diff --git a/css/components.css b/css/components.css
index fa55358..5210829 100644
--- a/css/components.css
+++ b/css/components.css
@@ -265,6 +265,26 @@ app-header .btn-profile {
     border-radius: var(--radius-md);
 }
 
+app-header .btn-profile-avatar {
+    padding: 0;
+    width: 36px;
+    height: 36px;
+    border-radius: var(--radius-full);
+    overflow: hidden;
+    border: 2px solid var(--color-border);
+    transition: border-color var(--transition-fast);
+}
+
+app-header .btn-profile-avatar:hover {
+    border-color: var(--color-accent);
+}
+
+app-header .btn-profile-avatar svg {
+    width: 32px;
+    height: 32px;
+    display: block;
+}
+
 app-header .btn-login-text,
 app-header .btn-profile-text {
     display: inline;
diff --git a/js/components/app-header.js b/js/components/app-header.js
index e02d215..429e0ef 100644
--- a/js/components/app-header.js
+++ b/js/components/app-header.js
@@ -2,6 +2,7 @@ import { i18n, t } from '../i18n.js'
 import { router } from '../router.js'
 import { auth } from '../services/auth.js'
 import { notificationsService } from '../services/notifications.js'
+import { generateAvatar } from '../services/identity.js'
 
 class AppHeader extends HTMLElement {
     constructor() {
@@ -188,17 +189,18 @@ class AppHeader extends HTMLElement {
                         </a>
                         <div class="dropdown" id="profile-dropdown">
                             <button 
-                                class="btn btn-icon btn-outline" 
+                                class="btn btn-icon btn-profile-avatar" 
                                 id="profile-toggle"
                                 aria-haspopup="menu"
                                 aria-expanded="${this.profileDropdownOpen}"
                                 aria-label="${t('header.profile')}"
                                 title="${t('header.profile')}"
                             >
+                                ${auth.currentUser?.id ? generateAvatar(auth.currentUser.id, 32) : `
                                 <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
                                     <path d="M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2"></path>
                                     <circle cx="12" cy="7" r="4"></circle>
-                                </svg>
+                                </svg>`}
                             </button>
                             <div class="dropdown-menu dropdown-menu-right" role="menu">
                                 <a href="#/my-listings" class="dropdown-item" role="menuitem">
diff --git a/js/components/pages/page-listing.js b/js/components/pages/page-listing.js
index d70fa68..825e66a 100644
--- a/js/components/pages/page-listing.js
+++ b/js/components/pages/page-listing.js
@@ -9,6 +9,7 @@ import '../location-map.js'
 import '../listing-card.js'
 import { categoriesService } from '../../services/categories.js'
 import { reputationService } from '../../services/reputation.js'
+import { generatePseudonym, generateAvatar } from '../../services/identity.js'
 
 class PageListing extends HTMLElement {
     constructor() {
@@ -437,10 +438,10 @@ class PageListing extends HTMLElement {
             <!-- Seller Card -->
             <div class="sidebar-card seller-card">
                 <div class="seller-header">
-                    <div class="seller-avatar">?</div>
+                    <div class="seller-avatar">${this.listing?.user_created ? generateAvatar(this.listing.user_created, 48) : '?'}</div>
                     <div class="seller-info">
-                        <strong>${t('listing.anonymousSeller')}</strong>
-                        <span>${t('listing.memberSince')} 2024</span>
+                        <strong>${this.listing?.user_created ? escapeHTML(generatePseudonym(this.listing.user_created)) : t('listing.anonymousSeller')}</strong>
+                        <span class="seller-auto-label">${t('listing.autoGenerated')}</span>
                     </div>
                 </div>
                 ${this.renderSellerReputation()}
@@ -517,7 +518,7 @@ class PageListing extends HTMLElement {
                 <div class="tab-content" id="tab-chat">
                     <chat-widget
                         listing-id="${this.listing?.id || ''}"
-                        recipient-name="${t('listing.anonymousSeller')}"
+                        recipient-name="${this.listing?.user_created ? escapeHTML(generatePseudonym(this.listing.user_created)) : t('listing.anonymousSeller')}"
                         seller-public-key="${this.listing?.contact_public_key || ''}"
                     ></chat-widget>
                 </div>
@@ -980,14 +981,18 @@ style.textContent = /* css */`
     page-listing .seller-avatar {
         width: 48px;
         height: 48px;
-        border-radius: 50%;
-        background: var(--color-primary);
-        color: white;
+        border-radius: var(--radius-full);
+        overflow: hidden;
+        flex-shrink: 0;
         display: flex;
         align-items: center;
         justify-content: center;
-        font-weight: var(--font-weight-bold);
-        font-size: var(--font-size-lg);
+    }
+
+    page-listing .seller-avatar svg {
+        width: 48px;
+        height: 48px;
+        display: block;
     }
     
     page-listing .seller-info {
@@ -1000,6 +1005,12 @@ style.textContent = /* css */`
         color: var(--color-text-muted);
     }
 
