diff --git a/src/app/admin/page.tsx b/src/app/admin/page.tsx
index d271b33..99a6fca 100644
--- a/src/app/admin/page.tsx
+++ b/src/app/admin/page.tsx
@@ -4,6 +4,7 @@ import { useEffect, useState } from 'react';
 import Link from 'next/link';
 import AutoTextarea from '@/components/AutoTextarea';
 import { StorageSessionPrompt } from '@/components/StorageSessionPrompt';
+import { StorageConfigurationPrompt } from '@/components/StorageConfigurationPrompt';
 import { useToast } from '@/lib/contexts/ToastContext';
 import { useAccentColor } from '@/lib/contexts/AccentColorContext';
 import { refreshStorageSession } from '@/lib/storage/client';
@@ -30,6 +31,7 @@ export default function AdminPage() {
     const [isUploadingBanner, setIsUploadingBanner] = useState(false);
     const [bannerUploadError, setBannerUploadError] = useState<string | null>(null);
     const [showBannerSessionPrompt, setShowBannerSessionPrompt] = useState(false);
+    const [showBannerStorageConfiguration, setShowBannerStorageConfiguration] = useState(false);
     const [pendingBannerFile, setPendingBannerFile] = useState<File | null>(null);
     const [bannerPassword, setBannerPassword] = useState('');
     const [bannerPromptError, setBannerPromptError] = useState('');
@@ -112,6 +114,11 @@ export default function AdminPage() {
             const data = await res.json();
 
             if (!res.ok || !data.url) {
+                if (data.code === 'STORAGE_NOT_CONFIGURED' && allowPrompt) {
+                    setPendingBannerFile(file);
+                    setShowBannerStorageConfiguration(true);
+                    return;
+                }
                 if (res.status === 401 && allowPrompt) {
                     setPendingBannerFile(file);
                     setBannerPromptError('');
@@ -607,6 +614,17 @@ export default function AdminPage() {
                 onSubmit={handleBannerSessionSubmit}
                 onCancel={handleBannerSessionCancel}
             />
+            <StorageConfigurationPrompt
+                open={showBannerStorageConfiguration}
+                onConfigured={async () => {
+                    setShowBannerStorageConfiguration(false);
+                    if (pendingBannerFile) await uploadBannerFile(pendingBannerFile, false);
+                }}
+                onCancel={() => {
+                    setShowBannerStorageConfiguration(false);
+                    setPendingBannerFile(null);
+                }}
+            />
         </>
     );
 }
diff --git a/src/app/api/auth/register/route.ts b/src/app/api/auth/register/route.ts
index a0d96b9..63b2aa9 100644
--- a/src/app/api/auth/register/route.ts
+++ b/src/app/api/auth/register/route.ts
@@ -1,10 +1,8 @@
 import { NextResponse } from 'next/server';
 import { registerUser, createSession } from '@/lib/auth';
-import { createStorageSession } from '@/lib/storage/session';
-import { db, nodes, users } from '@/db';
+import { db, users } from '@/db';
 import { eq } from 'drizzle-orm';
 import { verifyTurnstileToken } from '@/lib/turnstile';
-import { testS3Credentials } from '@/lib/storage/s3';
 import { z } from 'zod';
 
 const registerSchema = z.object({
@@ -13,14 +11,6 @@ const registerSchema = z.object({
     password: z.string().min(8),
     displayName: z.string().optional(),
     turnstileToken: z.string().nullable().optional(),
-    // S3-compatible storage credentials
-    storageProvider: z.string().min(1),
-    storageEndpoint: z.string().nullable().optional(),
-    storagePublicBaseUrl: z.string().nullable().optional(),
-    storageRegion: z.string().min(1),
-    storageBucket: z.string().min(1),
-    storageAccessKey: z.string().min(10),
-    storageSecretKey: z.string().min(10),
 });
 
 export async function POST(request: Request) {
@@ -28,8 +18,7 @@ export async function POST(request: Request) {
         const body = await request.json();
 
         // Log registration attempt (excluding password)
-        const { password, ...logData } = body;
-        console.log('Registration attempt details:', logData);
+        console.log('Registration attempt:', { handle: body.handle, email: body.email });
 
         const data = registerSchema.parse(body);
 
@@ -46,38 +35,11 @@ export async function POST(request: Request) {
             }
         }
 
