diff --git a/app/(builder)/builder/[categoryId]/[partId]/page.tsx b/app/(builder)/builder/[categoryId]/[partId]/page.tsx
index f099f1b..7bde3b4 100644
--- a/app/(builder)/builder/[categoryId]/[partId]/page.tsx
+++ b/app/(builder)/builder/[categoryId]/[partId]/page.tsx
@@ -27,7 +27,10 @@ const API_BASE_URL =
 export default function PartDetailPage() {
   const params = useParams();
   const categoryId = params.categoryId as CategoryId;
-  const partId = params.partId as string; // this is the UUID we passed in the link
+  
+  // Support URLs like /builder/lower/25969-m5-complete-lower-receiver
+  const rawPartParam = params.partId as string;
+  const partId = rawPartParam.split("-")[0]; // "25969-m5-..." -> "25969"
 
   const [product, setProduct] = useState<GunbuilderProductFromApi | null>(null);
   const [loading, setLoading] = useState(true);
diff --git a/app/(builder)/builder/[categoryId]/page.tsx b/app/(builder)/builder/[categoryId]/page.tsx
index 9ddbe7e..c0010c8 100644
--- a/app/(builder)/builder/[categoryId]/page.tsx
+++ b/app/(builder)/builder/[categoryId]/page.tsx
@@ -2,7 +2,7 @@
 
 import { useEffect, useMemo, useState } from "react";
 import Link from "next/link";
-import { useParams, useRouter } from "next/navigation";
+import { useParams, useRouter, useSearchParams } from "next/navigation";
 import { CATEGORIES } from "@/data/gunbuilderParts";
 import type { CategoryId, Part } from "@/types/gunbuilder";
 
@@ -26,6 +26,8 @@ type UiPart = Part & {
   inStock?: boolean;
 };
 
+const PLATFORMS = ["AR-15", "AR-10"];
+
 const API_BASE_URL =
   process.env.NEXT_PUBLIC_API_BASE_URL ?? "http://localhost:8080";
 
@@ -37,10 +39,18 @@ type SortOption = "relevance" | "price-asc" | "price-desc" | "brand-asc";
 type BuildState = Partial<Record<CategoryId, string>>;
 const STORAGE_KEY = "gunbuilder-build-state";
 
+// support for url id-slug
+const slugify = (str: string) =>
+  str
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, "-")
+    .replace(/(^-|-$)/g, "");
+
 export default function CategoryPage() {
   const params = useParams();
   const categoryId = params.categoryId as CategoryId;
   const router = useRouter();
+  const searchParams = useSearchParams();
 
   const [viewMode, setViewMode] = useState<ViewMode>("list");
   const [parts, setParts] = useState<UiPart[]>([]);
@@ -70,6 +80,10 @@ export default function CategoryPage() {
     }
   });
 
+  const initialPlatform =
+    (searchParams.get("platform") as string) || "AR-15";
+  const [platform, setPlatform] = useState<string>(initialPlatform);
+
   const category = useMemo(
     () => CATEGORIES.find((c) => c.id === categoryId),
     [categoryId],
@@ -86,10 +100,9 @@ export default function CategoryPage() {
         setError(null);
 
         const search = new URLSearchParams();
-        search.set("platform", "AR-15");
-        search.set("categorySlug", categoryId);
+        search.set("platform", platform);
 
-        const url = `${API_BASE_URL}/api/gunbuilder/products/by-category?${search.toString()}`;
+        const url = `${API_BASE_URL}/api/products?${search.toString()}`;
 
         const res = await fetch(url, { signal: controller.signal });
 
@@ -123,7 +136,7 @@ export default function CategoryPage() {
     fetchCategoryParts();
 
     return () => controller.abort();
-  }, [categoryId]);
+  }, [categoryId, platform]);
 
   //  persist build to localStorage whenever it changes
   useEffect(() => {
@@ -275,10 +288,16 @@ export default function CategoryPage() {
     return filteredParts.slice(startIndex, startIndex + PAGE_SIZE);
   }, [filteredParts, currentPage, PAGE_SIZE]);
 
