diff --git a/db.py b/db.py
index bdbb012..a6d51d5 100644
--- a/db.py
+++ b/db.py
@@ -117,6 +117,32 @@ CREATE TABLE IF NOT EXISTS revoked_tokens (
     expires_at TIMESTAMPTZ NOT NULL
 );
 
+-- User storage providers (IPFS pinning services, local storage, etc.)
+CREATE TABLE IF NOT EXISTS user_storage (
+    id SERIAL PRIMARY KEY,
+    username VARCHAR(255) NOT NULL REFERENCES users(username),
+    provider_type VARCHAR(50) NOT NULL,  -- 'pinata', 'web3storage', 'filebase', 'local'
+    provider_name VARCHAR(255),          -- User-friendly name
+    config JSONB NOT NULL DEFAULT '{}',  -- API keys, endpoints, paths
+    capacity_gb INTEGER NOT NULL,        -- Total capacity user is contributing
+    is_active BOOLEAN DEFAULT true,
+    created_at TIMESTAMPTZ DEFAULT NOW(),
+    updated_at TIMESTAMPTZ DEFAULT NOW(),
+    UNIQUE(username, provider_type, provider_name)
+);
+
+-- Track what's stored where
+CREATE TABLE IF NOT EXISTS storage_pins (
+    id SERIAL PRIMARY KEY,
+    content_hash VARCHAR(64) NOT NULL,
+    storage_id INTEGER NOT NULL REFERENCES user_storage(id) ON DELETE CASCADE,
+    ipfs_cid VARCHAR(128),
+    pin_type VARCHAR(20) NOT NULL,  -- 'user_content', 'donated', 'system'
+    size_bytes BIGINT,
+    pinned_at TIMESTAMPTZ DEFAULT NOW(),
+    UNIQUE(content_hash, storage_id)
+);
+
 -- Indexes
 CREATE INDEX IF NOT EXISTS idx_users_created_at ON users(created_at);
 CREATE INDEX IF NOT EXISTS idx_assets_content_hash ON assets(content_hash);
@@ -129,6 +155,20 @@ CREATE INDEX IF NOT EXISTS idx_activities_anchor ON activities(anchor_root);
 CREATE INDEX IF NOT EXISTS idx_anchors_created ON anchors(created_at DESC);
 CREATE INDEX IF NOT EXISTS idx_followers_username ON followers(username);
 CREATE INDEX IF NOT EXISTS idx_revoked_tokens_expires ON revoked_tokens(expires_at);
+CREATE INDEX IF NOT EXISTS idx_user_storage_username ON user_storage(username);
+CREATE INDEX IF NOT EXISTS idx_storage_pins_hash ON storage_pins(content_hash);
+CREATE INDEX IF NOT EXISTS idx_storage_pins_storage ON storage_pins(storage_id);
+
+-- Add source URL columns to assets if they don't exist
+DO $$ BEGIN
+    ALTER TABLE assets ADD COLUMN source_url TEXT;
+EXCEPTION WHEN duplicate_column THEN NULL;
+END $$;
+
+DO $$ BEGIN
+    ALTER TABLE assets ADD COLUMN source_type VARCHAR(50);
+EXCEPTION WHEN duplicate_column THEN NULL;
+END $$;
 """
 
 
@@ -772,6 +812,180 @@ async def detach_renderer(username: str, l1_url: str) -> bool:
         return "DELETE 1" in result
 
 
+# ============ User Storage ============
+
+async def get_user_storage(username: str) -> list[dict]:
+    """Get all storage providers for a user."""
+    async with get_connection() as conn:
+        rows = await conn.fetch(
+            """SELECT id, username, provider_type, provider_name, config,
+                      capacity_gb, is_active, created_at, updated_at
+               FROM user_storage WHERE username = $1
+               ORDER BY created_at""",
+            username
+        )
+        return [dict(row) for row in rows]
+
+
+async def get_storage_by_id(storage_id: int) -> Optional[dict]:
+    """Get a storage provider by ID."""
+    async with get_connection() as conn:
+        row = await conn.fetchrow(
+            """SELECT id, username, provider_type, provider_name, config,
+                      capacity_gb, is_active, created_at, updated_at
+               FROM user_storage WHERE id = $1""",
+            storage_id
+        )
+        return dict(row) if row else None
+
+
+async def add_user_storage(
+    username: str,
+    provider_type: str,
+    provider_name: str,
+    config: dict,
+    capacity_gb: int
+) -> Optional[int]:
+    """Add a storage provider for a user. Returns storage ID."""
+    async with get_connection() as conn:
+        try:
+            row = await conn.fetchrow(
+                """INSERT INTO user_storage (username, provider_type, provider_name, config, capacity_gb)
+                   VALUES ($1, $2, $3, $4, $5)
+                   RETURNING id""",
+                username, provider_type, provider_name, json.dumps(config), capacity_gb
+            )
+            return row["id"] if row else None
+        except Exception:
+            return None
+
+
+async def update_user_storage(
+    storage_id: int,
+    config: Optional[dict] = None,
+    capacity_gb: Optional[int] = None,
+    is_active: Optional[bool] = None
+) -> bool:
+    """Update a storage provider."""