-        // Test S3 credentials before creating account
-        console.log('[Register] Testing S3 credentials...');
-        const s3Test = await testS3Credentials(
-            data.storageEndpoint || null,
-            data.storageRegion,
-            data.storageBucket,
-            data.storageAccessKey,
-            data.storageSecretKey
-        );
-
-        if (!s3Test.success) {
-            console.error('[Register] S3 credential test failed:', s3Test.error);
-            return NextResponse.json(
-                { error: `Storage connection failed: ${s3Test.error}` },
-                { status: 400 }
-            );
-        }
-
-        console.log('[Register] S3 credentials verified successfully');
-
         const user = await registerUser(
             data.handle,
             data.email,
             data.password,
-            data.displayName,
-            data.storageProvider,
-            data.storageEndpoint || null,
-            data.storagePublicBaseUrl || null,
-            data.storageRegion,
-            data.storageBucket,
-            data.storageAccessKey,
-            data.storageSecretKey
+            data.displayName
         );
 
         // Check if this is an NSFW node and auto-enable NSFW settings
@@ -98,7 +60,6 @@ export async function POST(request: Request) {
 
         // Create session for new user
         await createSession(user.id);
-        await createStorageSession(user, data.password);
 
         return NextResponse.json({
             success: true,
diff --git a/src/app/api/media/upload/route.ts b/src/app/api/media/upload/route.ts
index 242b47f..63e6376 100644
--- a/src/app/api/media/upload/route.ts
+++ b/src/app/api/media/upload/route.ts
@@ -44,8 +44,9 @@ export async function POST(req: NextRequest) {
         // Check if user has S3 storage configured
         if (!user.storageProvider || !user.storageAccessKeyEncrypted || !user.storageSecretKeyEncrypted) {
             return NextResponse.json({ 
-                error: 'Storage not configured. Please set up S3-compatible storage in your settings.'
-            }, { status: 400 });
+                error: 'Connect your storage before uploading media.',
+                code: 'STORAGE_NOT_CONFIGURED',
+            }, { status: 409 });
         }
 
         const storageSession =
diff --git a/src/app/api/storage/configuration/route.ts b/src/app/api/storage/configuration/route.ts
new file mode 100644
index 0000000..c77c854
--- /dev/null
+++ b/src/app/api/storage/configuration/route.ts
@@ -0,0 +1,73 @@
+import { NextResponse } from 'next/server';
+import { eq } from 'drizzle-orm';
+import { z } from 'zod';
+import { db, users } from '@/db';
+import { requireAuth, verifyPassword } from '@/lib/auth';
+import { encryptPrivateKey, serializeEncryptedKey } from '@/lib/crypto/private-key';
+import { testS3Credentials, type StorageProvider } from '@/lib/storage/s3';
+import { createStorageSession } from '@/lib/storage/session';
+
+const configurationSchema = z.object({
+  password: z.string().min(1),
+  provider: z.enum(['s3', 'r2', 'b2', 'wasabi', 'contabo']),
+  endpoint: z.string().trim().nullable().optional(),
+  publicBaseUrl: z.string().trim().nullable().optional(),
+  region: z.string().trim().min(2),
+  bucket: z.string().trim().min(3),
+  accessKey: z.string().min(10),
+  secretKey: z.string().min(10),
+});
+
+export async function POST(request: Request) {
+  try {
+    const user = await requireAuth();
+    const data = configurationSchema.parse(await request.json());
+
+    if (!user.passwordHash || !(await verifyPassword(data.password, user.passwordHash))) {
+      return NextResponse.json({ error: 'Incorrect account password' }, { status: 401 });
+    }
+
+    const storageTest = await testS3Credentials(
+      data.endpoint || null,
+      data.region,
+      data.bucket,
+      data.accessKey,
+      data.secretKey
+    );
+
+    if (!storageTest.success) {
+      return NextResponse.json(
+        { error: `Storage connection failed: ${storageTest.error}` },
+        { status: 400 }
+      );
+    }
+
+    const storageProvider = data.provider as StorageProvider;
+    const storageAccessKeyEncrypted = serializeEncryptedKey(encryptPrivateKey(data.accessKey, data.password));
+    const storageSecretKeyEncrypted = serializeEncryptedKey(encryptPrivateKey(data.secretKey, data.password));
+    const storageValues = {
+      storageProvider,
+      storageEndpoint: data.endpoint || null,
+      storagePublicBaseUrl: data.publicBaseUrl || null,
+      storageRegion: data.region,
+      storageBucket: data.bucket,
+      storageAccessKeyEncrypted,
+      storageSecretKeyEncrypted,
+    };
+
+    await db.update(users).set(storageValues).where(eq(users.id, user.id));
+    await createStorageSession({ ...user, ...storageValues }, data.password);
+
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    if (error instanceof z.ZodError) {
+      return NextResponse.json({ error: 'Invalid storage configuration', details: error.issues }, { status: 400 });
+    }
+    if (error instanceof Error && error.message === 'Authentication required') {
+      return NextResponse.json({ error: 'Authentication required' }, { status: 401 });
+    }
+
+    console.error('Storage configuration error:', error);
+    return NextResponse.json({ error: 'Failed to configure storage' }, { status: 500 });
+  }
+}
diff --git a/src/app/login/page.tsx b/src/app/login/page.tsx
index e81774d..ca848f3 100644
--- a/src/app/login/page.tsx
+++ b/src/app/login/page.tsx
@@ -38,13 +38,6 @@ export function AuthScreen({ modal = false, onClose, onSuccess }: AuthScreenProp
     const [confirmPassword, setConfirmPassword] = useState('');
     const [handle, setHandle] = useState('');
     const [displayName, setDisplayName] = useState('');
-    const [storageProvider, setStorageProvider] = useState('r2');
-    const [storageEndpoint, setStorageEndpoint] = useState('');
-    const [storagePublicBaseUrl, setStoragePublicBaseUrl] = useState('');
-    const [storageRegion, setStorageRegion] = useState('auto');
-    const [storageBucket, setStorageBucket] = useState('');
-    const [storageAccessKey, setStorageAccessKey] = useState('');
-    const [storageSecretKey, setStorageSecretKey] = useState('');
     const [error, setError] = useState('');
     const [loading, setLoading] = useState(false);
     const [nodeInfoLoaded, setNodeInfoLoaded] = useState(false);
@@ -262,13 +255,6 @@ export function AuthScreen({ modal = false, onClose, onSuccess }: AuthScreenProp
                     password,
                     handle,
                     displayName,
-                    storageProvider,
-                    storageEndpoint: storageEndpoint || null,
-                    storagePublicBaseUrl: storagePublicBaseUrl || null,
-                    storageRegion,
-                    storageBucket,
-                    storageAccessKey,
-                    storageSecretKey,
                     ...(nodeInfo.turnstileSiteKey ? { turnstileToken } : {})
                 };
 
