Caementum
“concrete”
rawheavyplain
Heavy concrete slabs stacked at the edges, with one small red square.
Grey concrete blocks with hard shadows stacked at the left and right edges, and one small red square. Held still, as it is while you read.
The plate
Raw concrete in flat slabs. By night the page is a mid grey hall and the blocks at its edges cast hard dark shadows. By day the same blocks are pale board formed concrete with the marks of the planks still in them. While Claude works, a slab slides one step along the grid and stops, slowly, like a heavy door. When the answer is ready nothing moves.
While Claude works
The spinner takes one of these words in place of “Working”. When the app names the step it is on, that name stays.
- Pouring
- Setting
- Curing
- Casting
- Bracing
- Stacking
After a turn of 20 seconds or more, Caementum plays a soft chime under a second and a half long.
With /tessera music, a quiet loop of its own plays while Claude works and stops when the answer is ready. It is off until you ask for it.
Palette
Light
- Page
#ece9e3 - Card
#f0eee9 - Panel
#f4f3ef - Text
#2a2826 - Secondary
#3f3d39 - Muted
#4f4d48
Dark
- Page
#2c2a27 - Card
#312f2c - Panel
#363431 - Menu
#3b3936 - Text
#dddad5 - Secondary
#c1beb8 - Muted
#adaaa4
Roles
- Accent
#c8473c - Danger
#b04476 - Success
#4f9a6a - Warning
#c49530 - Pro
#7d7aa8
Measured
Standard contrast. Body text is held at 9:1 to 14:1. Here it measures 12.1:1 in light and 10.3:1 in dark. Calm accents.
| Reading | Light | Dark |
|---|---|---|
| Body text on the page | 12.1:1 | 10.3:1 |
| Muted text on the page | 7:1 | 6.2:1 |
| Page lightness | 93% | 29% |
| Glass | 66%, 18 pt blur | 66%, 18 pt blur |
Contrast is the WCAG ratio. Muted text is held at 4.5:1 or better. Lightness is OKLCH, where 0% is black and 100% is white.
Install
Hang Caementum
-
1 In the desktop app
Click + next to the prompt box and choose Plugins. Add the marketplace btahir/tessera, then add the tessera plugin.
btahir/tessera -
2 In a terminal session
Paste this at the prompt.
/plugin install tessera --marketplace btahir/tessera -
3 Ask Claude
Send this sentence in any session.
Install the tessera plugin from the btahir/tessera marketplace on GitHub.
Then
The tessera plugin holds all twenty-five plates.
Type /tessera caementum to hang Caementum.
/tessera still stops the motion. Sound has three levels: /tessera quiet is silence,
/tessera sound is a chime after long turns (the default), and /tessera music adds the room's own
quiet loop while Claude works. Your choices are kept across sessions.
Only Caementum
Each plate also installs by its own name, and its commands use that name, such as /caementum still or /caementum music.
/plugin install caementum --marketplace btahir/tessera Where it shows
Themes appear in the Claude Code desktop and mobile apps. The terminal keeps its own colors. The chime plays on macOS only.