somafm-tui

A flashy terminal radio for SomaFM — a live spectrum analyser, song history, and full desktop media integration, drawn with your terminal's own ANSI palette on the terminal's default background so it fits any theme (including transparent terminals).

It runs the same way on Linux (PulseAudio/PipeWire) and macOS (CoreAudio, iTerm2/Kitty/WezTerm): MPRIS on the desktop bus where that exists, macOS Now Playing (Control Center and the media keys) where it does not.

No existing SomaFM client is used: the station list, playlists, song history, audio control, spectrum visualiser and media-session integration are all implemented here from the public SomaFM endpoints and open protocols.

Features

• Live spectrum analyser — 72 log-spaced bands with peak caps, a moving gradient taken from your terminal's ANSI palette and a symmetric mirrored spectrum; or a full-height oscilloscope. Three modes (v).
• Synced spectrum, not a guess — by default the analyser records your actual audio output, so the bars follow what you hear (SYNC): the PulseAudio/PipeWire monitor via parec on Linux, and a native Core Audio process tap on macOS (no driver, no BlackHole, nothing to install). Without an output capture it falls back to a muted second ffmpeg decode of the stream (FFT, can drift), then to a synthesized display (SIM).
• Real artwork on iTerm2, Kitty and WezTerm — Kitty uses the kitty graphics protocol; iTerm2 (including on macOS) and WezTerm use their native iTerm2 inline-image protocol. Images occupy exactly the ON AIR art cell box and fall back to the procedural ANSI mosaic for other terminals, failed loads, or blocked graphics passthrough. Images are cached in ~/.cache/somafm-tui/artwork.
• Now playing — artist, title, album, DJ, listeners, format/bitrate and "played N minutes ago", with procedural ANSI-shaded album art that changes per track. When the current track can be found on Bandcamp, a clickable Bandcamp ↗ link appears below it; otherwise the line stays hidden.
• Last played — the full recent history from somafm.com/songs/<id>.json.
• Every station — the whole channels.json roster (≈50 channels), live listener counts, genre search.
• Favourites that float to the top, remembered between runs.
• Desktop media integration — on Linux an org.mpris.MediaPlayer2.somafmtui.instance<pid> player exposes PlaybackStatus, Metadata (title/artist/album/artUrl), Volume, and Play/Pause/PlayPause/Stop/Next/Previous, so GNOME/KDE widgets, lock screens, playerctl and the media keys pick it up. On macOS the audio engine (mpv) publishes to the system Now Playing session, so Control Center, the menu bar and the keyboard media keys drive the app the same way.
• Theme-aware — every accent is emitted as native ANSI (not RGB), and the background is the terminal default (SGR 49), so transparent terminals stay transparent and the TUI adopts your shell/terminal colour scheme.
• Graceful degradation — works with cached data offline, falls back to a bundled station list, reconnects across ICE mirrors automatically, and uses ffplay if mpv is missing.

Requirements

somafm-tui is a normal Python application: there is nothing to compile and no distro-specific packaging. It runs on any Linux distribution or macOS with Python 3.10+ and a few command-line audio tools on $PATH.

tool	why
python3	runtime (3.10 or newer; no exact version pin)
uv	creates the venv and installs every Python dependency from uv.lock
mpv	playback and JSON IPC control
ffmpeg	muted stream decode for the fallback analyser
parec / pactl (Linux)	synced monitor capture for the spectrum (pulseaudio-utils; works with PipeWire)
D-Bus session bus (Linux)	MPRIS desktop media integration (playerctl is handy for testing)

On macOS the spectrum capture is part of the app: it uses the Core Audio process-tap API (macOS 14.2 or newer), so there is no loopback driver to install.

On macOS the media integration needs nothing extra: mpv is what the system's Now Playing session (Control Center, media keys) talks to.

Install uv once (skip if it is already there):

curl -LsSf https://astral.sh/uv/install.sh | sh

brew install uv, pipx install uv, or a distro package also work. If your system Python is older than 3.10, let uv manage one: uv python install 3.12.

