diff --git a/.node-version b/.node-version
new file mode 100644
index 0000000..ccc4c6c
--- /dev/null
+++ b/.node-version
@@ -0,0 +1 @@
+20.20.2
diff --git a/README.md b/README.md
index 7257982..2818ffb 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,8 @@ The source code is available at [github.com/ChrisAdamsdevelopment/SpectraCleanse
 For a step-by-step manual validation flow (local, API smoke, auth, billing, upload, cleanse, Docker, and production readiness), see [`docs/manual-qa-checklist.md`](docs/manual-qa-checklist.md).
 
 - Browser metadata analysis uses maintained `music-metadata` with graceful fallback (`parseError`) when parsing fails, times out, or is skipped for very large files.
-- Quick Cleanse metadata writing remains local/browser-side (MP3 via `browser-id3-writer`), while Full Server Cleanse still runs through `/api/process`.
+- Quick Cleanse metadata writing remains local/browser-side (MP3 via `browser-id3-writer`).
+- Full Server Cleanse runs through `/api/process` for supported non-MP3 formats; MP3 requests are rejected with HTTP `422` and guidance to use Quick Cleanse Browser.
 
 ---
 
@@ -57,6 +58,16 @@ Questions, partnerships, or enterprise enquiries: [hello@spectracleanse.com](mai
 
 ---
 
+
+## Native Node deployment runtime
+
+- Native Render/Node deployments should use **Node 20.20.2** (recommended) or a Node version within the supported engines range: `>=18 <23`.
+- If Render defaults your service to a newer Node release, set `NODE_VERSION=20.20.2` in the service environment.
+- Node 24 is currently not supported for native installs in validation because `better-sqlite3` native compilation failed under Node 24.
+- Docker deployments already pin Node 18 via the repo Dockerfile.
+
+---
+
 ## Docker production deployment
 
 This repository includes a multi-stage `Dockerfile` that builds the frontend and packages `dist/` into the final runtime image so `server.js` can serve the SPA in production.
diff --git a/app.tsx b/app.tsx
index f1ebca7..54dbcba 100644
--- a/app.tsx
+++ b/app.tsx
@@ -654,7 +654,7 @@ export default function App() {
 
         if (!res.ok) {
           const errBody = await res.json().catch(() => ({ error: `HTTP ${res.status}` }));
-          throw new Error(errBody.error || `Server error ${res.status}`);
+          throw new Error(errBody.detail || errBody.error || `Server error ${res.status}`);
         }
 
         const blob         = await res.blob();
diff --git a/docs/manual-qa-checklist.md b/docs/manual-qa-checklist.md
index a73d6e6..83381cf 100644
--- a/docs/manual-qa-checklist.md
+++ b/docs/manual-qa-checklist.md
@@ -98,13 +98,17 @@ Run these checks against your local server:
 
 ## 9) Full Server Cleanse QA
 
-1. Run server cleanse on a supported file.
+1. Run server cleanse on a supported non-MP3 file.
 2. Verify `/api/process` returns downloadable file response.
-3. Verify usage meter/counter updates.
+3. Verify usage meter/counter updates only after successful delivered files.
 4. Verify forensic/report information appears when present.
-5. Force or simulate `401` from protected endpoint.
+5. Upload MP3 to Full Server Cleanse and verify HTTP `422` JSON:
+   - Expected error: `MP3 server cleanse is not supported`.
+   - Expected detail tells user to use Quick Cleanse (Browser) for MP3.
+   - Expected usage counter does **not** increment on this rejection.
+6. Force or simulate `401` from protected endpoint.
    - Expected: user is logged out/reauth requested.
-6. Force or simulate `402`.
+7. Force or simulate `402`.
    - Expected: upgrade modal opens.
 
 ## 10) Object URL / download safety QA
diff --git a/package-lock.json b/package-lock.json
index 74d1257..bb6d6e5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -36,7 +36,7 @@
         "vite": "^4.5.14"
       },
       "engines": {
-        "node": ">=18"
+        "node": ">=18 <23"
       }
     },
     "node_modules/@alloc/quick-lru": {
diff --git a/package.json b/package.json
index 50cd751..74ee96f 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "SpectraCleanse AI",
   "main": "server.js",
   "engines": {
-    "node": ">=18"
+    "node": ">=18 <23"
   },
   "scripts": {
     "start": "node server.js",
diff --git a/server.js b/server.js
index 9fda7da..f28fcbb 100644
--- a/server.js
+++ b/server.js
@@ -451,6 +451,19 @@ app.post('/api/process', requireAuth, upload.single('file'), async (req, res) =>
   if (!req.file) return res.status(400).json({ error: 'No file uploaded' });
 
   const userId = req.user.sub;
+  const inputPath = req.file.path;
+  const originalName = req.file.originalname || '';
+  const ext = path.extname(originalName).toLowerCase() || '.mp3';
+  const mime = (req.file.mimetype || '').toLowerCase();
+  const isMp3 = ext === '.mp3' || mime === 'audio/mpeg';
+
+  if (isMp3) {
+    await fs.remove(inputPath).catch(() => {});
+    return res.status(422).json({
+      error: 'MP3 server cleanse is not supported',
+      detail: 'Use Quick Cleanse (Browser) for MP3 metadata rewriting, or upload MP4/M4A/WAV/FLAC for Full Server Cleanse.',
+    });
+  }
 
   // ── Tier-based usage enforcement ─────────────────────────────────────────
   // Always re-read plan from DB so upgrades (via webhook) take effect
@@ -474,8 +487,6 @@ app.post('/api/process', requireAuth, upload.single('file'), async (req, res) =>
   // ── End enforcement ───────────────────────────────────────────────────────
 
   const { title, description, tags, artist, genre, lyrics, platform = 'General' } = req.body;
-  const inputPath  = req.file.path;
-  const ext        = path.extname(req.file.originalname).toLowerCase() || '.mp3';
   const outputPath = path.join('uploads', `out_${Date.now()}${ext}`);
 
   try {
@@ -490,16 +501,21 @@ app.post('/api/process', requireAuth, upload.single('file'), async (req, res) =>
     const beforeTags = await exiftool.read(outputPath);
     const beforeKeys = new Set(Object.keys(beforeTags));
 
-    // Phase 2: Nuclear wipe
+    // Phase 2: Nuclear wipe (supported exiftool-vendored path only)
     try {
-      await exiftool.execute('-all=', '-XMP:all=', '-IPTC:all=', '-overwrite_original', outputPath);
-    } catch (wipeErr) {
-      console.warn('Primary metadata wipe failed, retrying with exiftool.write fallback:', wipeErr.message);
       await exiftool.write(
         outputPath,
         {},
         ['-all=', '-XMP:all=', '-IPTC:all=', '-overwrite_original']
       );
+    } catch (wipeErr) {
+      console.warn('Primary metadata wipe failed:', wipeErr.message);
+      await fs.remove(inputPath).catch(() => {});
+      await fs.remove(outputPath).catch(() => {});
+      return res.status(422).json({
+        error: 'Server cleanse unsupported for this format',
+        detail: 'This file format cannot be safely metadata-wiped on the server. Use Quick Cleanse (Browser) for MP3 or try MP4/M4A/WAV/FLAC for Full Server Cleanse.',
+      });
     }
 
     // Phase 3: Platform-aware SEO injection