+    updates = []
+    params = []
+    param_num = 1
+
+    if config is not None:
+        updates.append(f"config = ${param_num}")
+        params.append(json.dumps(config))
+        param_num += 1
+    if capacity_gb is not None:
+        updates.append(f"capacity_gb = ${param_num}")
+        params.append(capacity_gb)
+        param_num += 1
+    if is_active is not None:
+        updates.append(f"is_active = ${param_num}")
+        params.append(is_active)
+        param_num += 1
+
+    if not updates:
+        return False
+
+    updates.append("updated_at = NOW()")
+    params.append(storage_id)
+
+    async with get_connection() as conn:
+        result = await conn.execute(
+            f"UPDATE user_storage SET {', '.join(updates)} WHERE id = ${param_num}",
+            *params
+        )
+        return "UPDATE 1" in result
+
+
+async def remove_user_storage(storage_id: int) -> bool:
+    """Remove a storage provider. Cascades to storage_pins."""
+    async with get_connection() as conn:
+        result = await conn.execute(
+            "DELETE FROM user_storage WHERE id = $1",
+            storage_id
+        )
+        return "DELETE 1" in result
+
+
+async def get_storage_usage(storage_id: int) -> dict:
+    """Get storage usage stats for a provider."""
+    async with get_connection() as conn:
+        row = await conn.fetchrow(
+            """SELECT
+                 COUNT(*) as pin_count,
+                 COALESCE(SUM(size_bytes), 0) as used_bytes
+               FROM storage_pins WHERE storage_id = $1""",
+            storage_id
+        )
+        return {"pin_count": row["pin_count"], "used_bytes": row["used_bytes"]}
+
+
+async def add_storage_pin(
+    content_hash: str,
+    storage_id: int,
+    ipfs_cid: Optional[str],
+    pin_type: str,
+    size_bytes: int
+) -> Optional[int]:
+    """Add a pin record. Returns pin ID."""
+    async with get_connection() as conn:
+        try:
+            row = await conn.fetchrow(
+                """INSERT INTO storage_pins (content_hash, storage_id, ipfs_cid, pin_type, size_bytes)
+                   VALUES ($1, $2, $3, $4, $5)
+                   ON CONFLICT (content_hash, storage_id) DO UPDATE SET
+                       ipfs_cid = EXCLUDED.ipfs_cid,
+                       pin_type = EXCLUDED.pin_type,
+                       size_bytes = EXCLUDED.size_bytes,
+                       pinned_at = NOW()
+                   RETURNING id""",
+                content_hash, storage_id, ipfs_cid, pin_type, size_bytes
+            )
+            return row["id"] if row else None
+        except Exception:
+            return None
+
+
+async def remove_storage_pin(content_hash: str, storage_id: int) -> bool:
+    """Remove a pin record."""
+    async with get_connection() as conn:
+        result = await conn.execute(
+            "DELETE FROM storage_pins WHERE content_hash = $1 AND storage_id = $2",
+            content_hash, storage_id
+        )
+        return "DELETE 1" in result
+
+
+async def get_pins_for_content(content_hash: str) -> list[dict]:
+    """Get all storage locations where content is pinned."""
+    async with get_connection() as conn:
+        rows = await conn.fetch(
+            """SELECT sp.*, us.provider_type, us.provider_name, us.username
+               FROM storage_pins sp
+               JOIN user_storage us ON sp.storage_id = us.id
+               WHERE sp.content_hash = $1""",
+            content_hash
+        )
+        return [dict(row) for row in rows]
+
+
+async def get_all_active_storage() -> list[dict]:
+    """Get all active storage providers (for distributed pinning)."""
+    async with get_connection() as conn:
+        rows = await conn.fetch(
+            """SELECT us.*,
+                      COALESCE(SUM(sp.size_bytes), 0) as used_bytes,
+                      COUNT(sp.id) as pin_count
+               FROM user_storage us
+               LEFT JOIN storage_pins sp ON us.id = sp.storage_id
+               WHERE us.is_active = true
+               GROUP BY us.id
+               ORDER BY us.created_at"""
+        )
+        return [dict(row) for row in rows]
+
+
 # ============ Token Revocation ============
 
 async def revoke_token(token_hash: str, username: str, expires_at) -> bool:
diff --git a/server.py b/server.py
index 4646d0d..75b6a8a 100644
--- a/server.py
+++ b/server.py
@@ -195,6 +195,27 @@ class UpdateAssetRequest(BaseModel):
     ipfs_cid: Optional[str] = None  # IPFS content identifier
 
 
+class AddStorageRequest(BaseModel):
+    """Request to add a storage provider."""
+    provider_type: str  # 'pinata', 'web3storage', 'local'
+    provider_name: Optional[str] = None  # User-friendly name
+    config: dict  # Provider-specific config (api_key, path, etc.)
+    capacity_gb: int  # Storage capacity in GB
+
+
+class UpdateStorageRequest(BaseModel):
+    """Request to update a storage provider."""
+    config: Optional[dict] = None
+    capacity_gb: Optional[int] = None
+    is_active: Optional[bool] = None
+
+
+class SetAssetSourceRequest(BaseModel):
+    """Request to set source URL for an asset."""
