diff --git a/common.go b/common.go
index 32efcf1..84264c1 100644
--- a/common.go
+++ b/common.go
@@ -175,7 +175,17 @@ func isZero(v interface{}) bool {
 // Parse path parameters
 func parsePathParams(c *fiber.Ctx, input interface{}) error {
 	inputValue := reflect.ValueOf(input).Elem()
-	inputType := reflect.TypeOf(input).Elem()
+	inputType := dereferenceType(reflect.TypeOf(input).Elem())
+
+	if inputType.Kind() != reflect.Struct {
+		return nil
+	}
+	if inputValue.Kind() == reflect.Ptr {
+		if inputValue.IsNil() {
+			return nil
+		}
+		inputValue = inputValue.Elem()
+	}
 
 	for i := 0; i < inputType.NumField(); i++ {
 		field := inputType.Field(i)
@@ -196,7 +206,17 @@ func parsePathParams(c *fiber.Ctx, input interface{}) error {
 // Parse query parameters
 func parseQueryParams(c *fiber.Ctx, input interface{}) error {
 	inputValue := reflect.ValueOf(input).Elem()
-	inputType := reflect.TypeOf(input).Elem()
+	inputType := dereferenceType(reflect.TypeOf(input).Elem())
+
+	if inputType.Kind() != reflect.Struct {
+		return nil
+	}
+	if inputValue.Kind() == reflect.Ptr {
+		if inputValue.IsNil() {
+			return nil
+		}
+		inputValue = inputValue.Elem()
+	}
 
 	for i := 0; i < inputType.NumField(); i++ {
 		field := inputType.Field(i)
@@ -219,7 +239,17 @@ func parseQueryParams(c *fiber.Ctx, input interface{}) error {
 // Parse header parameters
 func parseHeaderParams(c *fiber.Ctx, input interface{}) error {
 	inputValue := reflect.ValueOf(input).Elem()
-	inputType := reflect.TypeOf(input).Elem()
+	inputType := dereferenceType(reflect.TypeOf(input).Elem())
+
+	if inputType.Kind() != reflect.Struct {
+		return nil
+	}
+	if inputValue.Kind() == reflect.Ptr {
+		if inputValue.IsNil() {
+			return nil
+		}
+		inputValue = inputValue.Elem()
+	}
 
 	for i := 0; i < inputType.NumField(); i++ {
 		field := inputType.Field(i)
diff --git a/fiberoapi.go b/fiberoapi.go
index c50c03f..dfa9e42 100644
--- a/fiberoapi.go
+++ b/fiberoapi.go
@@ -283,8 +283,7 @@ func (o *OApiApp) GenerateOpenAPISpec() map[string]interface{} {
 
 				var schemaRef map[string]interface{}
 
-				// For map types, use inline schema instead of reference
-				if inputType.Kind() == reflect.Map {
+				if shouldInlineOperationSchema(inputType) {
 					schemaRef = generateSchema(inputType)
 				} else {
 					inputSchemaName := getTypeName(inputType)
@@ -313,8 +312,7 @@ func (o *OApiApp) GenerateOpenAPISpec() map[string]interface{} {
 
 			var schemaRef map[string]interface{}
 
-			// For map types, use inline schema instead of reference
-			if outputType.Kind() == reflect.Map {
+			if shouldInlineOperationSchema(outputType) {
 				schemaRef = generateSchema(outputType)
 			} else {
 				outputSchemaName := getTypeName(outputType)
@@ -335,15 +333,22 @@ func (o *OApiApp) GenerateOpenAPISpec() map[string]interface{} {
 
 		// Error response (400/500)
 		if op.ErrorType != nil && !isEmptyStruct(op.ErrorType) {
-			errorSchemaName := getTypeName(op.ErrorType)
+			errorType := dereferenceType(op.ErrorType)
+
+			var schemaRef map[string]interface{}
+			if shouldInlineOperationSchema(errorType) {
+				schemaRef = generateSchema(errorType)
+			} else {
+				schemaRef = map[string]interface{}{
+					"$ref": "#/components/schemas/" + getTypeName(errorType),
+				}
+			}
 
 			responses["400"] = map[string]interface{}{
 				"description": "Validation error",
 				"content": map[string]interface{}{
 					"application/json": map[string]interface{}{
-						"schema": map[string]interface{}{
-							"$ref": "#/components/schemas/" + errorSchemaName,
-						},
+						"schema": schemaRef,
 					},
 				},
 			}
@@ -581,6 +586,33 @@ func isTimeType(t reflect.Type) bool {
 	return t != nil && t.Kind() == reflect.Struct && t.Name() == "Time" && t.PkgPath() == "time"
 }
 
