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docs/architecture/react-frontend/layers/infrastructure.md

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+# Infrastructure Layer
+
+App-wide technical adapters connecting the app to technical systems and shared runtime services: HTTP clients and interceptors, shared React Query helpers (keys, response types, error normalization), storage/browser adapters, formatting service adapters, technical config wrappers. No feature business logic.
+
+```plaintext
+infrastructure/
+├── axios/
+│   ├── index.ts              # configured axios client
+│   ├── interceptors.ts       # request/response interceptors
+│   └── axios.d.ts            # axios type augmentation
+│
+├── reactQuery/
+│   ├── index.ts
+│   ├── errors.ts             # query error handling helpers
+│   ├── helpers.ts            # query key and pagination helpers
+│   ├── queryParams.ts        # table/query-param mapping helpers
+│   └── types.ts              # shared API response/query types
+│
+├── IntlDate.ts               # date formatting service adapter
+└── IntlName.ts               # name formatting service adapter
+```
+
+## Rules
+
+1. Feature-agnostic: no module business rules, no page/component composition, no entity mapping that belongs in a module `data/mapper`.
+2. API modules use infrastructure clients (`import { axiosClient } from "#infrastructure/axios"`) instead of creating their own.
+3. React Query helpers shared across modules (key builders, list response types, pagination, error extraction) live here.
+4. UI never calls raw HTTP clients — view/page code uses data-layer hooks; direct `#infrastructure/axios` usage belongs in API/data modules.
+5. Generic formatting adapters (`IntlDate`, `IntlName`) may be consumed by UI.
+6. Keep app-state coupling narrow — prefer dependency injection; don't import feature modules into infrastructure.
+
+## Examples
+
+```ts
+import { axiosClient } from "#infrastructure/axios";
+
+export class UserAPI {
+  getDetailed(id: number) {
+    return axiosClient.get(`/users/${id}`).then((response) => response.data);
+  }
+}
+```
+
+```ts
+import {
+  createKeyBuilder,
+  getPaginationInfo,
+} from "#infrastructure/reactQuery";
+
+export const usersCacheKey = createKeyBuilder("USERS", "LIST");
+```