Linux

Install these with your package manager. Names are usually:

# Debian / Ubuntu
sudo apt install python3 mpv ffmpeg pulseaudio-utils dbus playerctl

# Fedora (enable RPM Fusion for ffmpeg if needed)
sudo dnf install python3 mpv ffmpeg pulseaudio-utils dbus-tools playerctl

# Arch / Manjaro
sudo pacman -S python mpv ffmpeg libpulse dbus playerctl

# openSUSE
sudo zypper install python3 mpv ffmpeg pulseaudio-utils dbus-1-tools playerctl

For other distributions, install the equivalents. On a headless machine you can skip the audio/D-Bus tools and use --no-audio for a UI-only demo, though the synced spectrum needs parec/pactl.

macOS

brew install mpv ffmpeg uv        # ffplay ships with ffmpeg

That is enough to run: playback, artwork in iTerm2/Kitty/WezTerm, the synced Core Audio spectrum tap and the macOS Now Playing integration all work out of the box.

The first time the analyser starts it asks macOS for System Audio Recording permission — a one-off prompt for your terminal (iTerm2, Kitty, WezTerm, …). Approve it under System Settings → Privacy & Security → System Audio Recording; no loopback driver, Multi-Output Device or audio routing is needed. If the permission is denied the tap only ever hands out silence, the analyser notices and falls back to FFT instead of showing dead bars.

The tap records the default output device, which is also what mpv uses; if you point mpv elsewhere with SOMAFM_MPV_ARGS='--audio-device=...' the analyser falls back to FFT.

Terminal image rendering uses Pillow and is implemented directly (Kitty TGP + iTerm2 OSC 1337) — no terminal probing.

Run

From the repository root, sync the environment and start the app:

uv sync              # create .venv and install exactly what uv.lock pins
uv run somafm-tui    # run inside that environment

You do not need to activate the venv. uv run uses .venv automatically, and re-syncs it first if pyproject.toml or uv.lock changed. If you prefer a traditional shell, run source .venv/bin/activate and then somafm-tui.

Keeping the uv environment in sync

uv sync is the command to remember. It is incremental, safe to re-run, and should be run after pulling changes, switching branches, or editing pyproject.toml:

uv sync                  # make .venv match uv.lock
uv sync --frozen         # strict: fail if uv.lock is out of date, never rewrite it
uv lock --upgrade        # refresh uv.lock to the newest allowed versions
uv sync --upgrade        # upgrade dependencies and sync .venv in one step
rm -rf .venv && uv sync  # last resort if the venv was built by an older Python

Useful flags:

uv run somafm-tui --play                # start the last station immediately
uv run somafm-tui --station defcon       # pick a station
uv run somafm-tui --volume 55
uv run somafm-tui --offline              # no network; cached/bundled stations
uv run somafm-tui --no-mpris             # no MPRIS / Now Playing, no media keys
uv run somafm-tui --list                 # print station ids
uv run somafm-tui --no-audio             # UI demo without mpv/ffmpeg
uv run somafm-tui --spectrum-source monitor  # force synced output capture
uv run somafm-tui --spectrum-source stream   # force the muted ffmpeg tap
SOMAFM_IMAGES=0 uv run somafm-tui             # force the ANSI artwork mosaic
SOMAFM_IMAGES=tgp uv run somafm-tui           # force Kitty/TGP artwork
SOMAFM_IMAGES=iterm2 uv run somafm-tui        # force iTerm2/WezTerm artwork

The UI wants roughly 84×24; it also works smaller, just less pretty.