-    useEffect(() => {
+  useEffect(() => {
     // whenever the category or filters change, jump back to page 1
     setCurrentPage(1);
-  }, [categoryId, brandFilter, sortBy, searchQuery, priceRange, inStockOnly]);
+  }, [categoryId, brandFilter, sortBy, searchQuery, priceRange, inStockOnly, platform]);
+
+  useEffect(() => {
+    const nextPlatform =
+      (searchParams.get("platform") as string) || "AR-15";
+    setPlatform(nextPlatform);
+  }, [searchParams]);
 
   const visibleRange = useMemo(() => {
     if (filteredParts.length === 0) {
@@ -588,6 +607,26 @@ export default function CategoryPage() {
                       )}
                     </div>
                   </div>
+                  <div className="flex items-center gap-2">
+                    <label
+                      htmlFor="platform-select"
+                      className="text-xs text-zinc-500"
+                    >
+                      Platform
+                    </label>
+                    <select
+                      id="platform-select"
+                      value={platform}
+                      onChange={(e) => setPlatform(e.target.value)}
+                      className="rounded-md border border-zinc-700 bg-zinc-900/70 px-2 py-1 text-xs text-zinc-200 focus:outline-none focus:ring-1 focus:ring-amber-400"
+                    >
+                      {PLATFORMS.map((p) => (
+                        <option key={p} value={p}>
+                          {p}
+                        </option>
+                      ))}
+                    </select>
+                  </div>
                   <div className="flex items-center gap-2">
                     <label
                       htmlFor="sort-by"
@@ -660,7 +699,10 @@ export default function CategoryPage() {
                       </div>
                       <div className="mt-2 flex gap-2">
                         <Link
-                          href={`/builder/${categoryId}/${part.id}`}
+                          href={{
+                            pathname: `/builder/${categoryId}/${part.id}-${slugify(part.name)}`,
+                            query: { platform },
+                          }}
                           className="flex-1 rounded-md border border-zinc-700 bg-zinc-800/50 px-3 py-2 text-center text-xs font-medium text-zinc-300 transition-colors hover:border-zinc-600 hover:bg-zinc-700"
                         >
                           View Details
@@ -723,7 +765,10 @@ export default function CategoryPage() {
                           </div>
                           <div className="flex justify-end gap-2">
                             <Link
-                              href={`/builder/${categoryId}/${part.id}`}
+                              href={{
+                                pathname: `/builder/${categoryId}/${part.id}-${slugify(part.name)}`,
+                                query: { platform },
+                              }}
                               className="whitespace-nowrap rounded-md border border-zinc-700 bg-zinc-800/50 px-3 py-1.5 text-xs font-medium text-zinc-300 transition-colors hover:border-zinc-600 hover:bg-zinc-700"
                             >
                               View Details
diff --git a/app/(builder)/builder/layout.tsx b/app/(builder)/builder/layout.tsx
index b04be4c..6280c91 100644
--- a/app/(builder)/builder/layout.tsx
+++ b/app/(builder)/builder/layout.tsx
@@ -24,35 +24,3 @@ export default function BuilderLayout({ children }: { children: ReactNode }) {
   );
 }
 
-
-// 
-// Original homepage. will delete after testing 
-// 
-
-// import "./globals.css";
-// import type { ReactNode } from "react";
-// import { AuthProvider } from "@/context/AuthContext";
-// import { TopNav } from "@/components/TopNav";
-// import { BuilderNav } from "@/components/BuilderNav";
-
-// export const metadata = {
-//   title: {
-//     default: "Battl Builder",
-//     template: "%s | Battl Builder",
-//   },
-//   description: "Battl Builder — the smarter, faster, data‑driven way to build your next firearm.",
-// };
-
-// export default function RootLayout({ children }: { children: ReactNode }) {
-//   return (
-//     <html lang="en">
-//       <body className="bg-black text-zinc-100">
-//         <AuthProvider>
-//           <TopNav />
-//           <BuilderNav />
-//           <main className="min-h-screen">{children}</main>
-//         </AuthProvider>
-//       </body>
-//     </html>
-//   );
-// }
diff --git a/app/(builder)/builder/page.tsx b/app/(builder)/builder/page.tsx
index f5cd4c1..2bde5b7 100644
--- a/app/(builder)/builder/page.tsx
+++ b/app/(builder)/builder/page.tsx
@@ -20,6 +20,8 @@ type GunbuilderProductFromApi = {
   buyUrl: string | null;
 };
 