@@ -565,8 +551,7 @@ export function AuthScreen({ modal = false, onClose, onSuccess }: AuthScreenProp
                                     </div>
                                 </div>
 
-                                {/* Row 3: Email | Storage Provider */}
-                                <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: '16px', marginBottom: '16px' }}>
+                                <div style={{ marginBottom: '16px' }}>
                                     <div>
                                         <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
                                             Email
@@ -580,159 +565,11 @@ export function AuthScreen({ modal = false, onClose, onSuccess }: AuthScreenProp
                                             required
                                         />
                                     </div>
-                                    <div>
-                                        <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
-                                            Storage Provider
-                                        </label>
-                                        <select
-                                            className="input"
-                                            value={storageProvider}
-                                            onChange={(e) => setStorageProvider(e.target.value)}
-                                            style={{ cursor: 'pointer' }}
-                                        >
-                                            <option value="r2">Cloudflare R2 (10GB free)</option>
-                                            <option value="b2">Backblaze B2 (10GB free)</option>
-                                            <option value="wasabi">Wasabi</option>
-                                            <option value="contabo">Contabo S3</option>
-                                            <option value="s3">AWS S3</option>
-                                        </select>
-                                    </div>
                                 </div>
 
-                                {/* Storage Explainer Section */}
-                                <div style={{
-                                    marginBottom: '20px',
-                                    padding: '16px',
-                                    background: 'var(--background-secondary)',
-                                    border: '1px solid var(--border)',
-                                    borderRadius: 'var(--radius-md)',
-                                }}>
-                                    <div style={{ fontSize: '14px', fontWeight: 600, marginBottom: '12px', color: 'var(--foreground)' }}>
-                                        🗄️ Why do I need to provide storage?
-                                    </div>
-                                    <div style={{ fontSize: '13px', color: 'var(--foreground-secondary)', lineHeight: 1.5, marginBottom: '12px' }}>
-                                        Synapsis is <strong>decentralized</strong> — unlike other platforms, we don't store your photos, videos, or files on our servers. 
-                                        Instead, you connect your own S3-compatible storage bucket (like Cloudflare R2 or Backblaze B2) where your media lives.
-                                    </div>
-                                    <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(200px, 1fr))', gap: '12px' }}>
-                                        <div style={{ fontSize: '12px', color: 'var(--foreground-tertiary)' }}>
-                                            <strong style={{ color: 'var(--success)' }}>✓ You own your data</strong><br/>
-                                            Your files stay in your bucket, not ours
-                                        </div>
-                                        <div style={{ fontSize: '12px', color: 'var(--foreground-tertiary)' }}>
-                                            <strong style={{ color: 'var(--success)' }}>✓ Portable</strong><br/>
-                                            Take your media with you if you leave
-                                        </div>
-                                        <div style={{ fontSize: '12px', color: 'var(--foreground-tertiary)' }}>
-                                            <strong style={{ color: 'var(--success)' }}>✓ Free options</strong><br/>
-                                            R2 and B2 offer 10GB free
-                                        </div>
-                                    </div>
-                                </div>
-
-                                {/* Endpoint URL - only show for providers that need it (R2, B2, Contabo) */}
-                                {(storageProvider === 'r2' || storageProvider === 'b2' || storageProvider === 'contabo') && (
-                                    <div style={{ marginBottom: '16px' }}>
-                                        <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
-                                            Endpoint URL
-                                        </label>
-                                        <input
-                                            type="text"
-                                            className="input"
-                                            value={storageEndpoint}
-                                            onChange={(e) => setStorageEndpoint(e.target.value)}
-                                            placeholder={storageProvider === 'contabo' ? 'https://s3.eu2.contabo.com' : 'https://<account>.r2.cloudflarestorage.com'}
-                                            required
-                                        />
-                                        <div style={{ fontSize: '11px', color: 'var(--foreground-tertiary)', marginTop: '4px' }}>
-                                            {storageProvider === 'contabo' ? 'S3 API endpoint from Contabo dashboard (e.g., https://s3.eu2.contabo.com)' :
-                                             'S3-compatible endpoint URL for uploads.'}
-                                        </div>
-                                    </div>
