| # KB: Domain Router | |
| The **Domain Router** is the traffic controller of the EbookBuilder ecosystem, responsible for directing requests to the correct agent or service based on the context of the task. | |
| ## Functions | |
| - **Contextual Routing**: Analyzes incoming user prompts to determine if they need a "Creative Writer", an "API Wizard", or a "Technical Editor". | |
| - **Multi-Tenant Support**: Maps custom subdomains (e.g., `user-1.ebookbuilder.com`) to specific Hugging Face Space instances. | |
| - **Load Balancing**: Distributes heavy generation tasks across multiple backend model endpoints to maintain responsiveness. | |
| ## Architecture | |
| - **Layer 7 Routing**: Operates at the application level to inspect headers and path parameters. | |
| - **Failover Logic**: If a specific model provider is down, the router automatically switches to a fallback (e.g., switching from Vertex AI to Hugging Face Inference Endpoints). | |