Keys

key	action
↑ / ↓, j / k	move through stations
enter	tune in to the selected station
space	play / pause
s	stop
] / [	next / previous station (tunes immediately)
+ / -	volume
m	mute
f	favourite (favourites sort to the top)
/	filter by title, genre, description
esc	clear filter / close search
v	visualiser: mirrored bars → bars → wave
r	refresh channels + song history
g / G	top / bottom
?	help
q	quit

Desktop media widgets (MPRIS / Now Playing)

Linux — while playing, the app exports org.mpris.MediaPlayer2.somafmtui.instance<pid> on the session bus. Check it:

playerctl -l
playerctl metadata --format '{{artist}} — {{title}} ({{album}})'
playerctl play-pause

mpris:artUrl is the track's album art when SomaFM provides it, otherwise the channel logo. If there is no session bus (SSH without dbus-run-session, containers, …) MPRIS is skipped and the status bar shows mpris off.

macOS — mpv owns the system Now Playing session, so Control Center, the menu-bar widget and the keyboard media keys (▶︎/⏸, ⏭, ⏮) all target this app while it is playing. mpv publishes the live stream title (the same “Artist - Title” that SomaFM sends with the audio), and the media keys are routed back into the TUI, so ⏭/⏮ really change station and the panel, the spectrum and the station list stay in sync. The status bar shows nowplaying on. There is no D-Bus and no extra dependency involved, and --no-mpris (also spelled --no-media) turns the media keys off again.

macOS shows one Now Playing app at a time. If Music/Safari/another mpv is playing, the media keys go there instead — quit it or pause it to hand the keys back.

How it works

• somafm_tui/api.py — async httpx client for:
  • channels.json → stations, genres, listeners, .pls playlist URLs
  • <station>.pls → resolved direct icecast URLs (cached 8h)
  • songs/<station>.json → last played tracks (cached on disk) Playlist and channel caching means the UI opens instantly and still works offline.
• somafm_tui/player.py — mpv over a Unix-socket JSON IPC channel. Observes pause/volume, handles mirror failover on end-file, auto-restarts a dead engine, and uses SIGSTOP/SIGCONT when falling back to ffplay. On macOS it also asks mpv to publish Now Playing and maps the media keys onto script-messages that come back over the same IPC socket.
• somafm_tui/spectrum.py — analyser (44.1 kHz mono s16le from parec, or the device's native float32 rate from the macOS tap). Prefers capturing the real output: parec (PulseAudio/PipeWire monitor) on Linux, or a native Core Audio process tap on macOS (SYNC, see macos_tap.py). Otherwise a muted low-latency ffmpeg decode of the stream (FFT). Hann-windowed 2048-point FFT, log band grouping, auto-gain, fast attack/decay smoothing, peak hold and waveform downsampling.
• somafm_tui/macos_tap.py — the macOS output capture, in pure ctypes against Core Audio: CATapDescription → AudioHardwareCreateProcessTap → private aggregate device → IOProc. No driver, no helper binary, no ffmpeg.
• somafm_tui/mediasession.py — picks the desktop media backend (MPRIS on Linux, Now Playing on macOS) so the app has one platform-neutral interface.
• somafm_tui/mpris.py — dbus-next MPRIS service in its own thread with a thread-safe command queue back into the UI (only loaded on D-Bus platforms).
• somafm_tui/bandcamp.py — searches Bandcamp's public autocomplete API for the now-playing track (artist + track first, then artist + album, then the album page) and returns a track URL when there is a match.
• somafm_tui/widgets/ — Textual widgets rendered with native ANSI colours; backgrounds are ansi_default (SGR 49), so transparent terminals stay transparent.

Files

~/.config/somafm-tui/config.json     favourites, volume, last station, mode
~/.cache/somafm-tui/channels.json    last good station list
~/.cache/somafm-tui/playlists.json   resolved stream URLs
~/.cache/somafm-tui/songs/<id>.json  song history snapshots
~/.cache/somafm-tui/artwork/<sha1>  cached album/channel artwork

These stay in the XDG locations on every platform (macOS included), so the same dotfiles/config work everywhere; XDG_CONFIG_HOME, XDG_CACHE_HOME and XDG_RUNTIME_DIR are honoured when set.