+const PLATFORMS = ["AR-15", "AR-10", "AR-9"] as const;
+
 const API_BASE_URL =
   process.env.NEXT_PUBLIC_API_BASE_URL ?? "http://localhost:8080";
 
@@ -85,6 +87,7 @@ export default function GunbuilderPage() {
   const [parts, setParts] = useState<Part[]>([]);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
+  const [platform, setPlatform] = useState<(typeof PLATFORMS)[number]>("AR-15");
   const [build, setBuild] = useState<BuildState>(() => {
     if (typeof window !== "undefined") {
       const stored = localStorage.getItem(STORAGE_KEY);
@@ -110,8 +113,10 @@ export default function GunbuilderPage() {
         setError(null);
 
         const res = await fetch(
-          `${API_BASE_URL}/api/products/gunbuilder?platform=AR-15`,
-          { signal: controller.signal },
+          `${API_BASE_URL}/api/products?platform=${encodeURIComponent(
+            platform
+          )}`,
+          { signal: controller.signal }
         );
 
         if (!res.ok) {
@@ -121,29 +126,28 @@ export default function GunbuilderPage() {
         const data: GunbuilderProductFromApi[] = await res.json();
 
         const normalized: Part[] = data
-        .map((p): Part | null => {
-          const categoryId = PART_ROLE_TO_CATEGORY[p.partRole];
-          if (!categoryId) {
-            // Skip any parts we don't know how to map yet
-            return null;
-          }
+          .map((p): Part | null => {
+            const categoryId = PART_ROLE_TO_CATEGORY[p.partRole];
+            if (!categoryId) {
+              // Skip any parts we don't know how to map yet
+              return null;
+            }
 
-          const buyUrl = p.buyUrl ?? undefined;
-
-          return {
-            id: String(p.id), // ALWAYS string
-            categoryId,
-            name: p.name,
-            brand: p.brand,
-            price: p.price ?? 0,
-            imageUrl: p.mainImageUrl ?? undefined,
-            affiliateUrl: buyUrl, // main link
-            url: buyUrl,          // 👈optional alias if you still reference .url. maybe pretty url?
-            notes: undefined,
-          };
-        })
-        .filter((p): p is Part => p !== null);
+            const buyUrl = p.buyUrl ?? undefined;
 
+            return {
+              id: String(p.id), // ALWAYS string
+              categoryId,
+              name: p.name,
+              brand: p.brand,
+              price: p.price ?? 0,
+              imageUrl: p.mainImageUrl ?? undefined,
+              affiliateUrl: buyUrl, // main link
+              url: buyUrl, // 👈optional alias if you still reference .url. maybe pretty url?
+              notes: undefined,
+            };
+          })
+          .filter((p): p is Part => p !== null);
 
         setParts(normalized);
       } catch (err: any) {
@@ -157,7 +161,16 @@ export default function GunbuilderPage() {
     fetchProducts();
 
     return () => controller.abort();
-  }, []);
+  }, [platform]);
+
+  useEffect(() => {
+    // When the platform changes, reset the current build so we don't
+    // show stale part selections from a different platform.
+    setBuild({});
+    if (typeof window !== "undefined") {
+      localStorage.removeItem(STORAGE_KEY);
+    }
+  }, [platform]);
 