+// shouldInlineOperationSchema reports whether a top-level request, response,
+// or error body schema should be inlined rather than emitted as a $ref to
+// #/components/schemas/. It mirrors the registration logic in collectAllTypes:
+// types that never end up in the components map (primitives, maps, time.Time,
+// slices of inlinable elements) must be inlined to avoid dangling $refs.
+func shouldInlineOperationSchema(t reflect.Type) bool {
+	if t == nil {
+		return false
+	}
+	t = dereferenceType(t)
+	if isTimeType(t) {
+		return true
+	}
+	switch t.Kind() {
+	case reflect.Map:
+		return true
+	case reflect.String, reflect.Bool,
+		reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+		reflect.Float32, reflect.Float64:
+		return true
+	case reflect.Slice:
+		return shouldInlineOperationSchema(t.Elem())
+	}
+	return false
+}
+
 // generateSchema generates an OpenAPI schema from a Go type
 func generateSchema(t reflect.Type) map[string]interface{} {
 	if t == nil {
diff --git a/time_type_test.go b/time_type_test.go
index d134b94..45e0b74 100644
--- a/time_type_test.go
+++ b/time_type_test.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"io"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 
@@ -119,3 +120,213 @@ func TestPointerTimeTypeRendersAsDateTimeString(t *testing.T) {
 		t.Errorf("Expected *time.Time to render as string/date-time, got %v", startedAt)
 	}
 }
+
+func TestTimeTypeAsTopLevelHandlerRuntime(t *testing.T) {
+	app := fiber.New()
+	oapi := New(app, Config{
+		EnableValidation:  false,
+		EnableOpenAPIDocs: true,
+		OpenAPIDocsPath:   "/docs",
+	})
+
+	Post(oapi, "/timestamp", func(c *fiber.Ctx, req time.Time) (time.Time, *ErrorResponse) {
+		return req, nil
+	}, OpenAPIOptions{OperationID: "echoTimestamp"})
+
+	body := strings.NewReader(`"2024-01-15T10:30:00Z"`)
+	req := httptest.NewRequest("POST", "/timestamp", body)
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := app.Test(req)
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
+	}
+	if resp.StatusCode != 200 {
+		respBody, _ := io.ReadAll(resp.Body)
+		t.Fatalf("Expected status 200, got %d: %s", resp.StatusCode, string(respBody))
+	}
+
+	respBody, _ := io.ReadAll(resp.Body)
+	var got time.Time
+	if err := json.Unmarshal(respBody, &got); err != nil {
+		t.Fatalf("Expected response to be a JSON time string, got %s (err: %v)", string(respBody), err)
+	}
+	want, _ := time.Parse(time.RFC3339, "2024-01-15T10:30:00Z")
+	if !got.Equal(want) {
+		t.Errorf("Expected echoed time %v, got %v", want, got)
+	}
+}
+
+func TestTimeTypeAsTopLevelInputAndOutput(t *testing.T) {
+	app := fiber.New()
+	oapi := New(app)
+
+	Post(oapi, "/timestamp", func(c *fiber.Ctx, req *time.Time) (*time.Time, *ErrorResponse) {
+		return req, nil
+	}, OpenAPIOptions{
+		OperationID: "echoTimestamp",
+		Tags:        []string{"timestamps"},
+	})
+
+	oapi.SetupDocs()
+
+	req := httptest.NewRequest("GET", "/openapi.json", nil)
+	resp, err := app.Test(req)
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
+	}
+
+	body, _ := io.ReadAll(resp.Body)
+	var spec map[string]interface{}
+	if err := json.Unmarshal(body, &spec); err != nil {
+		t.Fatalf("Failed to parse OpenAPI JSON: %v", err)
+	}
+
+	paths := spec["paths"].(map[string]interface{})
+	timestamp := paths["/timestamp"].(map[string]interface{})
+	post := timestamp["post"].(map[string]interface{})
+
+	reqBody := post["requestBody"].(map[string]interface{})
+	reqSchema := reqBody["content"].(map[string]interface{})["application/json"].(map[string]interface{})["schema"].(map[string]interface{})
+	if _, hasRef := reqSchema["$ref"]; hasRef {
+		t.Errorf("Expected top-level time.Time request body to be inlined, got $ref: %v", reqSchema["$ref"])
+	}
+	if reqSchema["type"] != "string" || reqSchema["format"] != "date-time" {
+		t.Errorf("Expected request body schema to be string/date-time, got %v", reqSchema)
+	}
+
+	respSchema := post["responses"].(map[string]interface{})["200"].(map[string]interface{})["content"].(map[string]interface{})["application/json"].(map[string]interface{})["schema"].(map[string]interface{})
+	if _, hasRef := respSchema["$ref"]; hasRef {
+		t.Errorf("Expected top-level time.Time response to be inlined, got $ref: %v", respSchema["$ref"])
+	}
+	if respSchema["type"] != "string" || respSchema["format"] != "date-time" {
+		t.Errorf("Expected response schema to be string/date-time, got %v", respSchema)
+	}
+
+	if schemas, ok := spec["components"].(map[string]interface{})["schemas"].(map[string]interface{}); ok {
