Add public shareable taste profiles

Users can generate a share link for their taste profile via the
"Share My Taste" button. The link opens a public page showing
listening personality, genre breakdown, audio features, and top
artists with a CTA to register. Token-based URL prevents enumeration.

backend/app/api/endpoints/profile.py

@@ -1,7 +1,10 @@
-from fastapi import APIRouter, Depends
+import hashlib
+
+from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from app.core.config import settings
 from app.core.database import get_db
 from app.core.security import get_current_user
 from app.models.user import User
@@ -198,3 +201,164 @@ async def get_taste_profile(
         "track_count": len(all_tracks),
         "playlist_count": len(playlists),
     }
+
+
+async def _build_taste_profile(user_id: int, db: AsyncSession) -> dict:
+    """Build a taste profile dict for the given user_id (shared logic)."""
+    result = await db.execute(
+        select(Playlist).where(Playlist.user_id == user_id)
+    )
+    playlists = list(result.scalars().all())
+
+    all_tracks = []
+    for p in playlists:
+        result = await db.execute(select(Track).where(Track.playlist_id == p.id))
+        all_tracks.extend(result.scalars().all())
+
+    if not all_tracks:
+        return {
+            "genre_breakdown": [],
+            "audio_features": {
+                "energy": 0,
+                "danceability": 0,
+                "valence": 0,
+                "acousticness": 0,
+                "avg_tempo": 0,
+            },
+            "personality": {
+                "label": "New Listener",
+                "description": "Import some playlists to discover your listening personality!",
+                "icon": "music",
+            },
+            "top_artists": [],
+            "track_count": 0,
+            "playlist_count": len(playlists),
+        }
+
+    # Genre breakdown
+    genres_count: dict[str, int] = {}
+    for t in all_tracks:
+        if t.genres:
+            for g in t.genres:
+                genres_count[g] = genres_count.get(g, 0) + 1
+
+    total_genre_mentions = sum(genres_count.values()) or 1
+    top_genres = sorted(genres_count.items(), key=lambda x: x[1], reverse=True)[:10]
+    genre_breakdown = [
+        {"name": g, "percentage": round((c / total_genre_mentions) * 100, 1)}
+        for g, c in top_genres
+    ]
+
+    # Audio features averages + variance
+    energies = []
+    danceabilities = []
+    valences = []
+    acousticnesses = []
+    tempos = []
+
+    for t in all_tracks:
+        if t.energy is not None:
+            energies.append(t.energy)
+        if t.danceability is not None:
+            danceabilities.append(t.danceability)
+        if t.valence is not None:
+            valences.append(t.valence)
+        if t.acousticness is not None:
+            acousticnesses.append(t.acousticness)
+        if t.tempo is not None:
+            tempos.append(t.tempo)
+
+    def avg(lst: list[float]) -> float:
+        return round(sum(lst) / len(lst), 3) if lst else 0
+
+    def variance(lst: list[float]) -> float:
+        if len(lst) < 2:
+            return 0
+        m = sum(lst) / len(lst)
+        return sum((x - m) ** 2 for x in lst) / len(lst)
+
+    avg_energy = avg(energies)
+    avg_danceability = avg(danceabilities)
+    avg_valence = avg(valences)
+    avg_acousticness = avg(acousticnesses)
+    avg_tempo = round(avg(tempos), 0)
+
+    # Personality
+    personality = _determine_personality(
+        genre_count=len(genres_count),
+        avg_energy=avg_energy,
+        avg_valence=avg_valence,
+        avg_acousticness=avg_acousticness,
+        energy_variance=variance(energies),
+        valence_variance=variance(valences),
+    )
+
+    # Top artists
+    artist_count: dict[str, int] = {}
+    for t in all_tracks:
+        artist_count[t.artist] = artist_count.get(t.artist, 0) + 1
+    top_artists_sorted = sorted(artist_count.items(), key=lambda x: x[1], reverse=True)[:8]
+
+    artist_genres: dict[str, str] = {}
+    for t in all_tracks:
+        if t.artist in dict(top_artists_sorted) and t.genres and t.artist not in artist_genres:
+            artist_genres[t.artist] = t.genres[0]
+
+    top_artists = [
+        {
+            "name": name,
+            "track_count": count,
+            "genre": artist_genres.get(name, ""),
+        }
+        for name, count in top_artists_sorted
+    ]
+
+    return {
+        "genre_breakdown": genre_breakdown,
+        "audio_features": {
+            "energy": round(avg_energy * 100),
+            "danceability": round(avg_danceability * 100),
+            "valence": round(avg_valence * 100),
+            "acousticness": round(avg_acousticness * 100),
+            "avg_tempo": avg_tempo,
+        },
+        "personality": personality,
+        "top_artists": top_artists,
+        "track_count": len(all_tracks),
+        "playlist_count": len(playlists),
+    }
+
+
+def _generate_profile_token(user_id: int) -> str:
+    """Generate a deterministic share token for a user's profile."""
+    return hashlib.sha256(
+        f"profile:{user_id}:{settings.SECRET_KEY}".encode()
+    ).hexdigest()[:16]
+
+
+@router.get("/share-link")
+async def get_profile_share_link(user: User = Depends(get_current_user)):
+    """Generate a share link for the user's taste profile."""
+    token = _generate_profile_token(user.id)
+    return {"share_url": f"{settings.FRONTEND_URL}/taste/{user.id}/{token}"}
+
+
+@router.get("/public/{user_id}/{token}")
+async def get_public_profile(
+    user_id: int,
+    token: str,
+    db: AsyncSession = Depends(get_db),
+):
+    """Public taste profile — no auth required."""
+    expected = _generate_profile_token(user_id)
+    if token != expected:
+        raise HTTPException(status_code=404, detail="Invalid profile link")
+
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    if not user:
+        raise HTTPException(status_code=404, detail="Profile not found")
+
+    profile = await _build_taste_profile(user_id, db)
+    profile["name"] = user.name.split()[0]  # First name only for privacy
+    return profile