   // Handle URL query parameter for part selection (?select=upper:165)
   useEffect(() => {
@@ -191,9 +204,7 @@ export default function GunbuilderPage() {
   const partsByCategory: Record<CategoryId, Part[]> = useMemo(() => {
     const grouped = {} as Record<CategoryId, Part[]>;
     for (const category of CATEGORIES) {
-      grouped[category.id] = parts.filter(
-        (p) => p.categoryId === category.id,
-      );
+      grouped[category.id] = parts.filter((p) => p.categoryId === category.id);
     }
     return grouped;
   }, [parts]);
@@ -201,7 +212,7 @@ export default function GunbuilderPage() {
   const selectedParts: Part[] = useMemo(() => {
     return Object.entries(build)
       .map(([categoryId, partId]) =>
-        parts.find((p) => p.id === partId && p.categoryId === categoryId),
+        parts.find((p) => p.id === partId && p.categoryId === categoryId)
       )
       .filter(Boolean) as Part[];
   }, [build, parts]);
@@ -212,14 +223,14 @@ export default function GunbuilderPage() {
         Object.entries(build).map(([categoryId, partId]) => [
           categoryId as CategoryId,
           partId ? true : false,
-        ]),
+        ])
       ) as Record<CategoryId, unknown>,
-    [build],
+    [build]
   );
 
   const totalPrice = useMemo(
     () => selectedParts.reduce((sum, p) => sum + p.price, 0),
-    [selectedParts],
+    [selectedParts]
   );
 
   useEffect(() => {
@@ -236,7 +247,7 @@ export default function GunbuilderPage() {
       const encoded = window.btoa(payload);
       const origin = window.location?.origin ?? "";
       const url = `${origin}/builder/build?build=${encodeURIComponent(
-        encoded,
+        encoded
       )}`;
       setShareUrl(url);
     } catch {
@@ -254,10 +265,10 @@ export default function GunbuilderPage() {
   // Use group ordering for the summary as well
   const summaryCategoryOrder: CategoryId[] = useMemo(
     () =>
-      CATEGORY_GROUPS.flatMap((group) => group.categoryIds).filter(
-        (id) => CATEGORIES.some((c) => c.id === id),
+      CATEGORY_GROUPS.flatMap((group) => group.categoryIds).filter((id) =>
+        CATEGORIES.some((c) => c.id === id)
       ),
-    [],
+    []
   );
 
   const handleShare = async () => {
@@ -278,14 +289,14 @@ export default function GunbuilderPage() {
 
       const selectedPartId = build[cat.id];
       const part = parts.find(
-        (p) => p.id === selectedPartId && p.categoryId === cat.id,
+        (p) => p.id === selectedPartId && p.categoryId === cat.id
       );
 
       if (part) {
         lines.push(
           `${cat.name}: ${part.brand} — ${part.name} ($${part.price.toFixed(
-            2,
-          )})`,
+            2
+          )})`
         );
       } else {
         lines.push(`${cat.name}: [Not selected]`);
@@ -299,7 +310,7 @@ export default function GunbuilderPage() {
       setShareStatus("Build summary copied to clipboard.");
     } catch {
       setShareStatus(
-        "Could not access clipboard. You can copy from the build summary page.",
+        "Could not access clipboard. You can copy from the build summary page."
       );
     }
   };
@@ -334,7 +345,9 @@ export default function GunbuilderPage() {
         setShareStatus("Share dialog opened.");
       } catch {
         // User canceled or share failed; keep it quiet but let them know
-        setShareStatus("Share canceled or unavailable. You can copy the link instead.");
+        setShareStatus(
+          "Share canceled or unavailable. You can copy the link instead."
+        );
       }
     } else {
       // Fallback to copying the link
@@ -344,7 +357,6 @@ export default function GunbuilderPage() {
 
   return (
     <main className="min-h-screen bg-black text-zinc-50">
-      
       <div className="mx-auto max-w-6xl px-4 py-6 lg:py-10">
         {/* Header */}
         <header className="mb-6">
@@ -361,10 +373,31 @@ export default function GunbuilderPage() {
               update as you go. This early-access builder keeps your setup saved
               locally so you can come back and refine it anytime.
             </p>
+
+            <div className="mt-4 flex flex-wrap items-center gap-3">
+              <label className="text-xs font-medium text-zinc-400 flex items-center gap-2">
+                Platform
+                <select
+                  value={platform}
+                  onChange={(e) =>
+                    setPlatform(e.target.value as (typeof PLATFORMS)[number])
+                  }
+                  className="rounded-md border border-zinc-700 bg-zinc-900 px-2 py-1 text-xs text-zinc-100 focus:outline-none focus:ring-1 focus:ring-amber-400"
+                >
+                  {PLATFORMS.map((p) => (
+                    <option key={p} value={p}>
+                      {p}
+                    </option>
+                  ))}
+                </select>
+              </label>
+              <p className="text-[0.7rem] text-zinc-500">
+                Parts list updates automatically when you change platforms.
+              </p>
+            </div>
           </div>
         </header>
 
