crabidy/README.md

# crabidy

A client/server music player. A headless gRPC server owns the library,
the play queue, and audio output; a terminal UI connects to it over
localhost (or the network). Media comes from pluggable **providers**,
each mounted as a subtree of one library:

```text
/
├── tidal        Tidal streaming (see tidaldy/README.md)
├── youtube      YouTube search & playlists (see ytdy/README.md)
├── fs           a local music folder (see fsdy/README.md)
├── crabidy      your saves: queues, bookmarks (`w`), and captures (`W`),
│                managed by the server (see architecture/crabidy-store.md)
└── orphans      store audio no save references any more — rename, delete,
                 or queue it (see architecture/orphans.md)
```

## Binaries

- `crabidy-server` — the server: providers, queue, playback, gRPC on
  `0.0.0.0:50051`. Also serves the web client at that address (see
  below).
- `cbd-tui` — the terminal client. Press `?` inside for all key
  bindings.
- `cbd` — both in one process: starts the server, waits until it
  accepts connections, then runs the TUI. Adopts an already-running
  server instead of failing on an occupied port.
- `cbd-web` — the browser client (Leptos/WASM), with the same
  functionality as the TUI. Not run directly: it is built to a bundle
  and embedded into `crabidy-server` (see
  [cbd-web/README.md](cbd-web/README.md)).

## Quick start

The toolchain is managed by [devenv](https://devenv.sh):

```sh
devenv shell          # provides rust, yt-dlp, and friends
cargo run -p cbd      # server + TUI in one process
```

Or run the halves separately: `cargo run -p crabidy-server` and, in
another terminal, `cargo run -p cbd-tui`.

## Configuration

All configuration lives in `~/.config/crabidy/` (the platform config
directory). Every file is optional; missing providers simply do not
mount. Files are created/rewritten on first start with their defaults
filled in.

| File                 | Component  | Documentation                          |
| -------------------- | ---------- | -------------------------------------- |
| `tidaly.toml`        | Tidal      | [tidaldy/README.md](tidaldy/README.md) |
| `ytdy.toml`          | YouTube    | [ytdy/README.md](ytdy/README.md)       |
| `fsdy.toml`          | local fs   | [fsdy/README.md](fsdy/README.md)       |
| `cbd-tui.toml`       | `cbd-tui`  | below                                  |
| `cbd.toml`           | `cbd`      | below (same options as `cbd-tui.toml`) |
| `crabidy-server.toml`| server     | below (providers + auth)               |

The server-managed `crabidy` provider does not live under `~/.config`. Its
track-file tree (saved queues, bookmarks, and captures) lives in
`~/.local/state/crabidy/` (the platform *state* directory) and the audio it
captures lives in a single content-addressed store under
`~/.local/share/crabidy/` (the *data* directory), shared and de-duplicated
across saves. Neither needs configuration; see
[architecture/crabidy-store.md](architecture/crabidy-store.md).

### `cbd-tui.toml` and `cbd.toml`

Client configuration. `cbd-tui` (the standalone terminal client) reads
`cbd-tui.toml`; `cbd` (server + TUI in one process) reads its own
`cbd.toml`. They are **separate files with the same options** so the two
can run side by side on one machine — a common setup is `cbd` playing
locally against its in-process server while `cbd-tui` points at a remote
server (e.g. a Raspberry Pi). A shared file would force one to follow
the other's `address`.

```toml
[server]
# Where to find the server. Default (both files): localhost, which is
# what cbd's own in-process server listens on. Point cbd-tui.toml at a
# remote server to use it as a remote control.
address = "http://127.0.0.1:50051"

# Credentials, when the server has [auth] configured (see below).
# `user` is the role name; leave both empty against an open server.
# The password is stored in plaintext — keep this file private.
user = ""
password = ""

# Show the frequency-spectrum bars under the track progress. Default true.
spectrum = true
```

Every option is also available as a command-line flag before the
subcommand (`cbd-tui --address ... --user owner`, `cbd --spectrum
false`); a flag overrides the file value. To write the credentials into
the config once, use the `auth` subcommand (see below) instead of
editing the file by hand:

```sh
cbd-tui auth owner 'my-password'                 # sets user + password
cbd-tui auth queue-owner 'pw' --address http://pi:50051
```

### `crabidy-server.toml` — providers and rights

On first start the server writes this file with every provider enabled:

```toml
providers = ["tidal", "youtube", "fs", "crabidy", "orphans"]
```

**Remove a name to disable that provider** — it no longer mounts and does
not appear in the library. Deleting the whole `providers` line re-enables
everything (a fresh install with no file behaves the same). Disabling
`crabidy` also drops `orphans`, which is a view over the store. A disabled
provider's own config file (`tidaly.toml`, etc.) is simply left unread.