+    source_url: str
+    source_type: str  # 'youtube', 'local', 'url'
+
+
 # ============ Storage (Database) ============
 
 async def load_registry() -> dict:
@@ -324,6 +345,7 @@ def base_html(title: str, content: str, username: str = None) -> str:
             <a href="/users" class="text-gray-400 hover:text-white transition-colors">Users</a>
             <a href="/anchors/ui" class="text-gray-400 hover:text-white transition-colors">Anchors</a>
             <a href="/renderers" class="text-gray-400 hover:text-white transition-colors">Renderers</a>
+            <a href="/storage" class="text-gray-400 hover:text-white transition-colors">Storage</a>
             <a href="/download/client" class="text-gray-400 hover:text-white transition-colors ml-auto" title="Download CLI client">Download Client</a>
         </nav>
 
@@ -3017,6 +3039,372 @@ async def detach_renderer(request: Request):
     ''')
 
 
+# ============ User Storage ============
+
+import storage_providers
+
+
+@app.get("/storage")
+async def list_storage(request: Request, user: User = Depends(get_optional_user)):
+    """List user's storage providers. HTML for browsers, JSON for API."""
+    if not user:
+        if wants_html(request):
+            return RedirectResponse(url="/login", status_code=302)
+        raise HTTPException(401, "Authentication required")
+
+    storages = await db.get_user_storage(user.username)
+
+    # Add usage stats to each storage
+    for storage in storages:
+        usage = await db.get_storage_usage(storage["id"])
+        storage["used_bytes"] = usage["used_bytes"]
+        storage["pin_count"] = usage["pin_count"]
+        storage["donated_gb"] = storage["capacity_gb"] // 2
+        # Mask sensitive config keys for display
+        if storage.get("config"):
+            config = storage["config"] if isinstance(storage["config"], dict) else json.loads(storage["config"])
+            masked = {}
+            for k, v in config.items():
+                if "key" in k.lower() or "token" in k.lower() or "secret" in k.lower():
+                    masked[k] = v[:4] + "..." + v[-4:] if len(str(v)) > 8 else "****"
+                else:
+                    masked[k] = v
+            storage["config_display"] = masked
+
+    if wants_html(request):
+        return await ui_storage_page(user.username, storages, request)
+
+    return {"storages": storages}
+
+
+@app.post("/storage")
+async def add_storage(req: AddStorageRequest, user: User = Depends(get_required_user)):
+    """Add a storage provider."""
+    # Validate provider type
+    if req.provider_type not in ["pinata", "web3storage", "local"]:
+        raise HTTPException(400, f"Invalid provider type: {req.provider_type}")
+
+    # Test the provider connection before saving
+    provider = storage_providers.create_provider(req.provider_type, {
+        **req.config,
+        "capacity_gb": req.capacity_gb
+    })
+    if not provider:
+        raise HTTPException(400, "Failed to create provider with given config")
+
+    success, message = await provider.test_connection()
+    if not success:
+        raise HTTPException(400, f"Provider connection failed: {message}")
+
+    # Save to database
+    provider_name = req.provider_name or f"{req.provider_type}-{user.username}"
+    storage_id = await db.add_user_storage(
+        username=user.username,
+        provider_type=req.provider_type,
+        provider_name=provider_name,
+        config=req.config,
+        capacity_gb=req.capacity_gb
+    )
+
+    if not storage_id:
+        raise HTTPException(500, "Failed to save storage provider")
+
+    return {"id": storage_id, "message": f"Storage provider added: {provider_name}"}
+
+
+@app.get("/storage/{storage_id}")
+async def get_storage(storage_id: int, user: User = Depends(get_required_user)):
+    """Get a specific storage provider."""
+    storage = await db.get_storage_by_id(storage_id)
+    if not storage:
+        raise HTTPException(404, "Storage provider not found")
+    if storage["username"] != user.username:
+        raise HTTPException(403, "Not authorized")
+
+    usage = await db.get_storage_usage(storage_id)
+    storage["used_bytes"] = usage["used_bytes"]
+    storage["pin_count"] = usage["pin_count"]
+    storage["donated_gb"] = storage["capacity_gb"] // 2
+
+    return storage
+
+
+@app.patch("/storage/{storage_id}")
+async def update_storage(storage_id: int, req: UpdateStorageRequest, user: User = Depends(get_required_user)):
+    """Update a storage provider."""
+    storage = await db.get_storage_by_id(storage_id)
+    if not storage:
+        raise HTTPException(404, "Storage provider not found")
+    if storage["username"] != user.username:
+        raise HTTPException(403, "Not authorized")
+
+    # If updating config, test the new connection
+    if req.config:
+        existing_config = storage["config"] if isinstance(storage["config"], dict) else json.loads(storage["config"])
+        new_config = {**existing_config, **req.config}
+        provider = storage_providers.create_provider(storage["provider_type"], {
+            **new_config,
+            "capacity_gb": req.capacity_gb or storage["capacity_gb"]
+        })
+        if provider:
+            success, message = await provider.test_connection()
+            if not success:
+                raise HTTPException(400, f"Provider connection failed: {message}")
+
+    success = await db.update_user_storage(
+        storage_id,
+        config=req.config,
+        capacity_gb=req.capacity_gb,
+        is_active=req.is_active
+    )
+
+    if not success:
+        raise HTTPException(500, "Failed to update storage provider")
+
+    return {"message": "Storage provider updated"}
+
+
+@app.delete("/storage/{storage_id}")
+async def remove_storage(storage_id: int, user: User = Depends(get_required_user)):
+    """Remove a storage provider."""
