diff --git a/internal/modules/inventory/product-warehouses/controllers/product_warehouse.controller.go b/internal/modules/inventory/product-warehouses/controllers/product_warehouse.controller.go
index 5737e9f0..5fd060dd 100644
--- a/internal/modules/inventory/product-warehouses/controllers/product_warehouse.controller.go
+++ b/internal/modules/inventory/product-warehouses/controllers/product_warehouse.controller.go
@@ -29,6 +29,7 @@ func (u *ProductWarehouseController) GetAll(c *fiber.Ctx) error {
 		Limit:           c.QueryInt("limit", 10),
 		ProductId:       uint(c.QueryInt("product_id", 0)),
 		WarehouseId:     uint(c.QueryInt("warehouse_id", 0)),
+		LocationId:      uint(c.QueryInt("location_id", 0)),
 		Flags:           c.Query("flags", ""),
 		KandangId:       uint(c.QueryInt("kandang_id", 0)),
 		TransferContext: c.Query(utils.TransferContextKey, ""),
diff --git a/internal/modules/inventory/product-warehouses/controllers/product_warehouse.controller_test.go b/internal/modules/inventory/product-warehouses/controllers/product_warehouse.controller_test.go
new file mode 100644
index 00000000..93a015ca
--- /dev/null
+++ b/internal/modules/inventory/product-warehouses/controllers/product_warehouse.controller_test.go
@@ -0,0 +1,64 @@
+package controller
+
+import (
+	"errors"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-playground/validator/v10"
+	"github.com/gofiber/fiber/v2"
+	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
+	service "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/product-warehouses/services"
+	validation "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/product-warehouses/validations"
+	"gorm.io/gorm"
+)
+
+type stubProductWarehouseService struct {
+	lastQuery *validation.Query
+}
+
+func (s *stubProductWarehouseService) GetAll(_ *fiber.Ctx, params *validation.Query) ([]entity.ProductWarehouse, int64, error) {
+	s.lastQuery = params
+	return []entity.ProductWarehouse{}, 0, nil
+}
+
+func (s *stubProductWarehouseService) GetOne(_ *fiber.Ctx, _ uint) (*entity.ProductWarehouse, error) {
+	return nil, gorm.ErrRecordNotFound
+}
+
+var _ service.ProductWarehouseService = (*stubProductWarehouseService)(nil)
+
+func TestGetAllParsesLocationID(t *testing.T) {
+	app := fiber.New()
+	stub := &stubProductWarehouseService{}
+	ctrl := NewProductWarehouseController(stub)
+	app.Get("/product-warehouses", ctrl.GetAll)
+
+	req := httptest.NewRequest("GET", "/product-warehouses?location_id=16&kandang_id=59&limit=25", nil)
+	resp, err := app.Test(req)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if resp.StatusCode != fiber.StatusOK {
+		t.Fatalf("expected status 200, got %d", resp.StatusCode)
+	}
+	if stub.lastQuery == nil {
+		t.Fatalf("expected service to receive query")
+	}
+	if stub.lastQuery.LocationId != 16 {
+		t.Fatalf("expected location_id 16, got %d", stub.lastQuery.LocationId)
+	}
+	if stub.lastQuery.KandangId != 59 {
+		t.Fatalf("expected kandang_id 59, got %d", stub.lastQuery.KandangId)
+	}
+	if stub.lastQuery.Limit != 25 {
+		t.Fatalf("expected limit 25, got %d", stub.lastQuery.Limit)
+	}
+}
+
+func TestStubImplementsServiceContract(t *testing.T) {
+	validate := validator.New()
+	if validate == nil {
+		t.Fatal(errors.New("validator should not be nil"))
+	}
+}
diff --git a/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository.go b/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository.go
index 87d114c9..2659533d 100644
--- a/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository.go
+++ b/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository.go
@@ -7,6 +7,7 @@ import (
 
 	"gitlab.com/mbugroup/lti-api.git/internal/common/repository"
 	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
+	"gitlab.com/mbugroup/lti-api.git/internal/utils"
 	"gorm.io/gorm"
 )
 