-
         {/* Build summary panel */}
         <section className="mb-6 rounded-lg border border-zinc-800 bg-zinc-950/80 p-3 md:p-4 flex flex-col gap-3 md:flex-row md:items-start md:justify-between">
           {/* Left: title + totals + primary actions */}
@@ -416,7 +449,9 @@ export default function GunbuilderPage() {
                 }}
                 disabled={selectedParts.length === 0}
                 className={`w-full sm:w-auto rounded-md border border-zinc-700 bg-zinc-900/50 px-3 py-2 text-sm font-medium text-zinc-300 hover:bg-zinc-800 hover:border-zinc-600 transition-colors ${
-                  selectedParts.length === 0 ? "opacity-40 cursor-not-allowed" : ""
+                  selectedParts.length === 0
+                    ? "opacity-40 cursor-not-allowed"
+                    : ""
                 }`}
               >
                 Clear Build
@@ -432,8 +467,8 @@ export default function GunbuilderPage() {
                   Share Your Build
                 </h3>
                 <p className="mt-1 text-[0.7rem] text-zinc-500">
-                  Share this link to let others view your build or bookmark it to come
-                  back later.
+                  Share this link to let others view your build or bookmark it
+                  to come back later.
                 </p>
                 <div className="mt-2 flex flex-col gap-2 md:flex-row md:items-center">
                   <div className="flex-1">
@@ -468,9 +503,7 @@ export default function GunbuilderPage() {
             )}
 
             {shareStatus && (
-              <p className="mt-1 text-[0.7rem] text-zinc-500">
-                {shareStatus}
-              </p>
+              <p className="mt-1 text-[0.7rem] text-zinc-500">{shareStatus}</p>
             )}
           </div>
         </section>
@@ -511,15 +544,12 @@ export default function GunbuilderPage() {
         <section className="rounded-lg border border-zinc-800 bg-zinc-950/60 p-3 md:p-4">
           <p className="mb-4 text-xs text-zinc-500">
             Work top-down through the major sections. Each row shows your
-            current pick for that part type, with price and a direct buy
-            link—or a quick way to choose a part if you haven&apos;t picked
-            one yet.
+            current pick for that part type, with price and a direct buy link—or
+            a quick way to choose a part if you haven&apos;t picked one yet.
           </p>
 
           {loading && (
-            <p className="text-sm text-zinc-500">
-              Loading parts from backend…
-            </p>
+            <p className="text-sm text-zinc-500">Loading parts from backend…</p>
           )}
           {error && !loading && (
             <p className="text-sm text-red-400">
@@ -532,7 +562,7 @@ export default function GunbuilderPage() {
             <div className="space-y-6">
               {CATEGORY_GROUPS.map((group) => {
                 const groupCategories = CATEGORIES.filter((c) =>
-                  group.categoryIds.includes(c.id as CategoryId),
+                  group.categoryIds.includes(c.id as CategoryId)
                 );
 
                 if (groupCategories.length === 0) {
@@ -584,7 +614,7 @@ export default function GunbuilderPage() {
                               partsByCategory[category.id] ?? [];
                             const selectedPartId = build[category.id];
                             const selectedPart = categoryParts.find(
-                              (p) => p.id === selectedPartId,
+                              (p) => p.id === selectedPartId
                             );
                             const hasParts = categoryParts.length > 0;
 