+    storage = await db.get_storage_by_id(storage_id)
+    if not storage:
+        raise HTTPException(404, "Storage provider not found")
+    if storage["username"] != user.username:
+        raise HTTPException(403, "Not authorized")
+
+    success = await db.remove_user_storage(storage_id)
+    if not success:
+        raise HTTPException(500, "Failed to remove storage provider")
+
+    return {"message": "Storage provider removed"}
+
+
+@app.post("/storage/{storage_id}/test")
+async def test_storage(storage_id: int, request: Request, user: User = Depends(get_required_user)):
+    """Test storage provider connectivity."""
+    storage = await db.get_storage_by_id(storage_id)
+    if not storage:
+        raise HTTPException(404, "Storage provider not found")
+    if storage["username"] != user.username:
+        raise HTTPException(403, "Not authorized")
+
+    config = storage["config"] if isinstance(storage["config"], dict) else json.loads(storage["config"])
+    provider = storage_providers.create_provider(storage["provider_type"], {
+        **config,
+        "capacity_gb": storage["capacity_gb"]
+    })
+
+    if not provider:
+        if wants_html(request):
+            return HTMLResponse('<span class="text-red-400">Failed to create provider</span>')
+        raise HTTPException(500, "Failed to create provider")
+
+    success, message = await provider.test_connection()
+
+    if wants_html(request):
+        if success:
+            return HTMLResponse(f'<span class="text-green-400">{message}</span>')
+        return HTMLResponse(f'<span class="text-red-400">{message}</span>')
+
+    return {"success": success, "message": message}
+
+
+async def ui_storage_page(username: str, storages: list, request: Request) -> HTMLResponse:
+    """Render storage settings page."""
+
+    def format_bytes(b):
+        if b > 1024**3:
+            return f"{b / 1024**3:.1f} GB"
+        if b > 1024**2:
+            return f"{b / 1024**2:.1f} MB"
+        if b > 1024:
+            return f"{b / 1024:.1f} KB"
+        return f"{b} bytes"
+
+    storage_rows = ""
+    for s in storages:
+        status_class = "bg-green-600" if s["is_active"] else "bg-gray-600"
+        status_text = "Active" if s["is_active"] else "Inactive"
+        config_display = s.get("config_display", {})
+        config_html = ", ".join(f"{k}: {v}" for k, v in config_display.items() if k != "path")
+
+        storage_rows += f'''
+        <div class="p-4 bg-dark-600 rounded-lg mb-4">
+            <div class="flex justify-between items-start mb-3">
+                <div>
+                    <h3 class="font-semibold text-white">{s["provider_name"] or s["provider_type"]}</h3>
+                    <span class="text-sm text-gray-400">{s["provider_type"]}</span>
+                </div>
+                <div class="flex items-center gap-2">
+                    <span class="px-2 py-1 {status_class} text-white text-xs rounded-full">{status_text}</span>
+                    <button hx-post="/storage/{s["id"]}/test" hx-target="#test-result-{s["id"]}" hx-swap="innerHTML"
+                            class="px-2 py-1 bg-blue-600 hover:bg-blue-700 text-white text-xs rounded">Test</button>
+                    <button hx-delete="/storage/{s["id"]}" hx-confirm="Remove this storage provider?"
+                            hx-target="closest div.p-4" hx-swap="outerHTML"
+                            class="px-2 py-1 bg-red-600 hover:bg-red-700 text-white text-xs rounded">Remove</button>
+                </div>
+            </div>
+            <div class="grid grid-cols-2 md:grid-cols-4 gap-4 text-sm mb-3">
+                <div>
+                    <div class="text-gray-400">Capacity</div>
+                    <div class="text-white">{s["capacity_gb"]} GB</div>
+                </div>
+                <div>
+                    <div class="text-gray-400">Donated</div>
+                    <div class="text-white">{s["donated_gb"]} GB</div>
+                </div>
+                <div>
+                    <div class="text-gray-400">Used</div>
+                    <div class="text-white">{format_bytes(s["used_bytes"])}</div>
+                </div>
+                <div>
+                    <div class="text-gray-400">Pins</div>
+                    <div class="text-white">{s["pin_count"]}</div>
+                </div>
+            </div>
+            <div class="text-xs text-gray-500">{config_html}</div>
+            <div id="test-result-{s["id"]}" class="mt-2 text-sm"></div>
+        </div>
+        '''
+
+    if not storages:
+        storage_rows = '<p class="text-gray-400 text-center py-8">No storage providers configured.</p>'
+
+    content = f'''
+    <div class="max-w-4xl mx-auto">
+        <div class="flex justify-between items-center mb-6">
+            <h1 class="text-2xl font-bold text-white">Storage Providers</h1>
+        </div>
+
+        <div class="bg-dark-700 rounded-lg p-6 mb-6">
+            <p class="text-gray-400 mb-4">
+                Attach your own storage to help power the network. 50% of your capacity is donated to store
+                shared content, making popular assets more resilient.