frontend/src/App.tsx

@@ -22,6 +22,7 @@ import Compatibility from './pages/Compatibility'
 import CrateDigger from './pages/CrateDigger'
 import RabbitHole from './pages/RabbitHole'
 import Settings from './pages/Settings'
+import PublicProfile from './pages/PublicProfile'
 
 function RootRedirect() {
   const { user, loading } = useAuth()
@@ -214,6 +215,7 @@ function AppRoutes() {
         }
       />
       <Route path="/shared/:recId/:token" element={<SharedView />} />
+      <Route path="/taste/:userId/:token" element={<PublicProfile />} />
       <Route path="*" element={<Navigate to="/" replace />} />
     </Routes>
   )

frontend/src/lib/api.ts

@@ -448,6 +448,7 @@ export interface AdminStats {
   users: { total: number; pro: number; free: number }
   playlists: { total: number; total_tracks: number }
   recommendations: { total: number; today: number; this_week: number; this_month: number; saved: number; disliked: number }
+  api_costs: { total_estimated: number; today_estimated: number; total_input_tokens: number; total_output_tokens: number }
   user_breakdown: { id: number; name: string; email: string; is_pro: boolean; created_at: string; recommendation_count: number }[]
 }
 

frontend/src/pages/PublicProfile.tsx

@@ -0,0 +1,232 @@
+import { useState, useEffect } from 'react'
+import { useParams, Link } from 'react-router-dom'
+import { Loader2, Fingerprint, Zap, Music2, CloudSun, Heart, Layers, Globe, Drama, User } from 'lucide-react'
+import { getPublicProfile, type TasteProfileResponse } from '../lib/api'
+
+const personalityIcons: Record<string, typeof Zap> = {
+  zap: Zap,
+  cloud: CloudSun,
+  heart: Heart,
+  layers: Layers,
+  globe: Globe,
+  drama: Drama,
+  music: Music2,
+}
+
+const genreBarColors = [
+  'bg-[#7C3AED]',
+  'bg-[#8B5CF6]',
+  'bg-[#9F6FFB]',
+  'bg-[#A78BFA]',
+  'bg-[#B49BFC]',
+  'bg-[#C4ABFD]',
+  'bg-[#D3BCFE]',
+  'bg-[#DDD6FE]',
+  'bg-[#E8DFFE]',
+  'bg-[#F0EAFF]',
+]
+
+type PublicProfileData = TasteProfileResponse & { name: string }
+
+function possessive(name: string): string {
+  return name.endsWith('s') ? `${name}'` : `${name}'s`
+}
+
+export default function PublicProfile() {
+  const { userId, token } = useParams<{ userId: string; token: string }>()
+  const [profile, setProfile] = useState<PublicProfileData | null>(null)
+  const [loading, setLoading] = useState(true)
+  const [error, setError] = useState<string | null>(null)
+
+  useEffect(() => {
+    if (!userId || !token) return
+    setLoading(true)
+    getPublicProfile(userId, token)
+      .then(setProfile)
+      .catch(() => setError('This profile link is invalid or has expired.'))
+      .finally(() => setLoading(false))
+  }, [userId, token])
+
+  if (loading) {
+    return (
+      <div className="min-h-screen bg-[#FFF7ED] flex items-center justify-center">
+        <div className="w-12 h-12 border-4 border-[#7C3AED] border-t-transparent rounded-full animate-spin" />
+      </div>
+    )
+  }
+
+  if (error || !profile) {
+    return (
+      <div className="min-h-screen bg-[#FFF7ED] flex items-center justify-center p-6">
+        <div className="text-center max-w-md">
+          <h1 className="text-2xl font-bold text-[#1C1917] mb-2">Profile Not Found</h1>
+          <p className="text-[#1C1917]/60 mb-6">{error || 'This taste profile could not be found.'}</p>
+          <Link
+            to="/register"
+            className="inline-block px-6 py-3 bg-[#7C3AED] text-white rounded-xl font-semibold hover:bg-[#6D28D9] transition-colors no-underline"
+          >
+            Discover Your Taste on Vynl
+          </Link>
+        </div>
+      </div>
+    )
+  }
+