@@ -164,10 +165,42 @@ func (r *ProductWarehouseRepositoryImpl) ApplyFlagsFilter(db *gorm.DB, flags []s
 		return db
 	}
 
-	return db.
+	fallbackCategoryCodes := utils.LegacyProductCategoryCodesForFlags(flags)
+
+	db = db.
 		Joins("JOIN products p_flag ON p_flag.id = product_warehouses.product_id").
-		Joins("JOIN flags f_flag ON f_flag.flagable_id = p_flag.id AND f_flag.flagable_type = ?", "products").
-		Where("f_flag.name IN ?", flags).
+		Joins("LEFT JOIN product_categories pc_flag ON pc_flag.id = p_flag.product_category_id")
+
+	actualFlagFilter := `
+		EXISTS (
+			SELECT 1
+			FROM flags f_flag
+			WHERE f_flag.flagable_id = p_flag.id
+			  AND f_flag.flagable_type = ?
+			  AND f_flag.name IN ?
+		)
+	`
+
+	if len(fallbackCategoryCodes) == 0 {
+		return db.Where(actualFlagFilter, entity.FlagableTypeProduct, flags).Distinct()
+	}
+
+	return db.
+		Where(
+			`(`+actualFlagFilter+`) OR (
+				NOT EXISTS (
+					SELECT 1
+					FROM flags f_any
+					WHERE f_any.flagable_id = p_flag.id
+					  AND f_any.flagable_type = ?
+				)
+				AND pc_flag.code IN ?
+			)`,
+			entity.FlagableTypeProduct,
+			flags,
+			entity.FlagableTypeProduct,
+			fallbackCategoryCodes,
+		).
 		Distinct()
 }
 
diff --git a/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository_test.go b/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository_test.go
index a224404b..3f810e53 100644
--- a/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository_test.go
+++ b/internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository_test.go
@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/glebarez/sqlite"
+	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
 	"gorm.io/gorm"
 )
 
@@ -115,3 +116,75 @@ func insertProductWarehouseTestFixtures(t *testing.T, db *gorm.DB) {
 		}
 	}
 }
+
+func TestApplyFlagsFilterIncludesLegacyCategoryFallback(t *testing.T) {
+	db := setupProductWarehouseFlagFilterTestDB(t)
+	repo := NewProductWarehouseRepository(db)
+	ctx := context.Background()
+
+	var ids []uint
+	err := repo.ApplyFlagsFilter(
+		db.WithContext(ctx).Model(&entity.ProductWarehouse{}),
+		[]string{"PAKAN"},
+	).Order("product_warehouses.id").Pluck("product_warehouses.id", &ids).Error
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if len(ids) != 2 || ids[0] != 1 || ids[1] != 2 {
+		t.Fatalf("expected flagged and legacy RAW rows to match, got %v", ids)
+	}
+}
+
+func TestApplyFlagsFilterDoesNotFallbackWhenProductAlreadyHasDifferentFlags(t *testing.T) {
+	db := setupProductWarehouseFlagFilterTestDB(t)
+	repo := NewProductWarehouseRepository(db)
+	ctx := context.Background()
+
+	var ids []uint
+	err := repo.ApplyFlagsFilter(
+		db.WithContext(ctx).Model(&entity.ProductWarehouse{}),
+		[]string{"PAKAN"},
+	).Where("product_warehouses.id = ?", 3).Pluck("product_warehouses.id", &ids).Error
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if len(ids) != 0 {
+		t.Fatalf("expected OVK-flagged product not to match PAKAN fallback, got %v", ids)
+	}
+}
+
+func setupProductWarehouseFlagFilterTestDB(t *testing.T) *gorm.DB {
+	t.Helper()
+
+	db, err := gorm.Open(sqlite.Open("file:"+t.Name()+"?mode=memory&cache=private"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("failed opening sqlite db: %v", err)
+	}
+
+	statements := []string{
+		`CREATE TABLE product_categories (id INTEGER PRIMARY KEY, code TEXT NOT NULL)`,
+		`CREATE TABLE products (id INTEGER PRIMARY KEY, product_category_id INTEGER NOT NULL)`,
+		`CREATE TABLE flags (id INTEGER PRIMARY KEY, flagable_id INTEGER NOT NULL, flagable_type TEXT NOT NULL, name TEXT NOT NULL)`,
+		`CREATE TABLE product_warehouses (id INTEGER PRIMARY KEY, product_id INTEGER NOT NULL, warehouse_id INTEGER NOT NULL, project_flock_kandang_id INTEGER NULL, qty NUMERIC(15,3) NOT NULL DEFAULT 0)`,
+		`INSERT INTO product_categories (id, code) VALUES (1, 'STR'), (2, 'RAW'), (3, 'OBT')`,
+		`INSERT INTO products (id, product_category_id) VALUES (10, 1), (20, 2), (30, 2), (40, 3)`,
+		`INSERT INTO flags (id, flagable_id, flagable_type, name) VALUES
+			(1, 10, 'products', 'PAKAN'),
+			(2, 10, 'products', 'STARTER'),
+			(3, 40, 'products', 'OVK'),
+			(4, 40, 'products', 'OBAT')`,
+		`INSERT INTO product_warehouses (id, product_id, warehouse_id, project_flock_kandang_id, qty) VALUES
+			(1, 10, 1, NULL, 10),
+			(2, 20, 1, NULL, 20),
+			(3, 40, 1, NULL, 30)`,
+	}
+	for _, stmt := range statements {
+		if err := db.Exec(stmt).Error; err != nil {
+			t.Fatalf("failed preparing schema: %v", err)
+		}
+	}
+
+	return db
+}
diff --git a/internal/modules/purchases/services/fifo_stock_v2_helper.go b/internal/modules/purchases/services/fifo_stock_v2_helper.go
index e0b619a9..da7770cc 100644
--- a/internal/modules/purchases/services/fifo_stock_v2_helper.go
+++ b/internal/modules/purchases/services/fifo_stock_v2_helper.go
@@ -2,12 +2,14 @@ package service
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"strings"
 	"time"
 