+            </p>
+
+            <h2 class="text-lg font-semibold text-white mb-4">Add Storage Provider</h2>
+
+            <div class="grid grid-cols-1 md:grid-cols-3 gap-4 mb-4">
+                <button onclick="showAddForm('pinata')"
+                        class="p-4 bg-dark-600 hover:bg-dark-500 rounded-lg text-left transition-colors">
+                    <div class="font-semibold text-white">Pinata</div>
+                    <div class="text-sm text-gray-400">IPFS pinning service</div>
+                </button>
+                <button onclick="showAddForm('web3storage')"
+                        class="p-4 bg-dark-600 hover:bg-dark-500 rounded-lg text-left transition-colors">
+                    <div class="font-semibold text-white">web3.storage</div>
+                    <div class="text-sm text-gray-400">IPFS + Filecoin</div>
+                </button>
+                <button onclick="showAddForm('local')"
+                        class="p-4 bg-dark-600 hover:bg-dark-500 rounded-lg text-left transition-colors">
+                    <div class="font-semibold text-white">Local Storage</div>
+                    <div class="text-sm text-gray-400">Your own disk</div>
+                </button>
+            </div>
+
+            <div id="add-form" class="hidden bg-dark-600 rounded-lg p-4">
+                <form id="storage-form" hx-post="/storage" hx-target="#add-result" hx-swap="innerHTML">
+                    <input type="hidden" name="provider_type" id="provider_type">
+
+                    <div id="pinata-fields" class="hidden space-y-4">
+                        <div>
+                            <label class="block text-sm text-gray-400 mb-1">API Key</label>
+                            <input type="text" name="api_key" class="w-full px-3 py-2 bg-dark-700 border border-dark-500 rounded text-white">
+                        </div>
+                        <div>
+                            <label class="block text-sm text-gray-400 mb-1">Secret Key</label>
+                            <input type="password" name="secret_key" class="w-full px-3 py-2 bg-dark-700 border border-dark-500 rounded text-white">
+                        </div>
+                    </div>
+
+                    <div id="web3storage-fields" class="hidden space-y-4">
+                        <div>
+                            <label class="block text-sm text-gray-400 mb-1">API Token</label>
+                            <input type="password" name="api_token" class="w-full px-3 py-2 bg-dark-700 border border-dark-500 rounded text-white">
+                        </div>
+                    </div>
+
+                    <div id="local-fields" class="hidden space-y-4">
+                        <div>
+                            <label class="block text-sm text-gray-400 mb-1">Storage Path</label>
+                            <input type="text" name="path" placeholder="/path/to/storage" class="w-full px-3 py-2 bg-dark-700 border border-dark-500 rounded text-white">
+                        </div>
+                    </div>
+
+                    <div class="space-y-4 mt-4">
+                        <div>
+                            <label class="block text-sm text-gray-400 mb-1">Provider Name (optional)</label>
+                            <input type="text" name="provider_name" placeholder="My Storage" class="w-full px-3 py-2 bg-dark-700 border border-dark-500 rounded text-white">
+                        </div>
+                        <div>
+                            <label class="block text-sm text-gray-400 mb-1">Capacity (GB)</label>
+                            <input type="number" name="capacity_gb" value="5" min="1" class="w-full px-3 py-2 bg-dark-700 border border-dark-500 rounded text-white">
+                        </div>
+                    </div>
+
+                    <div class="flex justify-end gap-3 mt-4">
+                        <button type="button" onclick="hideAddForm()" class="px-4 py-2 bg-gray-600 hover:bg-gray-700 text-white rounded">Cancel</button>
+                        <button type="submit" class="px-4 py-2 bg-green-600 hover:bg-green-700 text-white rounded">Add Storage</button>
+                    </div>
+                </form>
+                <div id="add-result" class="mt-4"></div>
+            </div>
+        </div>
+
+        <h2 class="text-lg font-semibold text-white mb-4">Your Storage Providers</h2>
+        <div id="storage-list">
+            {storage_rows}
+        </div>
+    </div>
+
+    <script>
+    function showAddForm(type) {{
+        document.getElementById('add-form').classList.remove('hidden');
+        document.getElementById('provider_type').value = type;
+
+        // Hide all field groups
+        document.getElementById('pinata-fields').classList.add('hidden');
+        document.getElementById('web3storage-fields').classList.add('hidden');
+        document.getElementById('local-fields').classList.add('hidden');
+
+        // Show the relevant fields
+        document.getElementById(type + '-fields').classList.remove('hidden');
+    }}
+
+    function hideAddForm() {{
+        document.getElementById('add-form').classList.add('hidden');
+    }}
+
+    // Handle form submission to build proper JSON
+    document.getElementById('storage-form').addEventListener('htmx:configRequest', function(evt) {{
+        const formData = new FormData(evt.detail.elt);
+        const providerType = formData.get('provider_type');
+        const config = {{}};
+
+        if (providerType === 'pinata') {{
+            config.api_key = formData.get('api_key');
+            config.secret_key = formData.get('secret_key');
+        }} else if (providerType === 'web3storage') {{
+            config.api_token = formData.get('api_token');
+        }} else if (providerType === 'local') {{
+            config.path = formData.get('path');
+        }}
+
+        evt.detail.headers['Content-Type'] = 'application/json';
+        evt.detail.parameters = JSON.stringify({{
+            provider_type: providerType,
+            provider_name: formData.get('provider_name') || null,
+            config: config,
+            capacity_gb: parseInt(formData.get('capacity_gb'))
+        }});
+    }});
+    </script>
+    '''
+
+    return HTMLResponse(base_html("Storage", content, username))
+
+
 # ============ Client Download ============
 
 CLIENT_TARBALL = Path(__file__).parent / "artdag-client.tar.gz"
diff --git a/storage_providers.py b/storage_providers.py
new file mode 100644
index 0000000..2088afe
--- /dev/null
+++ b/storage_providers.py
@@ -0,0 +1,511 @@
+"""
+Storage provider abstraction for user-attachable storage.