-                                )}
-
-                                {/* Public Base URL - only show for providers that need it (R2, B2, Contabo) */}
-                                {(storageProvider === 'r2' || storageProvider === 'b2' || storageProvider === 'contabo') && (
-                                    <div style={{ marginBottom: '16px' }}>
-                                        <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
-                                            Public Base URL
-                                        </label>
-                                        <input
-                                            type="text"
-                                            className="input"
-                                            value={storagePublicBaseUrl}
-                                            onChange={(e) => setStoragePublicBaseUrl(e.target.value)}
-                                            placeholder={storageProvider === 'contabo' ? 'https://usc1.contabostorage.com/d5bec82ae49b444d8314dcb13654dd1d:your-bucket' : 'https://pub-xxx.r2.dev'}
-                                            required
-                                        />
-                                        <div style={{ fontSize: '11px', color: 'var(--foreground-tertiary)', marginTop: '4px' }}>
-                                            {storageProvider === 'contabo' ? 'Public URL from Contabo (format: https://region.contabostorage.com/account-id:bucket)' :
-                                             storageProvider === 'r2' ? 'Public bucket URL from R2 dashboard (e.g., https://pub-xxx.r2.dev)' :
-                                             storageProvider === 'b2' ? 'Public bucket URL from B2 dashboard (e.g., https://f000.backblazeb2.com/file/bucket)' :
-                                             'Public URL where files are accessible (without trailing slash)'}
-                                        </div>
-                                    </div>
-                                )}
-
-                                <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: '16px', marginBottom: '16px' }}>
-                                    <div>
-                                        <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
-                                            Region
-                                        </label>
-                                        <input
-                                            type="text"
-                                            className="input"
-                                            value={storageRegion}
-                                            onChange={(e) => setStorageRegion(e.target.value)}
-                                            placeholder="auto"
-                                            required
-                                        />
-                                    </div>
-                                    <div>
-                                        <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
-                                            Bucket Name
-                                        </label>
-                                        <input
-                                            type="text"
-                                            className="input"
-                                            value={storageBucket}
-                                            onChange={(e) => setStorageBucket(e.target.value)}
-                                            placeholder="my-synapsis-bucket"
-                                            required
-                                        />
-                                    </div>
-                                </div>
-
-                                <div style={{ marginBottom: '16px' }}>
-                                    <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
-                                        Access Key ID
-                                    </label>
-                                    <input
-                                        type="password"
-                                        className="input"
-                                        value={storageAccessKey}
-                                        onChange={(e) => setStorageAccessKey(e.target.value)}
-                                        placeholder="AKIA..."
-                                        required
-                                    />
-                                </div>
-
-                                <div style={{ marginBottom: '16px' }}>
-                                    <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
-                                        Secret Access Key
-                                    </label>
-                                    <input
-                                        type="password"
-                                        className="input"
-                                        value={storageSecretKey}
-                                        onChange={(e) => setStorageSecretKey(e.target.value)}
-                                        placeholder="••••••••"
-                                        required
-                                    />
-                                    <div style={{ fontSize: '12px', color: 'var(--foreground-tertiary)', marginTop: '4px' }}>
-                                        Get free S3 storage at <a href="https://dash.cloudflare.com/sign-up/r2" target="_blank" rel="noopener noreferrer" style={{ color: 'var(--accent)' }}>Cloudflare R2</a> (10GB free) or <a href="https://www.backblaze.com/b2/sign-up.html" target="_blank" rel="noopener noreferrer" style={{ color: 'var(--accent)' }}>Backblaze B2</a>
-                                    </div>
-                                </div>
+                                <p style={{ fontSize: '12px', color: 'var(--foreground-tertiary)', marginBottom: '16px' }}>
+                                    You can connect your own S3-compatible storage when you first upload media.
+                                </p>
                             </>
                         )}
 