#### Roles and rights

By default the server is open: everyone who can reach the port has
full control. Adding an `[auth]` section turns on HTTP basic auth for
every RPC and hands out *roles* (see `architecture/roles-auth.md`):

- **owner** — everything (the normal user).
- **queue-owner** — anything on the queue and playback, but no
  library writes: no bookmarks (`w`), captures (`W`), queue saving,
  renames or deletes.
- **queue-appender** — may browse/search and append tracks to the
  queue; nothing else.

```toml
[auth]
# One PHC hash per role; omit a role to disable it. Generate and store
# a hash with:  crabidy-server guard <role>  (see the CLI section).
owner = "$argon2id$v=19$m=19456,t=2,p=1$..."
queue_owner = "$argon2id$..."
queue_appender = "$argon2id$..."
```

Clients authenticate with the role name as the basic-auth user (see
`cbd-tui.toml` above). A malformed `crabidy-server.toml` aborts server
startup rather than silently running open. Note that the transport is
plain HTTP/2: fine on a trusted home network, but anything exposed
further needs TLS termination (reverse proxy, VPN) in front.

## Command line

Every binary is a clap CLI: run it with `--help` (and any subcommand
with `--help`) for the full surface. Running a binary with **no
subcommand** behaves as it always has — `crabidy-server` runs the
server, `cbd-tui` runs the TUI, `cbd` runs the in-process server + TUI.

The `library`, `queue`, and `global` subcommands are available on all
three binaries and act as a remote control over gRPC (they connect to a
running server, honouring the same `[auth]` credentials as the TUI):

```sh
crabidy-server library list /tidal      # browse a node
cbd-tui --address http://pi:50051 queue append /fs/album
cbd global play                          # toggle play/pause
cbd global volume -- -0.1                # lower the volume
```

Connection flags (`--address/--user/--password`) go **before** the
subcommand; omitted, they fall back to the client config file.

Server-only subcommands (`crabidy-server`, and `cbd`):

- `guard <role> [password]` — hash a role password (argon2id), print
  the PHC string, and (unless `--no-config`) write it into
  `crabidy-server.toml`'s `[auth]`. Roles: `owner`, `queue-owner`,
  `queue-appender`.
- `scan <path> [--capture|--move]` — walk a folder and drop a
  `.cbd-track.toml` beside every audio file so it browses under `/fs`.
  `--capture` copies each file into the content store (the toml points
  there); `--move` moves it instead of copying.

Client-only subcommand (`cbd-tui`, and `cbd`):

- `auth <role> [password] [--address ADDR]` — write the role name and
  cleartext password (and address) into the client config.

**Password caveat.** A password given as a command-line argument is
visible in the process list (e.g. `ps`). Omit it and `guard` reads the
password from stdin instead, which keeps it out of argv and is
pipe-friendly:

```sh
printf '%s' 'my-password' | crabidy-server guard owner
```

The client config stores the password in plaintext, so keep the file
private.

### Completions and man pages

```sh
cbd-tui completions bash                 # print a completion script
devenv shell -- gen-cli-assets           # write dist/completions + dist/man
```

`gen-cli-assets` builds the binaries with `CBD_ASSET_DIR=$PWD/dist`, so
`dist/completions/**` (bash/zsh/fish) and `dist/man/*.1` are produced
for all three binaries. Every ordinary build also emits them into the
crate's `OUT_DIR`.

## Using the library

Navigation is vim-style: `j`/`k` select, `l` enters the selected
folder, `h` goes to the parent, `Tab` switches between library and
queue, `Enter` replaces the queue with the selection. `%` creates a
node where the pane title shows `% to add` (e.g. a search term), `e`
renames, `d` deletes. `/` filters the current pane (library or queue)
live as you type — `Enter` keeps the filter, `Esc` clears it.