 	commonSvc "gitlab.com/mbugroup/lti-api.git/internal/common/service"
 	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
+	"gitlab.com/mbugroup/lti-api.git/internal/utils"
 	"gorm.io/gorm"
 )
 
@@ -76,11 +78,53 @@ func resolvePurchaseFlagGroupByProductWarehouse(ctx context.Context, tx *gorm.DB
 		Order("rr.id ASC").
 		Limit(1).
 		Take(&selected).Error
+	if err == nil {
+		return strings.TrimSpace(selected.FlagGroupCode), nil
+	}
+	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
+		return "", err
+	}
+
+	type categoryRow struct {
+		CategoryCode string `gorm:"column:category_code"`
+	}
+
+	var category categoryRow
+	err = tx.WithContext(ctx).
+		Table("product_warehouses pw").
+		Select("pc.code AS category_code").
+		Joins("JOIN products p ON p.id = pw.product_id").
+		Joins("JOIN product_categories pc ON pc.id = p.product_category_id").
+		Where("pw.id = ?", productWarehouseID).
+		Limit(1).
+		Take(&category).Error
 	if err != nil {
 		return "", err
 	}
 
-	return strings.TrimSpace(selected.FlagGroupCode), nil
+	flagGroupCode := utils.LegacyFlagGroupCodeByProductCategoryCode(category.CategoryCode)
+	if flagGroupCode == "" {
+		return "", gorm.ErrRecordNotFound
+	}
+
+	var matched int64
+	err = tx.WithContext(ctx).
+		Table("fifo_stock_v2_route_rules rr").
+		Joins("JOIN fifo_stock_v2_flag_groups fg ON fg.code = rr.flag_group_code AND fg.is_active = TRUE").
+		Where("rr.is_active = TRUE").
+		Where("rr.lane = ?", purchaseStockableLane).
+		Where("rr.function_code = ?", purchaseInFunctionCode).
+		Where("rr.source_table = ?", purchaseSourceTable).
+		Where("rr.flag_group_code = ?", flagGroupCode).
+		Count(&matched).Error
+	if err != nil {
+		return "", err
+	}
+	if matched == 0 {
+		return "", gorm.ErrRecordNotFound
+	}
+
+	return flagGroupCode, nil
 }
 