+    page-listing .seller-auto-label {
+        font-size: var(--font-size-xs);
+        color: var(--color-text-muted);
+        font-style: italic;
+    }
+
     page-listing .seller-reputation {
         padding: var(--space-sm) 0 0;
         margin-top: var(--space-sm);
diff --git a/js/services/identity.js b/js/services/identity.js
new file mode 100644
index 0000000..b92625f
--- /dev/null
+++ b/js/services/identity.js
@@ -0,0 +1,80 @@
+const ADJECTIVES = [
+  'swift','calm','bold','keen','wise','warm','bright','silent','gentle','steady',
+  'clever','vivid','nimble','serene','brave','quick','subtle','sharp','lucid','agile',
+  'noble','witty','mellow','fierce','stout','deft','proud','fair','grand','cool'
+]
+
+const ANIMALS = [
+  'fox','owl','wolf','bear','lynx','hare','deer','hawk','otter','raven',
+  'crane','puma','seal','finch','cobra','bison','ibex','oriole','quail','gecko',
+  'panda','tiger','eagle','badger','moose','robin','coral','falcon','heron','viper'
+]
+
+function hashToBytes(input) {
+  const hex = input.replace(/[^0-9a-fA-F]/g, '')
+  const bytes = []
+  for (let i = 0; i < hex.length; i += 2) {
+    bytes.push(parseInt(hex.substring(i, i + 2), 16))
+  }
+  return bytes
+}
+
+export function generatePseudonym(hash) {
+  if (!hash || hash.length < 8) return 'Unknown'
+  const bytes = hashToBytes(hash)
+  const adj = ADJECTIVES[bytes[0] % ADJECTIVES.length]
+  const animal = ANIMALS[bytes[1] % ANIMALS.length]
+  const num = ((bytes[2] << 8) | bytes[3]) % 100
+  const capitalAdj = adj.charAt(0).toUpperCase() + adj.slice(1)
+  const capitalAnimal = animal.charAt(0).toUpperCase() + animal.slice(1)
+  return `${capitalAdj}${capitalAnimal}${num}`
+}
+
+export function generateAvatar(hash, size = 64) {
+  if (!hash || hash.length < 16) {
+    return `<svg xmlns="http://www.w3.org/2000/svg" width="${size}" height="${size}" viewBox="0 0 64 64">
+      <rect width="64" height="64" rx="32" fill="#A8A29E"/>
+      <text x="32" y="40" text-anchor="middle" font-family="system-ui" font-size="24" fill="#fff">?</text>
+    </svg>`
+  }
+
+  const bytes = hashToBytes(hash)
+
+  const hues = [
+    174, // teal (brand)
+    210, // blue
+    260, // purple
+    330, // pink
+    25,  // orange
+    45,  // gold
+    140, // green
+    190, // cyan
+  ]
+  const hue = hues[bytes[4] % hues.length]
+  const bg = `hsl(${hue}, 45%, 45%)`
+  const fg = `hsl(${hue}, 30%, 85%)`
+
+  const grid = 5
+  const cellSize = 64 / grid
+  let cells = ''
+
+  for (let y = 0; y < grid; y++) {
+    for (let x = 0; x < Math.ceil(grid / 2); x++) {
+      const byteIndex = (y * 3 + x + 5) % bytes.length
+      if (bytes[byteIndex] % 2 === 0) {
+        const rx = x * cellSize
+        const ry = y * cellSize
+        cells += `<rect x="${rx}" y="${ry}" width="${cellSize}" height="${cellSize}" fill="${fg}"/>`
+        const mirrorX = (grid - 1 - x) * cellSize
+        if (mirrorX !== rx) {
+          cells += `<rect x="${mirrorX}" y="${ry}" width="${cellSize}" height="${cellSize}" fill="${fg}"/>`
+        }
+      }
+    }
+  }
+
+  return `<svg xmlns="http://www.w3.org/2000/svg" width="${size}" height="${size}" viewBox="0 0 64 64">
+    <rect width="64" height="64" rx="32" fill="${bg}"/>
+    ${cells}
+  </svg>`
+}
diff --git a/locales/de.json b/locales/de.json