@@ -812,11 +649,6 @@ export function AuthScreen({ modal = false, onClose, onSuccess }: AuthScreenProp
                                     !password || password.length < 8 ||
                                     !confirmPassword ||
                                     password !== confirmPassword ||
-                                    !storageProvider ||
-                                    !storageRegion ||
-                                    !storageBucket ||
-                                    !storageAccessKey ||
-                                    !storageSecretKey ||
                                     (nodeInfo.isNsfw && !ageVerified)
                                 ))}
                         >
@@ -882,8 +714,12 @@ export function AuthScreen({ modal = false, onClose, onSuccess }: AuthScreenProp
                                         Browse
                                     </span>
                                 </label>
-                            </div>
-                        </div>
+                                    </div>
+                                </div>
+
+                                <p style={{ fontSize: '12px', color: 'var(--foreground-tertiary)', marginBottom: '16px' }}>
+                                    You can connect your own S3-compatible storage when you first upload media.
+                                </p>
 
                         <div style={{ marginBottom: '16px' }}>
                             <label style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>
diff --git a/src/components/Compose.tsx b/src/components/Compose.tsx
index 1e19c93..62be04f 100644
--- a/src/components/Compose.tsx
+++ b/src/components/Compose.tsx
@@ -7,6 +7,7 @@ import { ImageIcon, AlertTriangle, Film } from 'lucide-react';
 import { VideoEmbed } from '@/components/VideoEmbed';
 import { useFormattedHandle } from '@/lib/utils/handle';
 import { useAuth } from '@/lib/contexts/AuthContext';
+import { StorageConfigurationPrompt } from '@/components/StorageConfigurationPrompt';
 
 interface MediaAttachment extends Attachment {
     mimeType?: string;
@@ -28,6 +29,8 @@ export function Compose({ onPost, replyingTo, onCancelReply, placeholder = "What
     const [attachments, setAttachments] = useState<MediaAttachment[]>([]);
     const [isUploading, setIsUploading] = useState(false);
     const [uploadError, setUploadError] = useState<string | null>(null);
+    const [pendingStorageFiles, setPendingStorageFiles] = useState<File[]>([]);
+    const [showStorageConfiguration, setShowStorageConfiguration] = useState(false);
     const [linkPreview, setLinkPreview] = useState<any>(null);
     const [fetchingPreview, setFetchingPreview] = useState(false);
     const [lastDetectedUrl, setLastDetectedUrl] = useState<string | null>(null);
@@ -116,11 +119,7 @@ export function Compose({ onPost, replyingTo, onCancelReply, placeholder = "What
         setIsPosting(false);
     };
 
-    const handleMediaSelect = async (event: React.ChangeEvent<HTMLInputElement>) => {
-        const files = Array.from(event.target.files || []);
-        event.target.value = '';
-        if (files.length === 0) return;
-
+    const uploadMediaFiles = async (files: File[]) => {
         const remainingSlots = Math.max(0, 4 - attachments.length);
         const selectedFiles = files.slice(0, remainingSlots);
         if (selectedFiles.length === 0) return;
@@ -141,6 +140,12 @@ export function Compose({ onPost, replyingTo, onCancelReply, placeholder = "What
                 const data = await res.json();
 
                 if (!res.ok || !data.media?.id) {
+                    if (data.code === 'STORAGE_NOT_CONFIGURED') {
+                        setPendingStorageFiles(selectedFiles);
+                        setShowStorageConfiguration(true);
+                        setIsUploading(false);
+                        return;
+                    }
                     throw new Error(data.error || 'Upload failed');
                 }
 
@@ -160,12 +165,32 @@ export function Compose({ onPost, replyingTo, onCancelReply, placeholder = "What
         setIsUploading(false);
     };
 
