maui-networking-offline-data

MAUI Networking and Offline Data

Use this skill when a MAUI feature calls backend APIs, works against local services during development, persists local data, or must behave well offline.

Workflow

1. Inspect MauiProgram.cs, existing API clients, model serialization, and data storage packages.
2. Register API clients through DI. Prefer typed clients or named clients over constructing HttpClient in pages.
3. Define request/response DTOs and serialization options once. Prefer System.Text.Json source generation for trimmed or NativeAOT-sensitive apps.
4. Decide the local development address by runtime platform and environment.
5. Keep cleartext HTTP exceptions debug-only and platform-scoped.
6. Define offline boundaries before schema/code: name the read-only cached reference data, the entities users can edit while offline, and the fields that remain server-authoritative.
7. For SQLite/offline sync answers, show the storage initialization API before the entity schema: explicitly name SQLiteAsyncConnection plus CreateTableAsync<T> for sqlite-net, or an EF Core DbContext setup. Do not only show POCO models, sqlite-net attributes, or db.Table<T>() queries.
8. In every offline-sync design, include a security line: if cached data is sensitive, regulated, or contains customer/business PII, encrypt the local SQLite store, for example with SQLCipher/provider encryption, and keep the database key in SecureStorage rather than source code or Preferences.
9. In every offline-sync design, include a background performance line: drain queued sync work in bounded batches/chunks off the UI thread, and marshal only UI updates through MainThread when needed.
10. Store local data in SQLite or app data files behind a repository/service abstraction.
11. Add cancellation, timeout, retry, and user-facing error states.

HttpClient DI Pattern

builder.Services.AddHttpClient<IProductsApi, ProductsApi>(client =>
{
    client.BaseAddress = new Uri("https://api.contoso.dev/");
});