docs: add AGENTS.md

AGENTS.md

@@ -0,0 +1,125 @@
+# AGENTS.md
+
+LocalSend disallows AI generated contributions unless:
+
+- they are bug fixes or
+- very small or
+- you prove your expertise in your field
+
+This file provides guidance to LLMs when working with code in this repository.
+
+## Repository layout
+
+This is a multi-language monorepo: a Flutter app on top of a Rust protocol implementation.
+
+| Path                           | What it is                                                                                                                                                  |
+|--------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `app/`                         | The Flutter app (`localsend_app`). UI, providers, persistence, platform channels.                                                                           |
+| `packages/localsend_isolates/` | Dart isolate layer + `flutter_rust_bridge` (FRB) bindings. Owns `rust/` (the Flutter plugin crate `rust_lib_localsend_app`) and `rust_builder/` (cargokit). |
+| `packages/core/`               | Rust crate `localsend`: protocol, HTTP server/client, crypto, WebRTC. No Flutter dependency.                                                                |
+| `packages/typed_isolates/`     | Small standalone package wrapping Dart `Isolate` with typed send/receive channels.                                                                          |
+| `server/`                      | Axum WebSocket signaling server for WebRTC (`/v1/ws`). Deployed separately, see `server/Dockerfile`.                                                        |
+| `cli/`                         | Rust CLI crate — currently a stub.                                                                                                                          |
+| `support/scripts/`             | Release/packaging scripts (per-platform builds, MSIX, Inno Setup, FOSS stripping).                                                                          |
+
+There is no Cargo workspace; `packages/core`, `packages/localsend_isolates/rust`, `server`, and `cli` are independent crates.
+
+Dependency direction: `app` → `localsend_isolates` → (`typed_isolates`, `rust_lib_localsend_app` → `localsend` core).
+The app depends on **only** `localsend_isolates` — not on `flutter_rust_bridge`, `typed_isolates`, or the plugin crate directly.
+
+## Flutter version
+
+Pinned to the version in `.fvmrc` (also mirrored in `.github/workflows/ci.yml` and `app/pubspec.yaml`, plus the `support/submodules/flutter` git submodule). Use **`fvm flutter` / `fvm dart`** instead of the system-wide toolchain.
+Bumping the version means updating all four places — see the "Bump Flutter" section of `CONTRIBUTING.md`.
+
+## Commands
+
+Run from `app/` unless stated otherwise.
+
+```bash
+fvm flutter pub get
+fvm dart run build_runner build  # dart_mappable, freezed, flutter_gen, mockito
+fvm dart run slang               # i18n codegen (slang_build_runner is disabled in build.yaml)
+fvm flutter run
+```
+
+Checks (what CI runs):
+
+```bash
+fvm dart format --set-exit-if-changed lib test   # CI deletes lib/gen first; generated code is not format-checked
+fvm flutter analyze
+fvm flutter test
+fvm flutter test test/unit/util/security_helper_test.dart          # single file
+fvm flutter test --plain-name 'some test name'                     # single test
+```
+
+Formatting is **150 columns** (`page_width: 150` in `analysis_options.yaml`, `trailing_commas: preserve`). Any tool that reformats generated Dart at 80 columns creates pure noise — reformat with `fvm dart format` afterwards.
+
+Rust:
+
+```bash
+cargo test --features full       # in packages/core — see "Core crate features" below
+cargo clippy --features full
+cargo check                      # in packages/localsend_isolates/rust, server, cli
+```
+
+FRB codegen — run from `packages/localsend_isolates/`:
+
+```bash
+flutter_rust_bridge_codegen generate    # config in flutter_rust_bridge.yaml (dart_format_line_length: 150)
+```
+
+Codegen has a habit of rewriting `app/test/mocks.mocks.dart` at 80 columns; revert that file if it shows up in the diff.
+
+`packages/localsend_isolates` has its own `build.yaml`/`pubspec.yaml` and needs its own `pub get` + `build_runner` run when its models change. CI additionally runs `flutter pub get` in `packages/localsend_isolates/rust_builder/cargokit/build_tool`.
+
+## Core crate features
+
+`packages/core` gates almost everything behind Cargo features (`crypto`, `http`, `webrtc`, `webrtc-signaling`, `full`), and `default = []`. **Always build and test it with `--features full`.** A bare `cargo check`/`cargo build` fails because modules are declared unconditionally while their dependencies are optional — that is pre-existing and expected, not a regression.
+
+## Architecture
+
+### State management
+
+Refena (`refena_flutter`), not Riverpod. Providers live in `app/lib/provider/`; `NotifierProvider` for plain state, `ReduxProvider` + dispatched action classes for anything the isolate layer touches. `app/lib/config/init.dart` (`preInit`) is the bootstrap: it initialises logging, `RustLib.init()`, persistence, the isolate container, tray/window, and returns the `RefenaContainer` that `main.dart` mounts.