 func assignEarliestAsOf(m map[uint]time.Time, productWarehouseID uint, asOf time.Time) {
diff --git a/internal/modules/purchases/services/fifo_stock_v2_helper_test.go b/internal/modules/purchases/services/fifo_stock_v2_helper_test.go
new file mode 100644
index 00000000..dbc29110
--- /dev/null
+++ b/internal/modules/purchases/services/fifo_stock_v2_helper_test.go
@@ -0,0 +1,80 @@
+package service
+
+import (
+	"context"
+	"testing"
+
+	"github.com/glebarez/sqlite"
+	"gorm.io/gorm"
+)
+
+func TestResolvePurchaseFlagGroupByProductWarehouseFallsBackToProductCategory(t *testing.T) {
+	db := setupPurchaseFifoHelperTestDB(t)
+	ctx := context.Background()
+
+	flagGroupCode, err := resolvePurchaseFlagGroupByProductWarehouse(ctx, db, 1115)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if flagGroupCode != "PAKAN" {
+		t.Fatalf("expected PAKAN, got %s", flagGroupCode)
+	}
+}
+
+func TestResolvePurchaseFlagGroupByProductWarehouseUsesProductFlagsWhenPresent(t *testing.T) {
+	db := setupPurchaseFifoHelperTestDB(t)
+	ctx := context.Background()
+
+	flagGroupCode, err := resolvePurchaseFlagGroupByProductWarehouse(ctx, db, 2222)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if flagGroupCode != "OVK" {
+		t.Fatalf("expected OVK, got %s", flagGroupCode)
+	}
+}
+
+func setupPurchaseFifoHelperTestDB(t *testing.T) *gorm.DB {
+	t.Helper()
+
+	db, err := gorm.Open(sqlite.Open("file:"+t.Name()+"?mode=memory&cache=private"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("failed opening sqlite db: %v", err)
+	}
+
+	statements := []string{
+		`CREATE TABLE fifo_stock_v2_flag_groups (code TEXT PRIMARY KEY, is_active BOOLEAN NOT NULL)`,
+		`CREATE TABLE fifo_stock_v2_flag_members (flag_name TEXT NOT NULL, flag_group_code TEXT NOT NULL, is_active BOOLEAN NOT NULL)`,
+		`CREATE TABLE fifo_stock_v2_route_rules (
+			id INTEGER PRIMARY KEY,
+			flag_group_code TEXT NOT NULL,
+			lane TEXT NOT NULL,
+			function_code TEXT NOT NULL,
+			source_table TEXT NOT NULL,
+			is_active BOOLEAN NOT NULL
+		)`,
+		`CREATE TABLE product_categories (id INTEGER PRIMARY KEY, code TEXT NOT NULL)`,
+		`CREATE TABLE products (id INTEGER PRIMARY KEY, product_category_id INTEGER NOT NULL)`,
+		`CREATE TABLE flags (id INTEGER PRIMARY KEY, flagable_id INTEGER NOT NULL, flagable_type TEXT NOT NULL, name TEXT NOT NULL)`,
+		`CREATE TABLE product_warehouses (id INTEGER PRIMARY KEY, product_id INTEGER NOT NULL)`,
+		`INSERT INTO fifo_stock_v2_flag_groups (code, is_active) VALUES ('PAKAN', TRUE), ('OVK', TRUE)`,
+		`INSERT INTO fifo_stock_v2_flag_members (flag_name, flag_group_code, is_active) VALUES ('PAKAN', 'PAKAN', TRUE), ('OVK', 'OVK', TRUE), ('OBAT', 'OVK', TRUE)`,
+		`INSERT INTO fifo_stock_v2_route_rules (id, flag_group_code, lane, function_code, source_table, is_active) VALUES
+			(1, 'PAKAN', 'STOCKABLE', 'PURCHASE_IN', 'purchase_items', TRUE),
+			(2, 'OVK', 'STOCKABLE', 'PURCHASE_IN', 'purchase_items', TRUE)`,
+		`INSERT INTO product_categories (id, code) VALUES (1, 'RAW'), (2, 'OBT')`,
+		`INSERT INTO products (id, product_category_id) VALUES (37, 1), (112, 2)`,
+		`INSERT INTO flags (id, flagable_id, flagable_type, name) VALUES
+			(1, 112, 'products', 'OVK'),
+			(2, 112, 'products', 'OBAT')`,
+		`INSERT INTO product_warehouses (id, product_id) VALUES (1115, 37), (2222, 112)`,
+	}
+
+	for _, stmt := range statements {
+		if err := db.Exec(stmt).Error; err != nil {
+			t.Fatalf("failed preparing schema: %v", err)
+		}
+	}
+
+	return db
+}
diff --git a/internal/utils/constant.go b/internal/utils/constant.go
index c263180b..dfe4ef6e 100644
--- a/internal/utils/constant.go
+++ b/internal/utils/constant.go
@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"slices"
 	"strings"
 