@@ -663,10 +693,9 @@ export default function GunbuilderPage() {
                                       </>
                                     ) : hasParts ? (
                                       <Link
-                                        href={`/builder/${category.id}`}
-                                        className="inline-flex rounded-md border border-zinc-700 bg-zinc-900/70 px-2.5 py-1 text-[0.7rem] font-medium text-zinc-200 hover:bg-zinc-800 hover:border-zinc-600 transition-colors"
-                                        onClick={() => {
-                                          // If you want to pre-select something later, you can handle here.
+                                        href={{
+                                          pathname: `/builder/${category.id}`,
+                                          query: { platform },
                                         }}
                                       >
                                         Choose a Part
@@ -729,4 +758,4 @@ export default function GunbuilderPage() {
       </div>
     </main>
   );
-}
\ No newline at end of file
+}
diff --git a/app/page.tsx b/app/page.tsx
index d8adb76..4fb3f2d 100644
--- a/app/page.tsx
+++ b/app/page.tsx
@@ -96,7 +96,6 @@ export default function HomePage() {
         {/* Top Bar / Logo */}
         <header className="flex items-center justify-between gap-4">
           <div className="flex items-center gap-3">
-            {/* Logo slot – replace src with your actual logo file */}
             <div className="flex items-center">
               <Image
                 src="/battl/battl-logo-mark-2.svg"
diff --git a/components/TopNav.tsx b/components/TopNav.tsx
index babf251..cd5071e 100644
--- a/components/TopNav.tsx
+++ b/components/TopNav.tsx
@@ -2,6 +2,8 @@
 "use client";
 
 import Link from "next/link";
+import Image from "next/image";
+
 import { useAuth } from "@/context/AuthContext";
 
 export function TopNav() {
@@ -19,7 +21,14 @@ export function TopNav() {
           href="/"
           className="text-xs font-semibold tracking-[0.2em] uppercase text-zinc-400"
         >
-          Battl Builder
+          
+              <Image
+                src="/battl/battl-logo-mark-2.svg"
+                alt="Battl Builders Logo"
+                width={260} // adjust to taste
+                height={48} // adjust to taste
+                className="block"
+              />
         </Link>
 
         {/* Right side actions */}
diff --git a/data/gunbuilderParts.ts b/data/gunbuilderParts.ts
index 90d7ed5..91a0b3e 100644
--- a/data/gunbuilderParts.ts
+++ b/data/gunbuilderParts.ts
@@ -1,163 +1,68 @@
-import type { Category, Part } from "@/types/gunbuilder";
+import type { Category } from "@/types/gunbuilder";
+
+export const CATEGORY_SLUGS = {
+  lower: "lower",
+  "complete-lower": "complete-lower",
+  "lower-parts": "lower-parts",
+  trigger: "trigger",
+  grip: "grip",
+  safety: "safety",
+  buffer: "buffer",
+  stock: "stock",
+
+  upper: "upper",
+  "complete-upper": "complete-upper",
+  barrel: "barrel",
+  handguard: "handguard",
+  "gas-block": "gas-block",
+  "gas-tube": "gas-tube",
+  "muzzle-device": "muzzle-device",
+  bcg: "bcg",
+  sights: "sights",
+  "charging-handle": "charging-handle",
+  suppressor: "suppressor",
+  optic: "optic",
+
+  magazine: "magazine",
+  "weapon-light": "weapon-light",
+  foregrip: "foregrip",
+  bipod: "bipod",
+  sling: "sling",
+  "rail-accessory": "rail-accessory",
+  tools: "tools",
+} as const;
 