+
+Models are `dart_mappable` (`@MappableClass`, `.mapper.dart` parts) with renamed methods — `fromJson`/`toJson` are the **Map** converters and `deserialize`/`serialize` are the string ones (configured in both `build.yaml` files). Freezed is used for FRB-adjacent unions.
+
+### Isolates
+
+The heavy networking never runs on the main isolate. `packages/localsend_isolates/lib/src/isolate/`:
+
+- `parent/parent_isolate_provider.dart` — `ParentIsolateState` holds one `IsolateConnector` per child (http scan discovery, multicast discovery, http upload, http server) plus a `SyncState` mirrored into every child. `IsolateSetupAction` spawns them.
+- `parent/actions.dart`, `parent/actions_sync.dart` — the only supported way for the app to talk to the children.
+- `child/*_isolate.dart` — child entry points; they translate typed task messages into calls on `lib/src/task/`.
+- `lib/src/task/` — pure helpers only; **isolate logic is prohibited there** (see its `README.md`).
+
+State that children need (alias, port, protocol, whether the server runs, whether web send is on) is pushed via `IsolateSyncServerStateAction`. Children read `syncState` at start, so sync **before** starting the server.
+
+### Networking (Rust)
+
+The HTTP server and client are Rust, not Dart. `packages/core/src/http/server/` implements protocol v2 (v1 endpoints are not served) plus the "web send" download flow (`server/web.rs`) and an internal `show` endpoint used to foreground an already-running instance.
+
+Integration is channel-based: `start_with_port` takes a `ServerConfigV2 { pin, event_tx, web_send }` and emits `ServerEventV2` events (`Register`, `PrepareUpload` with a `decision_tx` oneshot, `FileUpload` with a byte stream + `result_tx`, `PrepareDownload`, `SessionEnd`, `PrepareUploadAborted`, `CancelReceived`). Only **one upload session is active at a time**; cancellation safety comes from drop guards (`PendingSessionGuard`, `UploadGuard`, `PendingWebSessionGuard`). There is deliberately no `auto_accept` in core — the app auto-accepts by answering `decision_tx` immediately. New server→app interactions should extend `ServerEventV2` rather than adding side channels.
+
+The FRB layer (`packages/localsend_isolates/rust/src/api/server.rs`) exposes `start_server` + an opaque `RsHttpServer` whose `listen` merges the v2, web-send and internal channels into one `RsServerEvent` stream; responder oneshots stay on the Rust side. On the Dart side `child/server_isolate.dart` turns those into `HttpServerEvent`s, which `app/lib/provider/network/server/server_provider.dart` routes to `ReceiveController` / `SendController` — these are **event handlers, not route handlers**.
+
+Save targets are decided in Dart (`prepareFileSaveTarget`) and written by Rust: a path, or an Android SAF file descriptor obtained through the `org.localsend.localsend_app/localsend` method channel. Gallery saves go through a cache file first.
+
+TLS uses per-device on-the-fly certificates with **mandatory client certificates**; the peer identity is the uppercase-hex SHA-256 of the client cert DER, and `Register` is simply not emitted when a payload's claimed fingerprint disagrees with the cert. Prefer `event.certFingerprint ?? event.info.fingerprint` — the payload fallback only exists for encryption-off mode.
+
+Both the receive pin and the web-send pin are fixed at server start, so changing either restarts the server.
+
+Web assets for the browser download page are embedded from `packages/core/assets/web/`.
+
+### i18n
+
+Slang, source files in `app/assets/i18n/` (`<locale>.json` plus `_missing_translations_<locale>.json`), generated output in `app/lib/gen/`. Translations are managed on Weblate; fields prefixed with `@` are metadata for translators and are not used by the app. `app/test/unit/i18n_test.dart` guards the locale set.
+
+### FOSS build
+
+`in_app_purchase` and the donation UI are stripped for F-Droid by `support/scripts/remove_proprietary_dependencies.sh`, which relies on the `# [FOSS_REMOVE]` pubspec marker and `// [FOSS_REMOVE_START]` / `// [FOSS_REMOVE_END]` comment pairs. Preserve those markers when editing `lib/config/init.dart`, `lib/pages/donation/*`, or `lib/provider/purchase_provider.dart`.
+
+## Release notes
+
+`app/pubspec.yaml`'s version must match `#define MyAppVersion` in `support/scripts/compile_windows_exe-inno.iss` — CI fails on a mismatch. Platform build commands and release steps are documented in `README.md` ("Building") and `CONTRIBUTING.md` ("Release").

CONTRIBUTING.md

@@ -2,6 +2,12 @@
 
 LocalSend is an open-source project, and we welcome contributions from anyone who is interested in helping improve the app. Whether you're a developer, a translator, or a documentation writer, there are many ways to get involved.
 
+LocalSend disallows AI generated contributions unless:
+
+- they are bug fixes or
+- very small or
+- you prove your expertise in your field
+
 ## Getting Started
 
 If you're interested in contributing code to LocalSend, you'll need to follow these steps:

app/.mcp.json

@@ -0,0 +1,13 @@
+{
+  "mcpServers": {
+    "dart-mcp-server": {
+      "command": "dart",
+      "args": [
+        "mcp-server"
+      ]
+    },
+    "slang_mcp": {
+      "command": "slang_mcp"
+    }
+  }
+}