+    const handleMediaSelect = async (event: React.ChangeEvent<HTMLInputElement>) => {
+        const files = Array.from(event.target.files || []);
+        event.target.value = '';
+        if (files.length === 0) return;
+        await uploadMediaFiles(files);
+    };
+
     const handleRemoveAttachment = (id: string) => {
         setAttachments((prev) => prev.filter((item) => item.id !== id));
     };
 
     return (
         <div className={`compose ${isReply ? 'reply-compose' : ''}`}>
+            <StorageConfigurationPrompt
+                open={showStorageConfiguration}
+                onConfigured={async () => {
+                    setShowStorageConfiguration(false);
+                    const files = pendingStorageFiles;
+                    setPendingStorageFiles([]);
+                    await uploadMediaFiles(files);
+                }}
+                onCancel={() => {
+                    setShowStorageConfiguration(false);
+                    setPendingStorageFiles([]);
+                }}
+            />
             {replyingTo && !isReply && (
                 <div className="compose-reply-target">
                     <div className="compose-reply-info">
diff --git a/src/components/StorageConfigurationPrompt.tsx b/src/components/StorageConfigurationPrompt.tsx
new file mode 100644
index 0000000..5da9ebb
--- /dev/null
+++ b/src/components/StorageConfigurationPrompt.tsx
@@ -0,0 +1,145 @@
+'use client';
+
+import { useState } from 'react';
+
+interface StorageConfigurationPromptProps {
+    open: boolean;
+    onConfigured: () => void | Promise<void>;
+    onCancel: () => void;
+}
+
+export function StorageConfigurationPrompt({
+    open,
+    onConfigured,
+    onCancel,
+}: StorageConfigurationPromptProps) {
+    const [provider, setProvider] = useState('r2');
+    const [endpoint, setEndpoint] = useState('');
+    const [publicBaseUrl, setPublicBaseUrl] = useState('');
+    const [region, setRegion] = useState('auto');
+    const [bucket, setBucket] = useState('');
+    const [accessKey, setAccessKey] = useState('');
+    const [secretKey, setSecretKey] = useState('');
+    const [password, setPassword] = useState('');
+    const [error, setError] = useState('');
+    const [isSubmitting, setIsSubmitting] = useState(false);
+
+    if (!open) return null;
+
+    const needsCustomUrls = provider === 'r2' || provider === 'b2' || provider === 'contabo';
+
+    const handleSubmit = async (event: React.FormEvent<HTMLFormElement>) => {
+        event.preventDefault();
+        setError('');
+        setIsSubmitting(true);
+
+        try {
+            const response = await fetch('/api/storage/configuration', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({
+                    provider,
+                    endpoint: endpoint || null,
+                    publicBaseUrl: publicBaseUrl || null,
+                    region,
+                    bucket,
+                    accessKey,
+                    secretKey,
+                    password,
+                }),
+            });
+            const data = await response.json().catch(() => ({}));
+
+            if (!response.ok) {
+                throw new Error(data.error || 'Failed to connect storage');
+            }
+
+            await onConfigured();
+        } catch (submitError) {
+            setError(submitError instanceof Error ? submitError.message : 'Failed to connect storage');
+        } finally {
+            setIsSubmitting(false);
+        }
+    };
+
+    return (
+        <div
+            style={{
+                position: 'fixed',
+                inset: 0,
+                zIndex: 100000,
+                display: 'flex',
+                alignItems: 'center',
+                justifyContent: 'center',
+                padding: '20px',
+                background: 'rgba(0, 0, 0, 0.8)',
+            }}
+            onClick={onCancel}
+        >
+            <div className="card" style={{ width: '100%', maxWidth: '560px', maxHeight: '90vh', overflowY: 'auto', padding: '24px' }} onClick={(event) => event.stopPropagation()}>
+                <h3 style={{ fontSize: '20px', fontWeight: 600, marginBottom: '8px' }}>Connect your media storage</h3>
+                <p style={{ color: 'var(--foreground-secondary)', lineHeight: 1.5, marginBottom: '20px' }}>
+                    Synapsis keeps media in your own S3-compatible bucket. This is only required when you upload a photo or video.
+                </p>
+
+                <form onSubmit={handleSubmit}>
+                    <label style={{ display: 'block', marginBottom: '12px' }}>
