diff --git a/netlify.toml b/netlify.toml
index 6c4fca7..828ab2d 100644
--- a/netlify.toml
+++ b/netlify.toml
@@ -3,6 +3,9 @@
   command = "corepack prepare npm@10.9.2 --activate && npm install --prefix . && npm run build --prefix ."
   publish = "out"
 
+[functions]
+  directory = "netlify/functions"
+
 [build.environment]
   NODE_VERSION = "20"
   NODE_OPTIONS = "--max-old-space-size=4096"
diff --git a/netlify/functions/analyze.js b/netlify/functions/analyze.js
new file mode 100644
index 0000000..eb72cfc
--- /dev/null
+++ b/netlify/functions/analyze.js
@@ -0,0 +1,49 @@
+// Unified analysis gateway (mock/preview). Real integrations (yt-dlp/model) should be wired to the providers.
+const { promises: fs } = require('fs')
+
+exports.handler = async (event) => {
+  if (event.httpMethod !== 'POST') {
+    return { statusCode: 405, body: 'Method Not Allowed' }
+  }
+
+  // NOTE: Netlify Functions cannot parse multipart by default; here we return a fixed preview response.
+  // In real usage, move this to a full server or add multipart parsing + external service calls.
+  const now = Date.now()
+  const seed = (now % 1000) / 1000
+  const isAIGenerated = seed > 0.5
+  const confidence = Number((0.55 + seed * 0.35).toFixed(3))
+
+  const result = {
+    isAIGenerated,
+    confidence,
+    processingTime: 0.4,
+    modelVersion: 'gateway-preview-v1',
+    decisionSource: 'preview',
+    source: {
+      kind: 'file',
+      fileName: 'preview',
+      fileSizeBytes: 0,
+      mimeType: 'application/octet-stream'
+    },
+    features: {
+      spectralRegularity: Number(((seed + 0.17) % 1).toFixed(3)),
+      temporalPatterns: Number(((seed + 0.43) % 1).toFixed(3)),
+      harmonicStructure: Number(((seed + 0.71) % 1).toFixed(3)),
+      artificialIndicators: [
+        'Preview-only decision based on fingerprint.',
+        'No model inference was available at request time.'
+      ]
+    },
+    audioInfo: {
+      duration: 0,
+      sampleRate: 44100,
+      bitrate: 192,
+      format: 'PREVIEW'
+    }
+  }
+
+  return {
+    statusCode: 200,
+    body: JSON.stringify({ result, warnings: ['gateway_mock_preview'] })
+  }
+}
diff --git a/platform/hooks/analysisGateway.ts b/platform/hooks/analysisGateway.ts
new file mode 100644
index 0000000..2a6fe5e
--- /dev/null
+++ b/platform/hooks/analysisGateway.ts
@@ -0,0 +1,59 @@
+import type { AnalysisResult, AnalysisErrorCode } from '@/hooks/analysisTypes'
+
+export type SourceType = 'youtube' | 'file' | 'spotify' | 'apple'
+
+export interface AnalyzePayload {
+  sourceType: SourceType
+  url?: string
+  file?: File
+}
+
+export interface AnalyzeResponse {
+  result?: AnalysisResult
+  warnings?: string[]
+  errors?: string[]
+}
+
+const MAX_BYTES = 30 * 1024 * 1024 // 30MB
+
+export const analyzeSource = async (
+  apiBaseUrl: string | undefined,
+  payload: AnalyzePayload
+): Promise<{ result: AnalysisResult | null; error: AnalysisErrorCode | null }> => {
+  if (!apiBaseUrl) {
+    return { result: null, error: 'backend_not_configured' as AnalysisErrorCode }
+  }
+
+  const formData = new FormData()
+  formData.append('sourceType', payload.sourceType)
+
+  if (payload.url) {
+    formData.append('url', payload.url)
+  }
+
+  if (payload.file) {
+    if (payload.file.size > MAX_BYTES) {
+      return { result: null, error: 'fileTooLarge' }
+    }
+    formData.append('file', payload.file)
+  }
+
+  const response = await fetch(`${apiBaseUrl}/api/analyze`, {
+    method: 'POST',
+    body: formData
+  })
+
+  if (!response.ok) {
+    return { result: null, error: 'backend_unreachable' as AnalysisErrorCode }
+  }
+
+  const data = await response.json() as AnalyzeResponse
+  if (data.errors && data.errors.length) {
+    // Map a few known errors to the existing codes
+    if (data.errors.includes('missing_file')) return { result: null, error: 'missingFile' }
+    if (data.errors.includes('unsupported_source')) return { result: null, error: 'invalidYouTubeUrl' }
+    return { result: null, error: 'backend_unexpected_response' as AnalysisErrorCode }
+  }
+
+  return { result: data.result ?? null, error: null }
+}
diff --git a/platform/hooks/analysisTypes.ts b/platform/hooks/analysisTypes.ts
index 18e5cfc..d986285 100644
--- a/platform/hooks/analysisTypes.ts
+++ b/platform/hooks/analysisTypes.ts
@@ -52,3 +52,6 @@ export type AnalysisErrorCode =
   | 'fileTooLarge'
   | 'fileTooSmall'
   | 'invalidFileName'
+  | 'backend_not_configured'
+  | 'backend_unreachable'
+  | 'backend_unexpected_response'
diff --git a/platform/hooks/analysisUtils.ts b/platform/hooks/analysisUtils.ts
index 5e1b470..d69f4c5 100644
--- a/platform/hooks/analysisUtils.ts
+++ b/platform/hooks/analysisUtils.ts
@@ -17,3 +17,11 @@ export const buildFeatureScores = (seed: number) => {
     harmonicStructure: normalized(0.71)
   }
 }
+
+export const previewIndicators = (extra?: string[]) => {
+  const base = [
+    'Preview-only decision based on fingerprint.',
+    'No model inference was available at request time.'
+  ]
+  return extra && extra.length ? [...base, ...extra] : base
+}
diff --git a/platform/hooks/useFileAnalysis.ts b/platform/hooks/useFileAnalysis.ts
index 1b705cf..401c7b8 100644
--- a/platform/hooks/useFileAnalysis.ts
+++ b/platform/hooks/useFileAnalysis.ts
@@ -6,7 +6,7 @@
 
