Start here

Quick start

1
Install the Mac app
Open the notarized DMG, drag Carthios into Applications, eject the DMG, then launch the installed copy.
2
Connect Car Thing with a data cable
The first setup and every dashboard/firmware update require USB data—not a charge-only cable.
3
Complete the first-run walkthrough
Carthios installs the matching dashboard automatically and explains music, Weather, dictation, Transit, Agenda, and optional permissions.
4
Choose optional features
Use the Carthios menu-bar icon and Car Thing Settings for Bluetooth Beta, Weather on Clock, Calendar & Reminders, Transit, Dictation, launch at login, and advanced Spotify.

Connection

USB and Bluetooth Beta

Capability	USB	Bluetooth Beta
Music, Weather, Agenda, Transit, timers, system data	Yes	Yes
Initial setup and dashboard/firmware updates	Required	No
Car Thing microphone and dictation	Required	Not yet
Screenshots and recovery	Required	No
Mac sleep and lock brightness mirroring	Yes	Yes

USB is preferred, but a physical cable alone does not prove that data is working. Carthios keeps or restarts paired Bluetooth while it checks the cable, then stops Bluetooth only after USB is authenticated or its ADB tunnel is ready. If USB disconnects or becomes unusable, Bluetooth can take over again automatically.

Hardware

Physical controls

Dial

Turn for volume in ten steps. Press for the current page action. Hold Home while turning to adjust brightness.

Home

Press to open Clock. Hold to dictate; recording begins on hold and stops on release.

Preset 1

Press for Now Playing. Hold for Spotify playlists when advanced Spotify is connected.

Preset 2

Press for Pomodoro. Hold for Agenda.

Preset 3

Open the selected Claude Code or Codex monitor.

Preset 4

Press for nearby Transit. Hold for Weather.

Top-right button

Press for Dashboard. Hold for Mac and Car Thing system status.

Screenshot shortcut

Hold Home and the top-right button together. Screenshots require USB.

Product

Feature guide

Spotify Desktop

Artwork, progress, play/pause, skip, seek, shuffle, repeat, podcast seeking, and volume work with the Spotify Mac app already signed in.

Apple Music

Use the same Now Playing screen for songs and Radio, with artwork and metadata when Music provides them, progress, play/pause, skip, seek, shuffle, repeat, and ten-step volume.

Advanced Spotify

Optional Spotify authorization adds account-scoped likes, queue, playlists, following, and Spotify Connect where Spotify supports them.

Weather

Current conditions, hourly details, and a four-day outlook use the Mac’s coarse location. While Weather remains open, Car Thing requests an update every minute; the Mac honors the forecast response’s expiry time and returns its RAM cache until a new provider fetch is allowed. Current conditions can also appear on Clock.

Transit

Nearby rail and bus departures with refresh time and RAM caching. Supported integrations include MTA, MBTA, WMATA, BART/511, CTA, SEPTA, and TriMet. Some bus sources require a free API key.

Agenda

Upcoming events use their matching macOS Calendar colors. Overdue and due-today reminders appear alongside them and can be completed on Car Thing.

Pomodoro and Clock

A deadline-based timer that survives navigation, a Mac-synchronized clock, offline fallback, and synchronized music progress.

Coding monitor

Choose Claude Code or Codex to see active/recent sessions, completion state, and supported usage warnings.

System monitor

Mac CPU, memory, disk, and battery plus Car Thing temperature and uptime.

Device settings

Brightness, auto brightness, Mac sleep and lock mirroring, time display, Bluetooth controls, first-time setup, recovery, and firmware repair.

Calendar + Reminders

What “Calendar Only” and “Reminders Only” mean

Agenda requests Calendar and Reminders separately. Calendar Only means Calendar access is granted but Reminders is denied or unavailable. Reminders Only means the reverse. Carthios still shows everything macOS permits; the missing half stays empty.

This label does not mean Carthios selected only certain calendars. Open the Carthios menu-bar icon → Calendar & Reminders, then use the Calendar or Reminders action in that submenu. If macOS has never asked, Carthios shows the native consent prompt. If access was already denied, it opens the matching Privacy & Security page. Carthios refreshes the status when you return.

Agenda sends only titles, times, all-day state, display colors, reminder priority, and completion identifiers to Car Thing. Notes, attendees, calendar names, and long-term history are excluded.

Voice

Push-to-talk dictation

1. Click the Mac text field where the result should go.
2. Hold the Car Thing Home button and begin speaking when the listening state appears.
3. Release Home to stop recording and transcribe.

English (US) recognition stays on the Mac. Accessibility is used only for automatic insertion. If it is declined, the finished transcript is copied to the clipboard and Car Thing explains that you can paste it. Smart Cleanup is optional, off by default, Apple Silicon–only, and uses Apple’s supported on-device intelligence path when available.

Privacy

Permissions explained

Automation

Controls the Spotify or Apple Music desktop app you select. macOS may ask the first time Carthios talks to that app.

Speech Recognition

Turns Car Thing microphone audio into text locally on the Mac.

Accessibility

Optional. Inserts finished dictation into the selected text field; clipboard fallback remains available without it.

Bluetooth

Pairs and reconnects to Car Thing wirelessly.

Location

Requests local Weather and finds nearby Transit stops. Forecast requests send coordinates rounded to four decimal places to MET Norway over HTTPS. Location is not used for advertising or diagnostics.

Calendars and Reminders

Optional and separate. Powers Agenda only after the user enables it.