Notes / troubleshooting

• Artwork shows the mosaic? Real images are auto-enabled for Kitty, iTerm2 and WezTerm. Force a protocol with SOMAFM_IMAGES=tgp (Kitty/TGP) or SOMAFM_IMAGES=iterm2 (iTerm2/WezTerm); SOMAFM_IMAGES=0 forces the ANSI mosaic. iTerm2 on macOS is detected from TERM_PROGRAM/LC_TERMINAL, and empty or 0 values in TMUX/ZELLIJ/STY (exported by some wrappers) are ignored so they cannot downgrade it. Kitty inside tmux is attempted through tmux passthrough (enable set -g allow-passthrough on); iTerm2/WezTerm inside tmux default to the mosaic. Images are cached under ~/.cache/somafm-tui/artwork.
• Clock shows UTC? The clock and song history use the system zone from /etc/localtime; a non-UTC TZ overrides it. A container or dev shell can inherit a build-time TZ=UTC, which the app deliberately ignores; bind the host's /etc/localtime or set e.g. TZ=Europe/Berlin in the shell that launches the app.
• MPRIS says off/error? No session bus. Run from your desktop session (the shell profile picks up $XDG_RUNTIME_DIR/bus). dbus-run-session -- uv run somafm-tui starts a private bus for testing, but desktop widgets won't see it. macOS does not use MPRIS at all — see “Now Playing” above.
• No audio? somafm-tui needs mpv (preferred) or ffplay. Without either, the UI still runs and tells you. Extra mpv args can be injected with SOMAFM_MPV_ARGS (e.g. SOMAFM_MPV_ARGS='--audio-device=...', which is the macOS way to choose an output device).
• Spectrum says FFT instead of SYNC? The monitor is unavailable or failed, or you forced the stream tap. The bars are still real audio, but the second stream can drift relative to playback. Use --spectrum-source monitor to force sync, or SOMAFM_SPECTRUM_DEVICE=<source> on Linux to pick a specific monitor. SIM means the bars are synthesized.
• Diagnose artwork: uv run somafm-tui --diagnose-images prints the detected protocol, widget class, terminal env, dependency versions and cache path. If protocol is None, force it with SOMAFM_IMAGES=tgp (Kitty) or SOMAFM_IMAGES=iterm2 (iTerm2/WezTerm).
• SYNC but the bars are flat? mpv may be playing to a different sink (or directly to ALSA). Point SOMAFM_SPECTRUM_DEVICE at that sink's monitor, or use --spectrum-source stream.
• macOS: spectrum stays FFT? Grant your terminal System Audio Recording permission (System Settings → Privacy & Security → System Audio Recording), then restart the app; the status bar explains when the tap is silent because of this. Also check that mpv is playing to the default output device, since that is what the tap records.
• macOS: media keys do nothing? Another app currently owns the Now Playing session, or the app was started with --no-mpris, or the audio backend fell back to ffplay (mpv is required for Now Playing). The status bar shows nowplaying on when the integration is armed.
• macOS: Control Center shows only a title? mpv publishes the stream's live “Artist - Title” as the Now Playing title; artist/album fields and artwork are not filled in by macOS for plain audio streams. The TUI itself always shows the full metadata and album art.
• Bandwidth is unchanged in SYNC mode (the monitor capture creates no second stream). The FFT fallback opens one extra stream; if you are on a metered link, use --spectrum-source monitor (or --no-audio for a UI-only demo).
• SomaFM is listener-supported: if you enjoy it, donate.

NixOS (optional aside)

None of the above needs Nix. If you are on NixOS, shell.nix wraps the same uv sync / uv run workflow in an FHS environment, because uv installs manylinux wheels such as NumPy that expect libstdc++.so.6 in the usual /usr/lib paths:

nix-shell            # enter the FHS dev shell
uv sync
uv run somafm-tui

• If you see libstdc++.so.6: cannot open shared object file, make sure you are inside nix-shell, then recreate the venv once with rm -rf .venv && uv sync.
• nix-shell --run "..." does not work with FHS shell.nix files; enter the shell interactively and run commands there.
• FHS shells need unprivileged user namespaces. bwrap: No permissions to create a new namespace means they are disabled (for example in a locked-down container); run the app on the host instead.

Licence

WTFPL — Do What The Fuck You Want To Public License, Version 2. See LICENSE. SomaFM and its channel names are trademarks of SomaFM.com, LLC.

Terminal image rendering uses Pillow.