Chromecast Control — cast / ca

Discover and control Google Cast devices on your Wi-Fi — Chromecast, Google TV, Nest displays, and cast-enabled TVs. Launch a video, cast a URL or a saved item, control playback, and share photos/videos straight off the SD card.

Own devices only.

  1. How it works
  2. Usage
  3. Interactive mode
  4. Saved content — /apps/cast/media.csv
  5. Share local files — /apps/cast/share/
  6. Files
  7. Honest limits

How it works

A Cast device exposes two control channels; cast uses both:

  • DIAL (:8008, plain HTTP) — launches apps like YouTube. Light, no TLS. This is the “rickroll” path.
  • Cast v2 (:8009, TLS + protobuf) — real playback: load a media URL, play/pause/stop, volume, and now-playing status.

For local files, a Cast device can only fetch from a URL — so the T-Deck briefly becomes a small HTTP server and hands the device a http://<t-deck-ip>:8123/<file> URL to pull (with HTTP Range support so video can seek).

Usage

You must be on the same Wi-Fi as the TV (cw).

CMD> cw MyWiFi password     # join the LAN
CMD> ca                     # scan (mDNS) + interactive picker
CMD> ca 192.168.1.42        # jump straight to a device's menu
CMD> ca rickroll 192.168.1.42
CMD> ca saved 192.168.1.42 "Big Buck Bunny"
CMD> ca share 192.168.1.42 photo.jpg
CMD> ca launch 192.168.1.42 https://example.com/clip.mp4
CMD> ca vol 192.168.1.42 30
CMD> ca stop 192.168.1.42

Interactive mode

ca (no target) scans via mDNS, then opens a device picker → action menu. Everything is drivable by trackball or keyboard:

  • Trackball ↑/↓ or w / s — move the selection
  • Click or Enter — activate
  • 1–9 — quick-pick a row in one press
  • u — rescan (device picker) · q — back one level

Action menu: Rickroll · Saved content · Share photo/video · Play/Pause/Stop · Volume ± · Mute · Now playing. Destructive actions (Rickroll, Stop) confirm first.

Saved content — /apps/cast/media.csv

Self-seeds on first run. One entry per line, name,target:

# name,url-or-youtube-id
Rickroll,dQw4w9WgXcQ
Big Buck Bunny,https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4
My Stream,http://192.168.1.10:8080/stream.m3u8

An http(s) target plays via Cast v2; a bare id launches YouTube via DIAL (auto-detected, tagged [url] / [yt]).

Share local files — /apps/cast/share/

Drop images (.jpg .png .gif .webp .bmp) and videos (.mp4 .webm .m4v) into /apps/cast/share, then “Share photo/video (SD)…” (or ca share <ip> <file>). The T-Deck serves the file and the TV fetches it. A live requests / served KB counter shows progress; [q] stops.

Files

Path Contents
/apps/cast/devices.csv discovered Cast devices (ip,name,model)
/apps/cast/media.csv saved content (name,url-or-youtube-id)
/apps/cast/share/ local photos/videos to cast

Honest limits

  • Cast v2 uses TLS — the ~30–40 KB handshake DRAM cost. If :8009 fails, the DIAL path still works.
  • Sharing a video keeps the T-Deck busy as the file server until you press [q] (images fetch once).
  • No transcoding — the TV must natively support the codec (mp4/H.264, webm/VP8-9 play; mkv/avi/HEVC generally won’t).
  • DIAL YouTube launching works today but Google has narrowed DIAL over the years; Cast v2 is the durable path.
  • Own networks / own devices only.