+                        <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>Provider</span>
+                        <select className="input" value={provider} onChange={(event) => setProvider(event.target.value)}>
+                            <option value="r2">Cloudflare R2</option>
+                            <option value="b2">Backblaze B2</option>
+                            <option value="wasabi">Wasabi</option>
+                            <option value="contabo">Contabo S3</option>
+                            <option value="s3">AWS S3</option>
+                        </select>
+                    </label>
+
+                    {needsCustomUrls && (
+                        <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: '12px' }}>
+                            <label style={{ display: 'block', marginBottom: '12px' }}>
+                                <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>S3 endpoint</span>
+                                <input className="input" value={endpoint} onChange={(event) => setEndpoint(event.target.value)} placeholder="https://..." required />
+                            </label>
+                            <label style={{ display: 'block', marginBottom: '12px' }}>
+                                <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>Public media URL</span>
+                                <input className="input" value={publicBaseUrl} onChange={(event) => setPublicBaseUrl(event.target.value)} placeholder="https://..." required />
+                            </label>
+                        </div>
+                    )}
+
+                    <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: '12px' }}>
+                        <label style={{ display: 'block', marginBottom: '12px' }}>
+                            <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>Region</span>
+                            <input className="input" value={region} onChange={(event) => setRegion(event.target.value)} required />
+                        </label>
+                        <label style={{ display: 'block', marginBottom: '12px' }}>
+                            <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>Bucket</span>
+                            <input className="input" value={bucket} onChange={(event) => setBucket(event.target.value)} required />
+                        </label>
+                    </div>
+
+                    <label style={{ display: 'block', marginBottom: '12px' }}>
+                        <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>Access key ID</span>
+                        <input className="input" type="password" value={accessKey} onChange={(event) => setAccessKey(event.target.value)} required minLength={10} />
+                    </label>
+                    <label style={{ display: 'block', marginBottom: '12px' }}>
+                        <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>Secret access key</span>
+                        <input className="input" type="password" value={secretKey} onChange={(event) => setSecretKey(event.target.value)} required minLength={10} />
+                    </label>
+                    <label style={{ display: 'block', marginBottom: '12px' }}>
+                        <span style={{ display: 'block', marginBottom: '6px', fontSize: '14px', fontWeight: 500 }}>Synapsis account password</span>
+                        <input className="input" type="password" value={password} onChange={(event) => setPassword(event.target.value)} required />
+                        <span style={{ display: 'block', marginTop: '5px', fontSize: '12px', color: 'var(--foreground-tertiary)' }}>Used locally to encrypt these credentials before they are saved.</span>
+                    </label>
+
+                    {error && <div style={{ color: 'var(--error)', fontSize: '13px', marginBottom: '12px' }}>{error}</div>}
+
+                    <div style={{ display: 'flex', justifyContent: 'flex-end', gap: '12px' }}>
+                        <button type="button" className="btn btn-ghost" onClick={onCancel} disabled={isSubmitting}>Cancel</button>
+                        <button type="submit" className="btn btn-primary" disabled={isSubmitting}>{isSubmitting ? 'Connecting...' : 'Connect and upload'}</button>
+                    </div>
+                </form>
+            </div>
+        </div>
+    );
+}
diff --git a/src/components/UserStorageImageUpload.tsx b/src/components/UserStorageImageUpload.tsx
index 99a678a..b3c610e 100644
--- a/src/components/UserStorageImageUpload.tsx
+++ b/src/components/UserStorageImageUpload.tsx
@@ -2,6 +2,7 @@
 