 	approvalutils "gitlab.com/mbugroup/lti-api.git/internal/utils/approvals"
@@ -129,10 +130,23 @@ var productSubFlagToFlag = func() map[FlagType]FlagType {
 }()
 
 var productAllowWithoutSubFlagByFlag = map[FlagType]bool{
-	FlagAyam:        true,
-	FlagPakan:       false,
-	FlagOVK:         false,
-	FlagTelur:       false,
+	FlagAyam:  true,
+	FlagPakan: false,
+	FlagOVK:   false,
+	FlagTelur: false,
+}
+
+var legacyProductCategoryFlagsByCode = map[string][]FlagType{
+	"DOC": {FlagAyam, FlagDOC},
+	"PLT": {FlagAyam, FlagPullet},
+	"EGG": {FlagTelur},
+	"RAW": {FlagPakan},
+	"PST": {FlagPakan, FlagPreStarter},
+	"STR": {FlagPakan, FlagStarter},
+	"FSR": {FlagPakan, FlagFinisher},
+	"OBT": {FlagOVK, FlagObat},
+	"VTM": {FlagOVK, FlagVitamin},
+	"KMA": {FlagOVK, FlagKimia},
 }
 
 var legacyFlagTypeAliases = map[FlagType]FlagType{
@@ -228,6 +242,52 @@ func ProductFlagAllowWithoutSubFlag(flag FlagType) bool {
 	return allow
 }
 
+func LegacyProductCategoryCodesForFlags(flags []string) []string {
+	if len(flags) == 0 {
+		return nil
+	}
+
+	requested := make(map[FlagType]struct{}, len(flags))
+	for _, flag := range flags {
+		canonical := CanonicalFlagType(flag)
+		if canonical == "" {
+			continue
+		}
+		requested[canonical] = struct{}{}
+	}
+	if len(requested) == 0 {
+		return nil
+	}
+
+	codes := make([]string, 0, len(legacyProductCategoryFlagsByCode))
+	for code, supportedFlags := range legacyProductCategoryFlagsByCode {
+		for _, supportedFlag := range supportedFlags {
+			if _, ok := requested[canonicalizeFlagType(supportedFlag)]; ok {
+				codes = append(codes, code)
+				break
+			}
+		}
+	}
+
+	slices.Sort(codes)
+	return codes
+}
+
+func LegacyFlagGroupCodeByProductCategoryCode(code string) string {
+	switch strings.ToUpper(strings.TrimSpace(code)) {
+	case "DOC", "PLT":
+		return "AYAM"
+	case "EGG":
+		return "TELUR"
+	case "RAW", "PST", "STR", "FSR":
+		return "PAKAN"
+	case "OBT", "VTM", "KMA":
+		return "OVK"
+	default:
+		return ""
+	}
+}
+
 func IsProductMainFlag(flag FlagType) bool {
 	canonical := canonicalizeFlagType(flag)
 	for _, f := range productMainFlags {