# carrier

A minimalist desktop client for [Smol Mail](../smolmail): one compact window — the list above, the article below — built on [fumi-core](../fumi), the reference CLI's own library, with a [Relm4](https://relm4.org) (GTK4) UI built from libadwaita's own widgets, so it follows the user's theme and accent colour. One 32-byte seed is the only secret; mail stays sealed at rest and opens on demand.

## What it does

- Create or restore an identity from a seed, shown once at creation time.
- Pin a server's key — paste the operator's, or connect and pin what it presents — then register a username or recall an existing address.
- Fetch (with cancel), read, reply and send sealed mail; the inbox, the requests tier and sent copies each keep their own folder.
- Composes closed by any sidebar trip are stashed as drafts — kept beside the store, reopened from a folder that appears only once one exists; Cancel is the only way to throw one away.
- Custom `Key: value` frontmatter rows when writing: one line per header under the subject, validated against the frontmatter rules — the client's own fields (subject, reply-to, in-reply-to, accept) can't be shadowed, and rows survive a stash as part of the draft. Received mail shows the sender's own fields in the message detail, between the meta line and the body; replying to such a mail asks whether to carry copies of the fields into the reply, where they stay editable.
- Accept or block a requester when their mail carried a self-certifying reply address; accept tokens attach to accepted contacts automatically.
- Contacts with verified/tofu marks and smol:// import; your own identity opens in the same detail view, its address in the header bar with a QR share beside it, key, fingerprint and URI below.
- Key rotation with a confirm-first step, server pin management, a network timeout, gsmol backup export/import that never contains the seed, and a factory reset that erases the local files and returns to onboarding.

## Layout

```
src/main.rs   config directory, demo seeding, launch
src/app.rs    state and update; blocking calls run on the worker pool
src/view.rs   the Relm4 component: widgets, the op adapter, the re-render
src/ops.rs    fumi-core calls, key/read-mark files, and the offline tests
```

## State

Everything lives under `$XDG_CONFIG_HOME/carrier` (default `~/.config/carrier`): `carrier.key` is the master seed, written 0600; `carrier.db` is fumi-core's sealed store; `read.txt` is carrier's own read marks, one hex id per line.

## Run and verify

```
devbox run run      # build release and launch
devbox run check    # fmt --check, build, tests
devbox run test     # tests only
```

The tests run offline against an in-memory store: seed and key parsing, a sealed envelope listed and opened end to end, contact import, a full backup round-trip, pin labels and the date formatter. `scripts/devbox-libs.sh` puts the GUI stack's runtime libraries (wayland, xkbcommon, EGL, vulkan) on the library path inside the devbox shell — they are dlopened, so nothing that links the binary can provide them.

## Status

Work in progress: the UI is unexercised against a live server — the store, crypto and address paths are covered by tests, the network flows (register, fetch, send, rotate) are wired to fumi-core's operations but only smoke-tested as far as launching the window.

## Packaging

`devbox run package` builds and installs the app as a Flatpak from
`com.randogoth.carrier.json` — the binary, the desktop file, the metainfo and
the icon all come from the repo, and the tooling (`flatpak`, `flatpak-builder`,
`appstreamcli`) lives in the devbox environment. The flatpak runtime is the one
dependency outside devbox; install it once:

    flatpak install --user flathub org.gnome.Sdk//51 org.freedesktop.Sdk.Extension.rust-stable//26.08

The result is installed into the user flatpak and runs as
`flatpak run com.randogoth.carrier`. Inside the sandbox the app keeps its
config under `~/.var/app/com.randogoth.carrier/config/carrier`, so a flatpak
install starts with a fresh identity rather than the dev build's account.

### Windows

Install MSYS2 (`winget install MSYS2.MSYS2`), open the **MSYS2 MINGW64**
shell, and run the one-command script from the carrier checkout:

    git clone ssh://git@code.randogoth.com:2222/randogoth/carrier.git
    cd carrier && windows/setup.sh

`windows/setup.sh` installs the GTK and Rust stack into MSYS2, clones fumi
next to carrier if it is missing, builds, and bundles carrier.exe with the
GTK runtime into `dist/` and a zip — the complete Windows distribution. The
app keeps its config in `%APPDATA%\carrier`. If MSYS2 updates its core
mid-run the shell may close; rerun the script and it continues. Cloning
over SSH needs the key in `~/.ssh` inside the MSYS2 home.