diff --git a/src/core/config_loader.py b/src/core/config_loader.py
index 0404021c7..9ca2a56bb 100644
--- a/src/core/config_loader.py
+++ b/src/core/config_loader.py
@@ -153,6 +153,32 @@ def get_tenant_by_subdomain(subdomain: str) -> dict[str, Any] | None:
         raise
 
 
+def get_tenant_by_id(tenant_id: str) -> dict[str, Any] | None:
+    """Get tenant by tenant_id.
+
+    Args:
+        tenant_id: The tenant_id to look up (e.g., 'tenant_wonderstruck')
+
+    Returns:
+        Tenant dict if found, None otherwise
+    """
+    try:
+        with get_db_session() as db_session:
+            stmt = select(Tenant).filter_by(tenant_id=tenant_id, is_active=True)
+            tenant = db_session.scalars(stmt).first()
+
+            if tenant:
+                from src.core.utils.tenant_utils import serialize_tenant_to_dict
+
+                return serialize_tenant_to_dict(tenant)
+            return None
+    except Exception as e:
+        # If table doesn't exist or other DB errors, return None
+        if "no such table" in str(e) or "does not exist" in str(e):
+            return None
+        raise
+
+
 def get_tenant_by_virtual_host(virtual_host: str) -> dict[str, Any] | None:
     """Get tenant by virtual host."""
     try:
diff --git a/src/core/main.py b/src/core/main.py
index fabaa82ef..2501f65e2 100644
--- a/src/core/main.py
+++ b/src/core/main.py
@@ -37,6 +37,7 @@
 # Other imports
 from src.core.config_loader import (
     get_current_tenant,
+    get_tenant_by_id,
     get_tenant_by_subdomain,
     get_tenant_by_virtual_host,
     load_config,
@@ -405,7 +406,13 @@ def get_principal_from_context(context: Context | None) -> str | None:
                 # Fallback: assume it's already a tenant_id
                 requested_tenant_id = tenant_hint
                 detection_method = "x-adcp-tenant header (direct)"
-                console.print(f"[yellow]Using x-adcp-tenant as tenant_id directly: {requested_tenant_id}[/yellow]")
+                # Need to look up and set tenant context
+                tenant_context = get_tenant_by_id(tenant_hint)
+                if tenant_context:
+                    set_current_tenant(tenant_context)
+                    console.print(f"[green]Tenant context set for tenant_id: {requested_tenant_id}[/green]")
+                else:
+                    console.print(f"[yellow]Using x-adcp-tenant as tenant_id directly: {requested_tenant_id}[/yellow]")
 
     # 3. Check Apx-Incoming-Host header (for Approximated.app virtual hosts)
     if not requested_tenant_id:
diff --git a/test_webhook_url.py b/test_webhook_url.py
deleted file mode 100644
index 726ba5f7d..000000000
--- a/test_webhook_url.py
+++ /dev/null
@@ -1,62 +0,0 @@
-#!/usr/bin/env python3
-"""Test that sync_creatives accepts webhook_url parameter."""
-
-import asyncio
-import sys
-from datetime import UTC, datetime
-
-from fastmcp.client import Client
-from fastmcp.client.transports import StreamableHttpTransport
-
-
-async def test_sync_creatives_with_webhook():
-    """Test sync_creatives with webhook_url parameter."""
-
-    # Use local MCP server
-    headers = {
-        "x-adcp-auth": "f68ZhutgGiHEMwHo8jKlr0heEsptkmElRVNfzYiz1IY",  # Default tenant token
-    }
-
-    transport = StreamableHttpTransport(url="http://localhost:8085/mcp/", headers=headers)
-
-    async with Client(transport=transport) as client:
-        print("✓ Connected to MCP server")
-
-        # Create a test creative
-        test_creative = {
-            "creative_id": f"test_webhook_{datetime.now(UTC).timestamp()}",
-            "name": "Test Creative with Webhook",
-            "format_id": "display_300x250",
-            "url": "https://example.com/test-ad.jpg",
-            "click_url": "https://example.com/click",
-            "width": 300,
-            "height": 250,
-        }
-
-        print("\n📤 Calling sync_creatives with webhook_url parameter...")
-        print(f"   Creative: {test_creative['name']}")
-        print("   Webhook: https://webhook.example.com/notify")
-
-        try:
-            result = await client.call_tool(
-                "sync_creatives", {"creatives": [test_creative], "webhook_url": "https://webhook.example.com/notify"}
-            )
-
-            print("\n✅ SUCCESS! Server accepted webhook_url parameter")
-            print("\n📊 Result:")
-            print(f"   {result}")
-
-            return True
-
-        except Exception as e:
-            print(f"\n❌ FAILED: {e}")
-            if "webhook_url" in str(e) and "Unexpected keyword argument" in str(e):
-                print("\n🔍 Diagnosis: Server doesn't accept webhook_url parameter yet")
-                print("   - Check if server was restarted after code changes")
-                print("   - Verify _sync_creatives_impl() has webhook_url parameter")
-            return False
-
-
-if __name__ == "__main__":
-    success = asyncio.run(test_sync_creatives_with_webhook())
-    sys.exit(0 if success else 1)