> For the complete documentation index, see [llms.txt](https://developer.tokeninc.com/token-developer-portal-1/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.tokeninc.com/token-developer-portal-1/payment-service/architecture.md). # Architecture The architecture defines a layered platform structure for the TokenOS system.\ At the base lies the **OS**, providing the fundamental operating environment. Above it, the **TokenOS Platform** is organized into three main service domains: * **System** (Device Services, KMS Service, RKL Service), * **Fiscal** (Fiscal Service), * **Payment** (Card Service for EMV). On top of the platform, the **App Layer** hosts applications such as the **Token Launcher**, **ATMS**, **ECR/Sale App**, **Payment Gateway**, and **Payment Native Apps**, interacting with the underlying services. Externally, through secure network connections, the platform integrates with higher-level systems: * **Token POS Services** (e.g., ATMS, RKL), * **Token X Services** (e.g., Connect, Store, Fiscal Cloud, Maestro), * **Payment Services**. These services are orchestrated and managed centrally by the **Token TSM** (Trusted Service Manager), enabling secure management and communication between the device-side platform and external ecosystems.