+
+Supports:
+- Pinata (IPFS pinning service)
+- web3.storage (IPFS pinning service)
+- Local filesystem storage
+"""
+
+import hashlib
+import json
+import logging
+import os
+import shutil
+from abc import ABC, abstractmethod
+from pathlib import Path
+from typing import Optional
+
+import requests
+
+logger = logging.getLogger(__name__)
+
+
+class StorageProvider(ABC):
+    """Abstract base class for storage backends."""
+
+    provider_type: str = "unknown"
+
+    @abstractmethod
+    async def pin(self, content_hash: str, data: bytes, filename: Optional[str] = None) -> Optional[str]:
+        """
+        Pin content to storage.
+
+        Args:
+            content_hash: SHA3-256 hash of the content
+            data: Raw bytes to store
+            filename: Optional filename hint
+
+        Returns:
+            IPFS CID or provider-specific ID, or None on failure
+        """
+        pass
+
+    @abstractmethod
+    async def unpin(self, content_hash: str) -> bool:
+        """
+        Unpin content from storage.
+
+        Args:
+            content_hash: SHA3-256 hash of the content
+
+        Returns:
+            True if unpinned successfully
+        """
+        pass
+
+    @abstractmethod
+    async def get(self, content_hash: str) -> Optional[bytes]:
+        """
+        Retrieve content from storage.
+
+        Args:
+            content_hash: SHA3-256 hash of the content
+
+        Returns:
+            Raw bytes or None if not found
+        """
+        pass
+
+    @abstractmethod
+    async def is_pinned(self, content_hash: str) -> bool:
+        """Check if content is pinned in this storage."""
+        pass
+
+    @abstractmethod
+    async def test_connection(self) -> tuple[bool, str]:
+        """
+        Test connectivity to the storage provider.
+
+        Returns:
+            (success, message) tuple
+        """
+        pass
+
+    @abstractmethod
+    def get_usage(self) -> dict:
+        """
+        Get storage usage statistics.
+
+        Returns:
+            {used_bytes, capacity_bytes, pin_count}
+        """
+        pass
+
+
+class PinataProvider(StorageProvider):
+    """Pinata IPFS pinning service provider."""
+
+    provider_type = "pinata"
+
+    def __init__(self, api_key: str, secret_key: str, capacity_gb: int = 1):
+        self.api_key = api_key
+        self.secret_key = secret_key
+        self.capacity_bytes = capacity_gb * 1024**3
+        self.base_url = "https://api.pinata.cloud"
+        self._usage_cache = None
+
+    def _headers(self) -> dict:
+        return {
+            "pinata_api_key": self.api_key,
+            "pinata_secret_api_key": self.secret_key,
+        }
+
+    async def pin(self, content_hash: str, data: bytes, filename: Optional[str] = None) -> Optional[str]:
+        """Pin content to Pinata."""
+        try:
+            import asyncio
+
+            def do_pin():
+                files = {"file": (filename or f"{content_hash[:16]}.bin", data)}
+                metadata = {
+                    "name": filename or content_hash[:16],
+                    "keyvalues": {"content_hash": content_hash}
+                }
+                response = requests.post(
+                    f"{self.base_url}/pinning/pinFileToIPFS",
+                    files=files,
+                    data={"pinataMetadata": json.dumps(metadata)},
+                    headers=self._headers(),
+                    timeout=120
+                )
+                response.raise_for_status()
+                return response.json().get("IpfsHash")
+
+            cid = await asyncio.to_thread(do_pin)
+            logger.info(f"Pinata: Pinned {content_hash[:16]}... as {cid}")
+            return cid
+        except Exception as e:
+            logger.error(f"Pinata pin failed: {e}")
+            return None
+
+    async def unpin(self, content_hash: str) -> bool:
+        """Unpin content from Pinata by finding its CID first."""
+        try:
+            import asyncio
+
+            def do_unpin():
+                # First find the pin by content_hash metadata
+                response = requests.get(
+                    f"{self.base_url}/data/pinList",
+                    params={"metadata[keyvalues][content_hash]": content_hash, "status": "pinned"},
+                    headers=self._headers(),
+                    timeout=30
+                )
+                response.raise_for_status()
+                pins = response.json().get("rows", [])
+
+                if not pins:
+                    return False
+
+                # Unpin each matching CID
+                for pin in pins:
+                    cid = pin.get("ipfs_pin_hash")
+                    if cid:
+                        resp = requests.delete(
+                            f"{self.base_url}/pinning/unpin/{cid}",
+                            headers=self._headers(),
+                            timeout=30
+                        )
+                        resp.raise_for_status()
+                return True
+
+            result = await asyncio.to_thread(do_unpin)
+            logger.info(f"Pinata: Unpinned {content_hash[:16]}...")
+            return result
+        except Exception as e:
+            logger.error(f"Pinata unpin failed: {e}")
+            return False
+
+    async def get(self, content_hash: str) -> Optional[bytes]:
+        """Get content from Pinata via IPFS gateway."""