 export const CATEGORIES: Category[] = [
-  // LOWER
-  {
-    id: "lower",
-    name: "Stripped Lowers",
-    description: "Serialized lower – the foundation of the build.",
-    group: "lower",
-  },
-  {
-    id: "completeLower",
-    name: "Complete Lowers",
-    description: "Factory-built lower with stock, buffer system, and controls.",
-    group: "lower",
-  },
-  {
-    id: "lowerParts",
-    name: "Lower Parts Kits",
-    description: "Pins, springs, and controls for the lower.",
-    group: "lower",
-  },
-  {
-    id: "trigger",
-    name: "Trigger / Fire Control",
-    description: "Single-stage, two-stage, and match triggers.",
-    group: "lower",
-  },
-  {
-    id: "grip",
-    name: "Pistol Grip",
-    description: "Grips that shape how the rifle handles.",
-    group: "lower",
-  },
-  {
-    id: "safety",
-    name: "Safety / Selector",
-    description: "Ambi selectors and control upgrades.",
-    group: "lower",
-  },
-  {
-    id: "buffer",
-    name: "Buffer System",
-    description: "Buffer tube, buffer, spring, and related parts.",
-    group: "lower",
-  },
-  {
-    id: "stock",
-    name: "Stock / Brace",
-    description: "Adjustable, fixed, and minimalist stocks.",
-    group: "lower",
-  },
+  // Lower group
+  { id: "lower", name: "Stripped Lowers", group: "lower", slug: CATEGORY_SLUGS.lower },
+  { id: "complete-lower", name: "Complete Lower", group: "lower", slug: CATEGORY_SLUGS["complete-lower"] },
+  { id: "lower-parts", name: "Lower Parts Kit", group: "lower", slug: CATEGORY_SLUGS["lower-parts"] },
+  { id: "trigger", name: "Trigger / Fire Control", group: "lower", slug: CATEGORY_SLUGS.trigger },
+  { id: "grip", name: "Pistol Grip", group: "lower", slug: CATEGORY_SLUGS.grip },
+  { id: "safety", name: "Safety / Selector", group: "lower", slug: CATEGORY_SLUGS.safety },
+  { id: "buffer", name: "Buffer System", group: "lower", slug: CATEGORY_SLUGS.buffer },
+  { id: "stock", name: "Stock / Brace", group: "lower", slug: CATEGORY_SLUGS.stock },
 