+  const PersonalityIcon = personalityIcons[profile.personality.icon] || Music2
+  const maxGenrePercent = profile.genre_breakdown.length > 0
+    ? Math.max(...profile.genre_breakdown.map((g) => g.percentage))
+    : 100
+
+  return (
+    <div className="min-h-screen bg-[#FFF7ED] flex flex-col">
+      {/* Header */}
+      <header className="py-6 px-6 text-center">
+        <Link to="/" className="inline-block no-underline">
+          <h1 className="text-2xl font-bold text-[#7C3AED] tracking-tight">vynl</h1>
+        </Link>
+      </header>
+
+      {/* Content */}
+      <main className="flex-1 px-4 pb-12 max-w-3xl mx-auto w-full space-y-6">
+        {/* Title */}
+        <div className="text-center">
+          <h2 className="text-3xl font-bold text-[#1C1917] flex items-center justify-center gap-3">
+            <Fingerprint className="w-8 h-8 text-[#7C3AED]" />
+            {possessive(profile.name)} Music DNA
+          </h2>
+          <p className="text-[#1C1917]/50 mt-1 text-sm">
+            Built from {profile.track_count} tracks across {profile.playlist_count} playlists
+          </p>
+        </div>
+
+        {/* Listening Personality */}
+        <div className="bg-gradient-to-br from-[#7C3AED] to-[#5B21B6] rounded-2xl p-8 text-white">
+          <div className="flex items-start gap-4">
+            <div className="w-14 h-14 rounded-2xl bg-white/15 flex items-center justify-center flex-shrink-0">
+              <PersonalityIcon className="w-7 h-7 text-white" />
+            </div>
+            <div>
+              <p className="text-purple-200 text-xs font-semibold uppercase tracking-wider mb-1">
+                Listening Personality
+              </p>
+              <h3 className="text-2xl font-bold mb-2">{profile.personality.label}</h3>
+              <p className="text-purple-100 text-sm leading-relaxed">
+                {profile.personality.description}
+              </p>
+            </div>
+          </div>
+        </div>
+
+        {/* Genre DNA */}
+        {profile.genre_breakdown.length > 0 && (
+          <div className="bg-white rounded-2xl border border-[#7C3AED]/10 p-6">
+            <h3 className="text-lg font-semibold text-[#1C1917] mb-5">Genre DNA</h3>
+            <div className="space-y-3">
+              {profile.genre_breakdown.map((genre, i) => (
+                <div key={genre.name} className="flex items-center gap-3">
+                  <span className="text-sm text-[#1C1917] w-28 truncate text-right flex-shrink-0 font-medium">
+                    {genre.name}
+                  </span>
+                  <div className="flex-1 bg-[#F5F3FF] rounded-full h-6 overflow-hidden">
+                    <div
+                      className={`h-full rounded-full ${genreBarColors[i] || genreBarColors[genreBarColors.length - 1]} transition-all duration-700 ease-out flex items-center justify-end pr-2`}
+                      style={{ width: `${(genre.percentage / maxGenrePercent) * 100}%`, minWidth: '2rem' }}
+                    >
+                      <span className="text-xs font-semibold text-white drop-shadow-sm">
+                        {genre.percentage}%
+                      </span>
+                    </div>
+                  </div>
+                </div>
+              ))}
+            </div>
+          </div>
+        )}
+
+        {/* Audio Features */}
+        <div className="bg-white rounded-2xl border border-[#7C3AED]/10 p-6">
+          <h3 className="text-lg font-semibold text-[#1C1917] mb-5">Audio Features</h3>
+          <div className="space-y-4">
+            <PublicAudioMeter label="Energy" value={profile.audio_features.energy} />