 import { useCallback, useRef, useState } from 'react'
 import type { AnalysisErrorCode, AnalysisResult, ProcessingState } from '@/hooks/analysisTypes'
-import { buildFeatureScores, buildSeed } from '@/hooks/analysisUtils'
+import { buildFeatureScores, buildSeed, previewIndicators } from '@/hooks/analysisUtils'
 
 const MAX_FILE_SIZE_BYTES = 100 * 1024 * 1024
 const MIN_FILE_SIZE_BYTES = 1024
@@ -79,10 +79,7 @@ const buildPreviewResult = (file: File, elapsedSec: number): AnalysisResult => {
     },
     features: {
       ...featureScores,
-      artificialIndicators: [
-        'Preview-only decision based on file fingerprint.',
-        'No model inference was available at request time.'
-      ]
+      artificialIndicators: previewIndicators()
     },
     audioInfo: {
       duration: 0,
diff --git a/platform/hooks/useYouTubeAnalysis.ts b/platform/hooks/useYouTubeAnalysis.ts
index 9bde39b..c171f72 100644
--- a/platform/hooks/useYouTubeAnalysis.ts
+++ b/platform/hooks/useYouTubeAnalysis.ts
@@ -6,7 +6,7 @@
 
 import { useCallback, useMemo, useRef, useState } from 'react'
 import type { AnalysisErrorCode, AnalysisResult, DecisionSource, ProcessingState } from '@/hooks/analysisTypes'
-import { buildFeatureScores, buildSeed } from '@/hooks/analysisUtils'
+import { buildFeatureScores, buildSeed, previewIndicators } from '@/hooks/analysisUtils'
 
 interface ParsedYouTubeUrl {
   videoId: string
@@ -111,10 +111,7 @@ const buildPreviewResult = (
   const confidence = Number((0.55 + seed * 0.35).toFixed(3))
   const featureScores = buildFeatureScores(seed)
 
-  const indicators = [
-    'Preview-only decision based on URL fingerprint.',
-    'No model inference was available at request time.'
-  ]
+  const indicators = previewIndicators()
   if (warnings.length) {
     indicators.push('Warnings reported by the backend pipeline.')
   }