 import { useRef, useState } from 'react';
 import { StorageSessionPrompt } from '@/components/StorageSessionPrompt';
+import { StorageConfigurationPrompt } from '@/components/StorageConfigurationPrompt';
 import { refreshStorageSession } from '@/lib/storage/client';
 
 interface UserStorageImageUploadProps {
@@ -28,6 +29,7 @@ export function UserStorageImageUpload({
     const inputRef = useRef<HTMLInputElement>(null);
     const [isUploading, setIsUploading] = useState(false);
     const [showSessionPrompt, setShowSessionPrompt] = useState(false);
+    const [showConfigurationPrompt, setShowConfigurationPrompt] = useState(false);
     const [pendingFile, setPendingFile] = useState<File | null>(null);
     const [password, setPassword] = useState('');
     const [promptError, setPromptError] = useState('');
@@ -55,6 +57,12 @@ export function UserStorageImageUpload({
             if (!res.ok || !data.url) {
                 const message = data.error || 'Upload failed';
 
+                if (data.code === 'STORAGE_NOT_CONFIGURED' && allowPrompt) {
+                    setPendingFile(file);
+                    setShowConfigurationPrompt(true);
+                    return;
+                }
+
                 if (res.status === 401 && allowPrompt) {
                     setPendingFile(file);
                     setPromptError('');
@@ -188,6 +196,18 @@ export function UserStorageImageUpload({
                 onSubmit={handlePromptSubmit}
                 onCancel={handlePromptCancel}
             />
+            <StorageConfigurationPrompt
+                open={showConfigurationPrompt}
+                onConfigured={async () => {
+                    setShowConfigurationPrompt(false);
+                    if (pendingFile) await uploadFile(pendingFile, false);
+                }}
+                onCancel={() => {
+                    setShowConfigurationPrompt(false);
+                    setPendingFile(null);
+                    resetFileInput();
+                }}
+            />
         </>
     );
 }
diff --git a/src/db/schema.ts b/src/db/schema.ts
index ee30b16..e7c4a11 100644
--- a/src/db/schema.ts
+++ b/src/db/schema.ts
@@ -67,7 +67,7 @@ export const users = sqliteTable('users', {
   movedTo: text('moved_to'), // New actor URL if this account migrated away
   movedFrom: text('moved_from'), // Old actor URL if this account migrated here
   migratedAt: integer('migrated_at', { mode: 'timestamp' }), // When the migration occurred
-  // User-owned S3-compatible storage - required for new users
+  // Optional user-owned S3-compatible storage, configured on first media upload
   storageProvider: text('storage_provider'), // 's3', 'r2', 'b2', 'wasabi', 'contabo'
   storageEndpoint: text('storage_endpoint'), // S3 endpoint URL (optional for AWS)
   storagePublicBaseUrl: text('storage_public_base_url'), // Public URL for viewing files (required for R2, B2, Contabo)
diff --git a/src/lib/auth/index.ts b/src/lib/auth/index.ts
index 2b2b109..84a82ed 100644
--- a/src/lib/auth/index.ts
+++ b/src/lib/auth/index.ts
@@ -11,7 +11,6 @@ import { encryptPrivateKey, serializeEncryptedKey } from '@/lib/crypto/private-k
 import { base58btc } from 'multiformats/bases/base58';
 import { cookies } from 'next/headers';
 import { upsertHandleEntries } from '@/lib/federation/handles';
-import { generateAndUploadAvatarToUserStorage } from '@/lib/storage/s3';
 
 const ACTIVE_SESSION_COOKIE_NAME = 'synapsis_session';
 const SESSION_COOKIE_NAME = 'synapsis_sessions';
@@ -280,14 +279,7 @@ export async function registerUser(
     handle: string,
     email: string,
     password: string,
-    displayName?: string,
-    storageProvider?: string,
-    storageEndpoint?: string | null,
-    storagePublicBaseUrl?: string | null,
-    storageRegion?: string,
-    storageBucket?: string,
-    storageAccessKey?: string,
-    storageSecretKey?: string
+    displayName?: string
 ): Promise<typeof users.$inferSelect> {
     // Validate handle format
     if (!/^[a-zA-Z0-9_]{3,20}$/.test(handle)) {
@@ -312,23 +304,6 @@ export async function registerUser(
         throw new Error('Email is already registered');
     }
 
-    // Validate S3 storage credentials (required for new users)
-    if (!storageProvider) {
-        throw new Error('Storage provider is required.');
-    }
-    if (!storageRegion || storageRegion.length < 2) {
-        throw new Error('Storage region is required (e.g., us-east-1, auto).');
-    }
-    if (!storageBucket || storageBucket.length < 3) {
-        throw new Error('Storage bucket name is required.');
-    }
-    if (!storageAccessKey || storageAccessKey.length < 10) {
-        throw new Error('Storage access key is required.');
-    }
-    if (!storageSecretKey || storageSecretKey.length < 10) {
-        throw new Error('Storage secret key is required.');
-    }
-
     // Generate cryptographic keys
     const { publicKey, privateKey } = await generateKeyPair();
 
@@ -341,38 +316,14 @@ export async function registerUser(
 
     const nodeDomain = process.env.NEXT_PUBLIC_NODE_DOMAIN || 'localhost:43821';
 
-    // Generate avatar and upload to user's S3 storage
-    const fullHandle = `${handle.toLowerCase()}@${nodeDomain}`;
-    const avatarUrl = await generateAndUploadAvatarToUserStorage(
-        fullHandle,
-        storageEndpoint || undefined,
-        storagePublicBaseUrl || undefined,
-        storageRegion,
-        storageBucket,
-        storageAccessKey,
-        storageSecretKey
-    );
-
-    // Encrypt the storage credentials with user's password
-    const encryptedAccessKey = encryptPrivateKey(storageAccessKey, password);
-    const encryptedSecretKey = encryptPrivateKey(storageSecretKey, password);
-
     const [user] = await db.insert(users).values({
         did,
         handle: handle.toLowerCase(),
         email: email.toLowerCase(),
         passwordHash,
         displayName: displayName || handle,
-        avatarUrl,
         publicKey,
         privateKeyEncrypted: serializeEncryptedKey(encryptedPrivateKey),
-        storageProvider,
-        storageEndpoint: storageEndpoint || null,
-        storagePublicBaseUrl: storagePublicBaseUrl || null,
-        storageRegion,
-        storageBucket,
-        storageAccessKeyEncrypted: serializeEncryptedKey(encryptedAccessKey),
-        storageSecretKeyEncrypted: serializeEncryptedKey(encryptedSecretKey),
     }).returning();
 
     await upsertHandleEntries([{