-  // UPPER
-  {
-    id: "upper",
-    name: "Stripped Uppers",
-    description: "The core of the top half of your build.",
-    group: "upper",
-  },
-  {
-    id: "completeUpper",
-    name: "Complete Uppers",
-    description: "Pre-assembled uppers ready to pin and shoot.",
-    group: "upper",
-  },
-  {
-    id: "bcg",
-    name: "Bolt Carriers",
-    description: "The heartbeat of the rifle’s cycling.",
-    group: "upper",
-  },
-  {
-    id: "barrel",
-    name: "Barrels",
-    description: "Different lengths, profiles, and calibers.",
-    group: "upper",
-  },
-  {
-    id: "gasBlock",
-    name: "Gas Blocks",
-    description: "Standard and adjustable gas blocks.",
-    group: "upper",
-  },
-  {
-    id: "gasTube",
-    name: "Gas Tubes",
-    description: "Carbine, mid, rifle, and more.",
-    group: "upper",
-  },
-  {
-    id: "muzzleDevice",
-    name: "Muzzle Devices",
-    description: "Brakes, comps, and flash hiders.",
-    group: "upper",
-  },
-  {
-    id: "suppressor",
-    name: "Suppressors",
-    description: "Hearing-safe setups and hosts.",
-    group: "upper",
-  },
-  {
-    id: "handguard",
-    name: "Handguards / Rails",
-    description: "M-LOK rails and front-end furniture.",
-    group: "upper",
-  },
-  {
-    id: "chargingHandle",
-    name: "Charging Handles",
-    description: "Standard and ambi charging handles.",
-    group: "upper",
-  },
-  {
-    id: "sights",
-    name: "Iron Sights",
-    description: "Backup and primary irons.",
-    group: "upper",
-  },
-  {
-    id: "optic",
-    name: "Optics",
-    description: "LPVOs, red dots, and magnifiers.",
-    group: "upper",
-  },
-  // ACCESSORIES GROUP
-  {
-    id: "magazine",
-    name: "Magazines",
-    group: "accessories",
-  },
-  {
-    id: "weaponLight",
-    name: "Weapon Lights & Lasers",
-    group: "accessories",
-  },
-  {
-    id: "foregrip",
-    name: "Vertical / Angled Grips",
-    group: "accessories",
-  },
-  {
-    id: "bipod",
-    name: "Bipods",
-    group: "accessories",
-  },
-  {
-    id: "sling",
-    name: "Slings & Mounts",
-    group: "accessories",
-  },
-  {
-    id: "railAccessory",
-    name: "Rail Sections & Covers",
-    group: "accessories",
-  },
-  {
-    id: "tools",
-    name: "Tools & Maintenance",
-    group: "accessories",
-  },
-];
+  // Upper group
+  { id: "upper", name: "Stripped Upper", group: "upper", slug: CATEGORY_SLUGS.upper },
+  { id: "complete-upper", name: "Complete Upper", group: "upper", slug: CATEGORY_SLUGS["complete-upper"] },
+  { id: "barrel", name: "Barrels", group: "upper", slug: CATEGORY_SLUGS.barrel },
+  { id: "handguard", name: "Handguards / Rails", group: "upper", slug: CATEGORY_SLUGS.handguard },
+  { id: "gas-block", name: "Gas Block", group: "upper", slug: CATEGORY_SLUGS["gas-block"] },
+  { id: "gas-tube", name: "Gas Tube", group: "upper", slug: CATEGORY_SLUGS["gas-tube"] },
+  { id: "muzzle-device", name: "Muzzle Device", group: "upper", slug: CATEGORY_SLUGS["muzzle-device"] },
+  { id: "sights", name: "Iron Sights", group: "upper", slug: CATEGORY_SLUGS.sights },
+  { id: "bcg", name: "Bolt Carrier Group", group: "upper", slug: CATEGORY_SLUGS.bcg },
+  { id: "charging-handle", name: "Charging Handle", group: "upper", slug: CATEGORY_SLUGS["charging-handle"] },
+  { id: "suppressor", name: "Suppressors", group: "upper", slug: CATEGORY_SLUGS.suppressor },
+  { id: "optic", name: "Optics", group: "upper", slug: CATEGORY_SLUGS.optic },
+
+  // Accessories
+  { id: "magazine", name: "Magazines", group: "accessories", slug: CATEGORY_SLUGS.magazine },
+  { id: "weapon-light", name: "Weapon Lights & Lasers", group: "accessories", slug: CATEGORY_SLUGS["weapon-light"] },
+  { id: "foregrip", name: "Vertical / Angled Grips", group: "accessories", slug: CATEGORY_SLUGS.foregrip },
+  { id: "bipod", name: "Bipods", group: "accessories", slug: CATEGORY_SLUGS.bipod },
+  { id: "sling", name: "Slings & Mounts", group: "accessories", slug: CATEGORY_SLUGS.sling },
+  { id: "rail-accessory", name: "Rail Accessories", group: "accessories", slug: CATEGORY_SLUGS["rail-accessory"] },
+  { id: "tools", name: "Tools & Maintenance", group: "accessories", slug: CATEGORY_SLUGS.tools },
+];
\ No newline at end of file
diff --git a/types/gunbuilder.ts b/types/gunbuilder.ts
index 33d84f5..740a18e 100644
--- a/types/gunbuilder.ts
+++ b/types/gunbuilder.ts
@@ -50,3 +50,35 @@ export interface Part {
   imageUrl?: string;
   notes?: string;
 }
+
+export const CATEGORY_SLUGS: Record<CategoryId, string> = {
+  lower: "lower",
+  completeLower: "complete-lower",
+  lowerParts: "lower-parts",
+  trigger: "trigger",
+  grip: "grip",
+  safety: "safety",
+  buffer: "buffer",
+  stock: "stock",
+
+  upper: "upper",
+  completeUpper: "complete-upper",
+  barrel: "barrel",
+  handguard: "handguard",
+  gasBlock: "gas-block",
+  gasTube: "gas-tube",
+  muzzleDevice: "muzzle-device",
+  sights: "sights",
+  bcg: "bcg",
+  chargingHandle: "charging-handle",
+  suppressor: "suppressor",
+  optic: "optic",
+
+  magazine: "magazine",
+  weaponLight: "weapon-light",
+  foregrip: "foregrip",
+  bipod: "bipod",
+  sling: "sling",
+  railAccessory: "rail-accessory",
+  tools: "tools",
+};
\ No newline at end of file