Keychain

Stores Spotify and Transit credentials. A repeated password prompt can indicate that the app’s signing identity or saved item access changed.

Files on removable volumes

Not required for normal use. If macOS asks, quit the copy running from the DMG/external drive, drag Carthios to Applications, eject the installer, and launch the installed app.

Optional product diagnostics are separate from macOS permissions and remain off until you enable them. They can record coarse use of Music, Agenda, and Dictation, but never dictated text or audio, music metadata or history, Calendar or Reminder content, credentials, paths, locations, or device identifiers. Read the complete privacy policy.

Display

Dim When Mac Sleeps or Locks

Open the Carthios menu-bar icon → Car Thing → Dim When Mac Sleeps or Locks. When enabled, an authenticated Mac sleep or lock event moves Car Thing to a low-power time and date screen. Its physical backlight follows ambient light within a calibrated nonzero range so the clock remains legible.

Carthios restores the saved manual brightness, or resumes auto brightness, only after the Mac is both awake and unlocked. Inactivity never changes pages, there is no manual sleep button, and Car Thing controls cannot wake the display while the Mac is sleeping or locked. The setting is enabled by default and can be turned off at any time.

Maintenance

Updates and firmware

The Mac app updates through Sparkle with signed, notarized releases. When the Mac app recognizes an authorized Car Thing over USB, it checks both the bundled version and the complete dashboard/service payload fingerprint before choosing USB or Bluetooth for the session.

If either differs, Carthios shows Updating Carthios on the device and installs the matching payload automatically without a confirmation prompt. Keep the data cable connected until the normal dashboard returns. Installation is transactional and restores a working dashboard if a later service step fails; firmware/dashboard installation is not available over Bluetooth.

Help

Troubleshooting

Car Thing says the Mac is disconnected

Confirm Carthios is running. For USB, use a data-capable cable; a charging indicator does not prove the data path works. For Bluetooth, pair once in the Car Thing submenu. You can leave both transports available while Carthios verifies and selects USB.

Dictation says no speech or unavailable

Use USB, hold Home before speaking, and release only when finished. Confirm Speech Recognition permission. Accessibility is optional and affects insertion—not transcription.

Agenda is empty

Open the Calendar & Reminders submenu and check whether the status says Calendar Only, Reminders Only, Permission Needed, or Access Denied. For partial access, use the missing-permission button in that submenu.

Weather is unavailable

Confirm Location Services is enabled for Carthios, then reopen Weather or use its retry button. A recently successful forecast may remain available from RAM for up to six hours when location or the provider is temporarily unavailable.

Buses are missing

Some agencies require a separate free bus API key. Open Transit Settings and read the provider-specific message.

The app asks for removable-drive access

Install in Applications and eject the DMG. Do not keep launching the copy inside the mounted installer.

Bluetooth connects and immediately drops

If authenticated USB is active, Bluetooth stopping is expected because USB is primary. To test wireless fallback, unplug USB after the matching secure Bluetooth bridge has installed. If Bluetooth still drops, reconnect USB once for repair, then retry the handoff.

Updating Carthios was interrupted

Reconnect a data-capable USB cable and leave Car Thing attached while launching the Mac app again. Carthios rechecks the complete payload, repairs changed or missing files automatically, and returns to the normal dashboard when the transaction finishes.

Roadmap

Requested feature status

Request	Status	Notes
Calendar + Reminders Agenda	Shipped	Events, due reminders, completion, permission states, long-press preset 2, and immediate EventKit-driven updates.
Weather	Shipped	Current, hourly, and four-day conditions; hold preset 4 to open it, or optionally show current conditions on Clock.
Mac sleep and lock mirroring	Shipped	Optional ambient-aware low-power clock and exact brightness-state restoration over USB or Bluetooth.
Apple Music	Shipped	Switch directly from the Mac menu for songs and Radio with metadata, artwork, progress, playback, seeking, ten-step volume, shuffle, and repeat.
Layout & Controls	In progress	The first-party editor is implemented but remains gated until its complete physical 800×480, USB, and Bluetooth release pass.
YouTube Music	Blocked	Requires provider permission or a supported playback-session API before implementation can begin.
Bluetooth dictation	Investigating	Current microphone transport requires USB data; RFCOMM bandwidth, latency, and reliability remain unproven.
Bluetooth firmware updates	Investigating	Current updates require USB; any wireless design must first prove authenticated resumable transfer, rollback, and recovery.
On-device wake word and voice commands	Deferred	Work is paused unless an offline model can first meet latency, false-activation, memory, thermal, and privacy requirements.
Smarter local dictation	Partial	On-device recognition, punctuation, and optional Smart Cleanup ship; broader Whisper Flow-style rewriting is limited to supported Apple Intelligence APIs.
Lyrics and audiobook transcription	Deferred	Work is paused by product decision.
Declarative app catalog	Planned	A reviewed, signed data-and-assets-only extension model follows Layout & Controls; package code and remote code are out of scope.
Direct-download Carthios 3 purchase	In progress	The dormant policy boundary exists, but no paywall or activation ships until licensing, entitlement, migration, refund, and offline behavior are approved.
Spotify playback without another login	Shipped	Core controls use the signed-in Spotify Desktop app; account-scoped features still require optional Spotify authorization.
Privacy-first product diagnostics	Shipped	Optional, off by default, and limited to coarse allowlisted usage and reliability events. Dictated text/audio, music metadata/history, Agenda content, location, credentials, and device identifiers are excluded.