- `w` saves the selection (a library subtree, or in the queue pane the
  queue) as a new folder under `/crabidy/<name>` of **link** files —
  needs the source provider to replay. On a name that already exists the
  save is refused with a warning; delete the old folder and save again.
- `W` **captures** the selection into `/crabidy/<name>`: same as `w`, but
  every track's audio is fetched into the shared content store under
  `~/.local/share/crabidy/` and the saved tomls link to it — fully local
  playback afterwards. Works on a library subtree and on the queue (no
  need to save it first). Audio is **de-duplicated**: capturing the same
  track again (from a playlist, a search, another save) reuses the stored
  file instead of downloading it twice, matched first by provider id and
  then by content hash. Tracks already local (from `/fs`) are copied into
  the store rather than re-downloaded. A source that genuinely cannot be
  captured is recorded as *skipped* (red in the UI, skipped by playback).
  Download captures can take long; progress is shown in the library pane.
- Captured rows are marked with a trailing `↓` (down-arrow) at the end of
  the row — visible even while browsing another provider, so you can see
  what you already have.
- Inside `/crabidy`, `d` deletes a folder or track immediately (no
  confirmation): it removes only the metadata toml, never the shared store
  audio, which other saves may reference.

Press `?` for the full binding table.

A row of frequency-spectrum bars is drawn under the track progress
while audio plays (the server taps its own output, runs the FFT, and
streams the bars, so it works whether the server is local or remote).
Toggle it at runtime with `v`, or set the startup default with
`spectrum = false` in the client config.

## Web client

`crabidy-server` serves a browser client with the same functionality as
the TUI at its own address (`http://<server>:50051/`) — same navigation,
same keys (`j`/`k`/`h`/`l`, `%`, `e`, `d`, `w`, `W`, queue and playback
controls, `?` for help), plus clickable equivalents and a light/dark
theme toggle. It talks gRPC-web to the same service the TUI uses, so it
honors the same `[auth]` roles (it shows a login form when the server
requires credentials).

It is compiled to a WASM bundle and embedded into the server binary,
behind the default-on `web-ui` cargo feature. A plain `cargo build`
needs no WASM toolchain — it embeds a "not built" placeholder page until
you build the bundle:

```sh
devenv shell -- build-web        # writes cbd-web/dist
cargo build -p crabidy-server    # embeds it
```

Build the server with `--no-default-features` for a headless,
gRPC-only binary. See [cbd-web/README.md](cbd-web/README.md) for the
dev loop and details.

## Nix packages and cross-compiling

`flake.nix` (built with [crane](https://github.com/ipetkov/crane)) packages
the binaries as Nix derivations — for your own machines, and cross-compiled
for a Raspberry Pi. No Docker required.

Native — install on any machine with Nix:

```sh
nix run .#cbd-tui                 # run without installing
nix build .#crabidy              # cbd, cbd-tui, crabidy-server → ./result/bin
nix profile install .#crabidy    # or github:OWNER/crabidy once pushed
```

Raspberry Pi (or any aarch64 Linux) — a fully **static musl** binary, so it
has no glibc-version or loader dependency and runs on stock Raspberry Pi OS
(bookworm and newer):

```sh
nix build .#crabidy-server-aarch64
scp ./result/bin/crabidy-server pi:/usr/local/bin/
```

Nix cross-compiles the Rust *and* the C dependencies (ALSA, aws-lc)
hermetically on an x86_64 host — the isolated build avoids the host-linker
pitfalls of cross-compiling in a plain shell. The aarch64 server **includes
the embedded web UI**: the flake builds the `cbd-web` wasm bundle with trunk
(pinning a `wasm-bindgen` CLI that matches the crate) and stages it into the
server's `web-ui` feature. The native `.#crabidy` package stays headless; use
a normal `cargo build` there if you want the bundle.

A container-based `cross` setup also exists (`Cross.toml` + the
`*-Dockerfile`s) for building against Debian's glibc, but the flake is the
recommended path.

## Logs

`cbd` and `cbd-tui` log to `~/.local/state/crabidy/` (daily files);
`crabidy-server` logs to stderr. Stream URLs and credentials are
redacted from logs by design.

## Development

Design documents live in `architecture/`, per-feature quality gates in
`quality/`, and implementation plans in `plan/`. See `CLAUDE.md` /
`AGENTS.md` for the development workflow and coding rules.