+        try:
+            import asyncio
+
+            def do_get():
+                # First find the CID
+                response = requests.get(
+                    f"{self.base_url}/data/pinList",
+                    params={"metadata[keyvalues][content_hash]": content_hash, "status": "pinned"},
+                    headers=self._headers(),
+                    timeout=30
+                )
+                response.raise_for_status()
+                pins = response.json().get("rows", [])
+
+                if not pins:
+                    return None
+
+                cid = pins[0].get("ipfs_pin_hash")
+                if not cid:
+                    return None
+
+                # Fetch from gateway
+                gateway_response = requests.get(
+                    f"https://gateway.pinata.cloud/ipfs/{cid}",
+                    timeout=120
+                )
+                gateway_response.raise_for_status()
+                return gateway_response.content
+
+            return await asyncio.to_thread(do_get)
+        except Exception as e:
+            logger.error(f"Pinata get failed: {e}")
+            return None
+
+    async def is_pinned(self, content_hash: str) -> bool:
+        """Check if content is pinned on Pinata."""
+        try:
+            import asyncio
+
+            def do_check():
+                response = requests.get(
+                    f"{self.base_url}/data/pinList",
+                    params={"metadata[keyvalues][content_hash]": content_hash, "status": "pinned"},
+                    headers=self._headers(),
+                    timeout=30
+                )
+                response.raise_for_status()
+                return len(response.json().get("rows", [])) > 0
+
+            return await asyncio.to_thread(do_check)
+        except Exception:
+            return False
+
+    async def test_connection(self) -> tuple[bool, str]:
+        """Test Pinata API connectivity."""
+        try:
+            import asyncio
+
+            def do_test():
+                response = requests.get(
+                    f"{self.base_url}/data/testAuthentication",
+                    headers=self._headers(),
+                    timeout=10
+                )
+                response.raise_for_status()
+                return True, "Connected to Pinata successfully"
+
+            return await asyncio.to_thread(do_test)
+        except requests.exceptions.HTTPError as e:
+            if e.response.status_code == 401:
+                return False, "Invalid API credentials"
+            return False, f"HTTP error: {e}"
+        except Exception as e:
+            return False, f"Connection failed: {e}"
+
+    def get_usage(self) -> dict:
+        """Get Pinata usage stats."""
+        try:
+            response = requests.get(
+                f"{self.base_url}/data/userPinnedDataTotal",
+                headers=self._headers(),
+                timeout=10
+            )
+            response.raise_for_status()
+            data = response.json()
+            return {
+                "used_bytes": data.get("pin_size_total", 0),
+                "capacity_bytes": self.capacity_bytes,
+                "pin_count": data.get("pin_count", 0)
+            }
+        except Exception:
+            return {"used_bytes": 0, "capacity_bytes": self.capacity_bytes, "pin_count": 0}
+
+
+class Web3StorageProvider(StorageProvider):
+    """web3.storage pinning service provider."""
+
+    provider_type = "web3storage"
+
+    def __init__(self, api_token: str, capacity_gb: int = 1):
+        self.api_token = api_token
+        self.capacity_bytes = capacity_gb * 1024**3
+        self.base_url = "https://api.web3.storage"
+
+    def _headers(self) -> dict:
+        return {"Authorization": f"Bearer {self.api_token}"}
+
+    async def pin(self, content_hash: str, data: bytes, filename: Optional[str] = None) -> Optional[str]:
+        """Pin content to web3.storage."""
+        try:
+            import asyncio
+
+            def do_pin():
+                response = requests.post(
+                    f"{self.base_url}/upload",
+                    data=data,
+                    headers={
+                        **self._headers(),
+                        "X-Name": filename or content_hash[:16]
+                    },
+                    timeout=120
+                )
+                response.raise_for_status()
+                return response.json().get("cid")
+
+            cid = await asyncio.to_thread(do_pin)
+            logger.info(f"web3.storage: Pinned {content_hash[:16]}... as {cid}")
+            return cid
+        except Exception as e:
+            logger.error(f"web3.storage pin failed: {e}")
+            return None
+
+    async def unpin(self, content_hash: str) -> bool:
+        """web3.storage doesn't support unpinning - data is stored permanently."""
+        logger.warning("web3.storage: Unpinning not supported (permanent storage)")
+        return False
+
+    async def get(self, content_hash: str) -> Optional[bytes]:
+        """Get content from web3.storage - would need CID mapping."""
+        # web3.storage requires knowing the CID to fetch
+        # For now, return None - we'd need to maintain a mapping
+        return None
+
+    async def is_pinned(self, content_hash: str) -> bool:
+        """Check if content is pinned - would need CID mapping."""
+        return False
+
+    async def test_connection(self) -> tuple[bool, str]:
+        """Test web3.storage API connectivity."""
+        try:
+            import asyncio
+
+            def do_test():
+                response = requests.get(
+                    f"{self.base_url}/user/uploads",
+                    headers=self._headers(),
+                    params={"size": 1},
+                    timeout=10
+                )
+                response.raise_for_status()
+                return True, "Connected to web3.storage successfully"
+
+            return await asyncio.to_thread(do_test)
+        except requests.exceptions.HTTPError as e:
+            if e.response.status_code == 401:
+                return False, "Invalid API token"
+            return False, f"HTTP error: {e}"
+        except Exception as e:
+            return False, f"Connection failed: {e}"
+
+    def get_usage(self) -> dict:
+        """Get web3.storage usage stats."""