+		if _, exists := schemas["Time"]; exists {
+			t.Errorf("time.Time should not produce a 'Time' component schema")
+		}
+	}
+}
+
+func TestPrimitiveAndSliceTopLevelSchemasInline(t *testing.T) {
+	app := fiber.New()
+	oapi := New(app, Config{
+		EnableValidation:  false,
+		EnableOpenAPIDocs: true,
+		OpenAPIDocsPath:   "/docs",
+	})
+
+	Post(oapi, "/echo-string", func(c *fiber.Ctx, req string) (string, *ErrorResponse) {
+		return req, nil
+	}, OpenAPIOptions{OperationID: "echoString"})
+
+	Post(oapi, "/echo-tags", func(c *fiber.Ctx, req []string) ([]string, *ErrorResponse) {
+		return req, nil
+	}, OpenAPIOptions{OperationID: "echoTags"})
+
+	oapi.SetupDocs()
+
+	req := httptest.NewRequest("GET", "/openapi.json", nil)
+	resp, err := app.Test(req)
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
+	}
+
+	body, _ := io.ReadAll(resp.Body)
+	var spec map[string]interface{}
+	if err := json.Unmarshal(body, &spec); err != nil {
+		t.Fatalf("Failed to parse OpenAPI JSON: %v", err)
+	}
+
+	cases := []struct {
+		path       string
+		wantType   string
+		wantItems  bool
+		wantElem   string
+		schemaName string
+	}{
+		{path: "/echo-string", wantType: "string", schemaName: "String"},
+		{path: "/echo-tags", wantType: "array", wantItems: true, wantElem: "string", schemaName: "Array_String"},
+	}
+
+	paths := spec["paths"].(map[string]interface{})
+	for _, tc := range cases {
+		op := paths[tc.path].(map[string]interface{})["post"].(map[string]interface{})
+		for _, where := range []string{"requestBody", "response"} {
+			var schema map[string]interface{}
+			if where == "requestBody" {
+				schema = op["requestBody"].(map[string]interface{})["content"].(map[string]interface{})["application/json"].(map[string]interface{})["schema"].(map[string]interface{})
+			} else {
+				schema = op["responses"].(map[string]interface{})["200"].(map[string]interface{})["content"].(map[string]interface{})["application/json"].(map[string]interface{})["schema"].(map[string]interface{})
+			}
+			if _, hasRef := schema["$ref"]; hasRef {
+				t.Errorf("%s %s: expected inline schema, got $ref %v", tc.path, where, schema["$ref"])
+				continue
+			}
+			if schema["type"] != tc.wantType {
+				t.Errorf("%s %s: expected type %q, got %v", tc.path, where, tc.wantType, schema["type"])
+			}
+			if tc.wantItems {
+				items, ok := schema["items"].(map[string]interface{})
+				if !ok {
+					t.Errorf("%s %s: expected items to be set", tc.path, where)
+					continue
+				}
+				if items["type"] != tc.wantElem {
+					t.Errorf("%s %s: expected items.type %q, got %v", tc.path, where, tc.wantElem, items["type"])
+				}
+			}
+		}
+	}
+
+	if schemas, ok := spec["components"].(map[string]interface{})["schemas"].(map[string]interface{}); ok {
+		for _, tc := range cases {
+			if _, exists := schemas[tc.schemaName]; exists {
+				t.Errorf("Did not expect %q to be registered as a component schema", tc.schemaName)
+			}
+		}
+	}
+}
+
+func TestTimeTypeAsTopLevelErrorBody(t *testing.T) {
+	app := fiber.New()
+	oapi := New(app)
+
+	Post(oapi, "/timestamp-error", func(c *fiber.Ctx, req *EmptyRequest) (*EmptyRequest, *time.Time) {
+		return &EmptyRequest{}, nil
+	}, OpenAPIOptions{
+		OperationID: "timestampError",
+		Tags:        []string{"timestamps"},
+	})
+
+	oapi.SetupDocs()
+
+	req := httptest.NewRequest("GET", "/openapi.json", nil)
+	resp, err := app.Test(req)
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
+	}
+
+	body, _ := io.ReadAll(resp.Body)
+	var spec map[string]interface{}
+	if err := json.Unmarshal(body, &spec); err != nil {
+		t.Fatalf("Failed to parse OpenAPI JSON: %v", err)
+	}
+
+	post := spec["paths"].(map[string]interface{})["/timestamp-error"].(map[string]interface{})["post"].(map[string]interface{})
+	errSchema := post["responses"].(map[string]interface{})["400"].(map[string]interface{})["content"].(map[string]interface{})["application/json"].(map[string]interface{})["schema"].(map[string]interface{})
+
+	if _, hasRef := errSchema["$ref"]; hasRef {
+		t.Errorf("Expected top-level time.Time error body to be inlined, got $ref: %v", errSchema["$ref"])
+	}
+	if errSchema["type"] != "string" || errSchema["format"] != "date-time" {
+		t.Errorf("Expected error schema to be string/date-time, got %v", errSchema)
+	}
+
+	if schemas, ok := spec["components"].(map[string]interface{})["schemas"].(map[string]interface{}); ok {
+		if _, exists := schemas["Time"]; exists {
+			t.Errorf("time.Time should not produce a 'Time' component schema")
+		}
+	}
+}