index dae8f6a..fcb1d59 100644
--- a/locales/de.json
+++ b/locales/de.json
@@ -86,6 +86,7 @@
     "location": "Standort",
     "seller": "Anbieter",
     "anonymousSeller": "Anonymer Anbieter",
+    "autoGenerated": "automatisch generiert",
     "memberSince": "Mitglied seit",
     "postedOn": "Eingestellt am",
     "contactSeller": "Anbieter kontaktieren",
diff --git a/locales/en.json b/locales/en.json
index bb2c700..a4c13d1 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -86,6 +86,7 @@
     "location": "Location",
     "seller": "Seller",
     "anonymousSeller": "Anonymous Seller",
+    "autoGenerated": "auto-generated",
     "memberSince": "Member since",
     "postedOn": "Posted on",
     "contactSeller": "Contact Seller",
diff --git a/locales/es.json b/locales/es.json
index 88fb6a3..188f4a2 100644
--- a/locales/es.json
+++ b/locales/es.json
@@ -86,6 +86,7 @@
     "location": "Ubicación",
     "seller": "Vendedor",
     "anonymousSeller": "Vendedor anónimo",
+    "autoGenerated": "generado automáticamente",
     "memberSince": "Miembro desde",
     "postedOn": "Publicado el",
     "contactSeller": "Contactar al vendedor",
diff --git a/locales/fr.json b/locales/fr.json
index e623d79..8da6e0f 100644
--- a/locales/fr.json
+++ b/locales/fr.json
@@ -86,6 +86,7 @@
     "location": "Emplacement",
     "seller": "Vendeur",
     "anonymousSeller": "Vendeur anonyme",
+    "autoGenerated": "généré automatiquement",
     "memberSince": "Membre depuis",
     "postedOn": "Publié le",
     "contactSeller": "Contacter le vendeur",
diff --git a/locales/it.json b/locales/it.json
index 231b417..aa9d982 100644
--- a/locales/it.json
+++ b/locales/it.json
@@ -86,6 +86,7 @@
     "location": "Località",
     "seller": "Venditore",
     "anonymousSeller": "Venditore anonimo",
+    "autoGenerated": "generato automaticamente",
     "memberSince": "Membro dal",
     "postedOn": "Pubblicato il",
     "contactSeller": "Contatta il venditore",
diff --git a/locales/pt.json b/locales/pt.json
index a0bf6a4..69b1687 100644
--- a/locales/pt.json
+++ b/locales/pt.json
@@ -86,6 +86,7 @@
     "location": "Localização",
     "seller": "Vendedor",
     "anonymousSeller": "Vendedor Anônimo",
+    "autoGenerated": "gerado automaticamente",
     "memberSince": "Membro desde",
     "postedOn": "Publicado em",
     "contactSeller": "Contatar Vendedor",
diff --git a/locales/ru.json b/locales/ru.json
index d4f48c5..4e09f84 100644
--- a/locales/ru.json
+++ b/locales/ru.json
@@ -86,6 +86,7 @@
     "location": "Местоположение",
     "seller": "Продавец",
     "anonymousSeller": "Анонимный продавец",
+    "autoGenerated": "сгенерировано автоматически",
     "memberSince": "Участник с",
     "postedOn": "Опубликовано",
     "contactSeller": "Связаться с продавцом",
diff --git a/service-worker.js b/service-worker.js
index 0d90b22..0e37b90 100644
--- a/service-worker.js
+++ b/service-worker.js
@@ -1,4 +1,4 @@
-const CACHE_NAME = 'kashilo-v51';
+const CACHE_NAME = 'kashilo-v52';
 const STATIC_ASSETS = [
     '/',
     '/index.html',
@@ -37,6 +37,7 @@ const STATIC_ASSETS = [
     '/js/services/btcpay.js',
     '/js/services/favorites.js',
     '/js/services/notifications.js',
+    '/js/services/identity.js',
 
     // Components
     '/js/components/app-shell.js',