+            <PublicAudioMeter label="Danceability" value={profile.audio_features.danceability} />
+            <PublicAudioMeter label="Mood / Valence" value={profile.audio_features.valence} />
+            <PublicAudioMeter label="Acousticness" value={profile.audio_features.acousticness} />
+            <div className="flex items-center gap-3 pt-2 border-t border-[#7C3AED]/10">
+              <span className="text-sm text-[#1C1917] w-28 text-right flex-shrink-0 font-medium">
+                Avg Tempo
+              </span>
+              <div className="flex-1 flex items-center gap-2">
+                <span className="text-2xl font-bold text-[#7C3AED]">{profile.audio_features.avg_tempo}</span>
+                <span className="text-sm text-[#1C1917]/50">BPM</span>
+              </div>
+            </div>
+          </div>
+        </div>
+
+        {/* Top Artists */}
+        {profile.top_artists.length > 0 && (
+          <div className="bg-white rounded-2xl border border-[#7C3AED]/10 p-6">
+            <h3 className="text-lg font-semibold text-[#1C1917] mb-5">Artists That Define Them</h3>
+            <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
+              {profile.top_artists.map((artist) => (
+                <div
+                  key={artist.name}
+                  className="flex items-center gap-3 p-3 rounded-xl bg-[#FFF7ED]/60 border border-[#7C3AED]/5"
+                >
+                  <div className="w-10 h-10 rounded-full bg-[#F5F3FF] flex items-center justify-center flex-shrink-0">
+                    <User className="w-5 h-5 text-[#7C3AED]" />
+                  </div>
+                  <div className="min-w-0">
+                    <p className="text-sm font-semibold text-[#1C1917] truncate">{artist.name}</p>
+                    <p className="text-xs text-[#1C1917]/50">
+                      {artist.track_count} track{artist.track_count !== 1 ? 's' : ''}
+                      {artist.genre ? ` · ${artist.genre}` : ''}
+                    </p>
+                  </div>
+                </div>
+              ))}
+            </div>
+          </div>
+        )}
+
+        {/* CTA */}
+        <div className="bg-white rounded-2xl border border-[#7C3AED]/10 p-8 text-center">
+          <p className="text-[#1C1917]/60 text-sm mb-4">
+            Want to discover your own music DNA?
+          </p>
+          <Link
+            to="/register"
+            className="inline-block px-8 py-3.5 bg-[#7C3AED] text-white rounded-xl font-semibold hover:bg-[#6D28D9] transition-colors no-underline text-base"
+          >
+            Discover Your Taste on Vynl
+          </Link>
+        </div>
+      </main>
+    </div>
+  )
+}
+
+function PublicAudioMeter({ label, value }: { label: string; value: number }) {
+  return (
+    <div className="flex items-center gap-3">
+      <span className="text-sm text-[#1C1917] w-28 text-right flex-shrink-0 font-medium">
+        {label}
+      </span>
+      <div className="flex-1 bg-[#F5F3FF] rounded-full h-5 overflow-hidden">
+        <div
+          className="h-full rounded-full bg-gradient-to-r from-[#7C3AED] to-[#A78BFA] transition-all duration-700 ease-out flex items-center justify-end pr-2"
+          style={{ width: `${value}%`, minWidth: value > 0 ? '1.5rem' : '0' }}
+        >
+          {value > 10 && (
+            <span className="text-xs font-semibold text-white drop-shadow-sm">
+              {value}%
+            </span>
+          )}
+        </div>
+      </div>
+      {value <= 10 && (
+        <span className="text-xs font-medium text-[#1C1917]/50 w-10">{value}%</span>
+      )}
+    </div>
+  )
+}

