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docs/features/checked/router/router-yaml-json-configuration-with-hot-reload.md

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+# Router YAML/JSON Configuration with Hot-Reload
+
+## Module
+Router
+
+## Status
+IMPLEMENTED
+
+## Description
+Centralized router configuration supporting YAML and JSON formats with `IOptionsMonitor` integration and `FileSystemWatcher`-based hot-reload. Includes validation, change event notification, and per-service routing options.
+
+## Implementation Details
+- **Modules**: `src/Router/__Libraries/StellaOps.Router.Config/`
+- **Key Classes**:
+  - `RouterConfig` (`src/Router/__Libraries/StellaOps.Router.Config/RouterConfig.cs`) - root configuration model for router settings
+  - `RouterConfigProvider` (`src/Router/__Libraries/StellaOps.Router.Config/RouterConfigProvider.cs`) - watches config files and provides hot-reload via `IOptionsMonitor`
+  - `RouterConfigOptions` (`src/Router/__Libraries/StellaOps.Router.Config/RouterConfigOptions.cs`) - options for config file paths and reload behavior
+  - `GatewayOptions` (`src/Router/StellaOps.Gateway.WebService/Configuration/GatewayOptions.cs`) - gateway-specific configuration options
+  - `GatewayOptionsValidator` (`src/Router/StellaOps.Gateway.WebService/Configuration/GatewayOptionsValidator.cs`) - validates gateway configuration
+- **Interfaces**: `IRouterConfigProvider`
+- **Source**: batch_52/file_07.md
+
+## E2E Test Plan
+- [ ] Load router configuration from a YAML file and verify `RouterConfig` is populated correctly
+- [ ] Load configuration from a JSON file and verify equivalent behavior
+- [ ] Modify the config file at runtime and verify `RouterConfigProvider` triggers hot-reload
+- [ ] Verify change event notification: subscribe to config changes and confirm notification on reload
+- [ ] Verify validation: provide invalid config values and confirm `GatewayOptionsValidator` rejects them