntRule) *IntValidator {
+	v := &IntValidator{&Validator{value: value}}
 	for _, opt := range opts {
 		opt(v)
 	}
@@ -31,17 +37,19 @@ func NewIntValidator[T any](value T, opts ...Rule) *Validator {
 	return v
 }
 
-func Min(min int) Rule {
+func Min(min int) StringRule {
 	return func(v *StringValidator) *StringValidator {
-		if len(v.value) < min {
-			v.Errors = append(v.Errors, fmt.Errorf("min length not met."))
+		if str, ok := any(v.value).(string); ok {
+			if len(str) < min {
+				v.Errors = append(v.Errors, fmt.Errorf("min length not met."))
+			}
 		}
 		return v
 	}
 }
 
-func Test() Rule {
-	return func(v *Validator) *Validator {
+func Required[T any]() Rule[T] {
+	return func(v *T) *T {
 		if str, ok := any(v.value).(string); ok {
 			if str != "test" {
 				v.Errors = append(v.Errors, fmt.Errorf("value does not equal 'test'"))
@@ -52,7 +60,7 @@ func Test() Rule {
 }
 
 func main() {
-	v := NewStringValidator("john", Test(), Min(5))
+	v := NewStringValidator("john", Required[StringValidator](), Min(5))
 	// NewValidator(10, Min(5), Test[string]())
 
 	fmt.Printf("error: %v\n", v.Errors)
diff --git a/test-02/main.go b/test-02/main.go
new file mode 100644
index 0000000..60a56b1
--- /dev/null
+++ b/test-02/main.go
@@ -0,0 +1,95 @@
+// zod
+
+package main
+
+import "fmt"
+
+type Schema struct{}
+
+func NewSchema() *Schema {
+	s := &Schema{}
+
+	return s
+}
+
+// string
+type StringSchema struct {
+	checks []func(string) bool
+}
+
+func (s *Schema) String() *StringSchema {
+	v := &StringSchema{}
+
+	return v
+}
+
+func (s *StringSchema) Min(min int) *StringSchema {
+	s.checks = append(s.checks, func(value string) bool {
+		if len(value) < min {
+			return false
+		}
+		return true
+	})
+
+	return s
+}
+
+func (s *StringSchema) Parse(value any) bool {
+	val, ok := value.(string)
+	if !ok {
+		return false
+	}
+
+	for _, check := range s.checks {
+		if !check(val) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// int
+type IntSchema struct {
+	checks []func(int) bool
+}
+
+func (s *Schema) Int() *IntSchema {
+	v := &IntSchema{}
+
+	return v
+}
+
+func (s *IntSchema) LessThan(min int) *IntSchema {
+	s.checks = append(s.checks, func(value int) bool {
+		if value < min {
+			return true
+		}
+		return false
+	})
+
+	return s
+}
+
+func (s *IntSchema) Parse(value any) bool {
+	val, ok := value.(int)
+	if !ok {
+		return false
+	}
+
+	for _, check := range s.checks {
+		if !check(val) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func main() {
+	v := NewSchema().String().Min(4).Parse("john")
+	s := NewSchema().Int().LessThan(4).Parse(1)
+
+	fmt.Printf("(1) is valid: %t\n", v)
+	fmt.Printf("(2) is valid: %t\n", s)
+}
diff --git a/test/main.go b/test/main.go
index 72b6428..e59c166 100644
--- a/test/main.go
+++ b/test/main.go
@@ -1,3 +1,4 @@
+// generics (simple)
 package main
 
 import "fmt"
diff --git a/validator_test.go b/validator_test.go
index 5b5d2c3..6e2d853 100644
--- a/validator_test.go
+++ b/validator_test.go
@@ -115,7 +115,7 @@ func Test_GreaterThanValid_ReturnsTrue(t *testing.T) {
 
 	rule := validator.RuleFor(
 		user.Age,
-		validator.Required(),
+		validator.Required[int](),
 		validator.GreaterThan(17),
 	)