frontend/src/pages/TasteProfilePage.tsx

@@ -1,6 +1,6 @@
 import { useState, useEffect } from 'react'
-import { Loader2, Fingerprint, Zap, Music2, CloudSun, Heart, Layers, Globe, Drama, User } from 'lucide-react'
-import { getTasteProfile, type TasteProfileResponse } from '../lib/api'
+import { Loader2, Fingerprint, Zap, Music2, CloudSun, Heart, Layers, Globe, Drama, User, Share2, Check, Copy } from 'lucide-react'
+import { getTasteProfile, getProfileShareLink, type TasteProfileResponse } from '../lib/api'
 
 const personalityIcons: Record<string, typeof Zap> = {
   zap: Zap,
@@ -28,6 +28,8 @@ const genreBarColors = [
 export default function TasteProfilePage() {
   const [profile, setProfile] = useState<TasteProfileResponse | null>(null)
   const [loading, setLoading] = useState(true)
+  const [copied, setCopied] = useState(false)
+  const [sharing, setSharing] = useState(false)
 
   useEffect(() => {
     getTasteProfile()
@@ -60,6 +62,7 @@ export default function TasteProfilePage() {
   return (
     <div className="space-y-8 max-w-3xl mx-auto">
       {/* Header */}
+      <div className="flex items-start justify-between gap-4">
         <div>
           <h1 className="text-3xl font-bold text-charcoal flex items-center gap-3">
             <Fingerprint className="w-8 h-8 text-purple" />
@@ -69,6 +72,36 @@ export default function TasteProfilePage() {
             Your musical identity, decoded from {profile.track_count} tracks across {profile.playlist_count} playlists
           </p>
         </div>
+        <button
+          onClick={async () => {
+            setSharing(true)
+            try {
+              const { share_url } = await getProfileShareLink()
+              await navigator.clipboard.writeText(share_url)
+              setCopied(true)
+              setTimeout(() => setCopied(false), 2500)
+            } catch {
+              // fallback: ignore
+            } finally {
+              setSharing(false)
+            }
+          }}
+          disabled={sharing}
+          className="flex items-center gap-2 px-4 py-2.5 rounded-xl bg-purple text-white font-semibold text-sm hover:bg-purple-dark transition-colors flex-shrink-0 disabled:opacity-60"
+        >
+          {copied ? (
+            <>
+              <Check className="w-4 h-4" />
+              Copied!
+            </>
+          ) : (
+            <>
+              <Share2 className="w-4 h-4" />
+              Share My Taste
+            </>
+          )}
+        </button>
+      </div>
 
       {/* Listening Personality */}
       <div className="bg-gradient-to-br from-purple to-purple-dark rounded-2xl p-8 text-white">