+        try:
+            response = requests.get(
+                f"{self.base_url}/user/uploads",
+                headers=self._headers(),
+                params={"size": 1000},
+                timeout=30
+            )
+            response.raise_for_status()
+            uploads = response.json()
+            total_size = sum(u.get("dagSize", 0) for u in uploads)
+            return {
+                "used_bytes": total_size,
+                "capacity_bytes": self.capacity_bytes,
+                "pin_count": len(uploads)
+            }
+        except Exception:
+            return {"used_bytes": 0, "capacity_bytes": self.capacity_bytes, "pin_count": 0}
+
+
+class LocalStorageProvider(StorageProvider):
+    """Local filesystem storage provider."""
+
+    provider_type = "local"
+
+    def __init__(self, base_path: str, capacity_gb: int = 10):
+        self.base_path = Path(base_path)
+        self.capacity_bytes = capacity_gb * 1024**3
+        # Create directory if it doesn't exist
+        self.base_path.mkdir(parents=True, exist_ok=True)
+
+    def _get_file_path(self, content_hash: str) -> Path:
+        """Get file path for a content hash (using subdirectories)."""
+        # Use first 2 chars as subdirectory for better filesystem performance
+        subdir = content_hash[:2]
+        return self.base_path / subdir / content_hash
+
+    async def pin(self, content_hash: str, data: bytes, filename: Optional[str] = None) -> Optional[str]:
+        """Store content locally."""
+        try:
+            import asyncio
+
+            def do_store():
+                file_path = self._get_file_path(content_hash)
+                file_path.parent.mkdir(parents=True, exist_ok=True)
+                file_path.write_bytes(data)
+                return content_hash  # Use content_hash as ID for local storage
+
+            result = await asyncio.to_thread(do_store)
+            logger.info(f"Local: Stored {content_hash[:16]}...")
+            return result
+        except Exception as e:
+            logger.error(f"Local storage failed: {e}")
+            return None
+
+    async def unpin(self, content_hash: str) -> bool:
+        """Remove content from local storage."""
+        try:
+            import asyncio
+
+            def do_remove():
+                file_path = self._get_file_path(content_hash)
+                if file_path.exists():
+                    file_path.unlink()
+                    return True
+                return False
+
+            return await asyncio.to_thread(do_remove)
+        except Exception as e:
+            logger.error(f"Local unpin failed: {e}")
+            return False
+
+    async def get(self, content_hash: str) -> Optional[bytes]:
+        """Get content from local storage."""
+        try:
+            import asyncio
+
+            def do_get():
+                file_path = self._get_file_path(content_hash)
+                if file_path.exists():
+                    return file_path.read_bytes()
+                return None
+
+            return await asyncio.to_thread(do_get)
+        except Exception as e:
+            logger.error(f"Local get failed: {e}")
+            return None
+
+    async def is_pinned(self, content_hash: str) -> bool:
+        """Check if content exists in local storage."""
+        return self._get_file_path(content_hash).exists()
+
+    async def test_connection(self) -> tuple[bool, str]:
+        """Test local storage is writable."""
+        try:
+            test_file = self.base_path / ".write_test"
+            test_file.write_text("test")
+            test_file.unlink()
+            return True, f"Local storage ready at {self.base_path}"
+        except Exception as e:
+            return False, f"Cannot write to {self.base_path}: {e}"
+
+    def get_usage(self) -> dict:
+        """Get local storage usage stats."""
+        try:
+            total_size = 0
+            file_count = 0
+            for subdir in self.base_path.iterdir():
+                if subdir.is_dir() and len(subdir.name) == 2:
+                    for f in subdir.iterdir():
+                        if f.is_file():
+                            total_size += f.stat().st_size
+                            file_count += 1
+            return {
+                "used_bytes": total_size,
+                "capacity_bytes": self.capacity_bytes,
+                "pin_count": file_count
+            }
+        except Exception:
+            return {"used_bytes": 0, "capacity_bytes": self.capacity_bytes, "pin_count": 0}
+
+
+def create_provider(provider_type: str, config: dict) -> Optional[StorageProvider]:
+    """
+    Factory function to create a storage provider from config.
+
+    Args:
+        provider_type: 'pinata', 'web3storage', or 'local'
+        config: Provider-specific configuration dict
+
+    Returns:
+        StorageProvider instance or None if invalid
+    """
+    try:
+        if provider_type == "pinata":
+            return PinataProvider(
+                api_key=config["api_key"],
+                secret_key=config["secret_key"],
+                capacity_gb=config.get("capacity_gb", 1)
+            )
+        elif provider_type == "web3storage":
+            return Web3StorageProvider(
+                api_token=config["api_token"],
+                capacity_gb=config.get("capacity_gb", 1)
+            )
+        elif provider_type == "local":
+            return LocalStorageProvider(
+                base_path=config["path"],
+                capacity_gb=config.get("capacity_gb", 10)
+            )
+        else:
+            logger.error(f"Unknown provider type: {provider_type}")
+            return None
+    except KeyError as e:
+        logger.error(f"Missing config key for {provider_type}: {e}")
+        return None
+    except Exception as e:
+        logger.error(f"Failed to create provider {provider_type}: {e}")
+        return None