Borrowing it
Nothing to install: this file belongs to cardstack/boxel. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/cardstack/boxel/main/.claude/skills/choreo-regions/SKILL.mdgit clone --depth 1 https://github.com/cardstack/boxelWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/cardstack/boxel/choreo-regions)<a href="https://agentmods.dev/skills/cardstack/boxel/choreo-regions"><img src="https://agentmods.dev/badge/skills/cardstack/boxel/choreo-regions/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/cardstack/boxel/choreo-regions"><img src="https://agentmods.dev/badge/skills/cardstack/boxel/choreo-regions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00112 | $0.01418 |
| Opus 5.5 | $0.00045 | $0.00567 |
| Sonnet 5.5 | $0.00022 | $0.00284 |
| Haiku 4.5 | $0.00011 | $0.00142 |
Grade A, and why
choreo-regions scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 111 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Regions and far matching
A region is a scene, not a provider
<Choreo> belongs around the machine it choreographs — the workspace, the
modal, the panel, the list. Never wrap body: one root region makes
every id/role in the app one changeset. The app’s route crossing uses a deliberate <Choreo @route> boundary around
the outlet (magic-move-navigation), not an unscoped region around the body.
Discovery is nearest-wins: a {{motion id= role=}} registers with the
nearest <Choreo> ancestor, and a region's timeline collection skips any
child region. Two stacked <Choreo>s are two scenes, each with its own
snapshot, changeset, orphan layer, and run. Queries do not leak
(shell.kept 'card' never sees the panel's cards) and there is no shared
clock — the shell's Sequence does not wait for the panel's Move.
Where the boundary goes:
| Situation | Region(s) |
|---|---|
| Sidebar + main + drawer sharing one sequence | one Choreo |
| A list with its own enter/leave inside a moving panel | panel outer, list inner |
| A modal with its own orphans over a page that also moves | page outer, modal inner |
| "I need the trash can's box from the list" | not a region question — a {{beacon}} |
Put id/role only on nodes that scene should see. An inner region
measures its own pass correctly even while an outer region is translating
the box it lives in — that is the intended answer to "a card controls its
own contents while a layout above moves it".
Far matching — one identity, two regions
Without it, an element leaving region A and appearing in region B is a death here and an unrelated birth there. With it, the two halves are paired and the move reads as one continuous flight — the Boxel case: a card moving between panels/stacks that are separate scenes on purpose.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 111 lines · 112 tokens per session scan A fff69403b678
choreo-regions is a skill published in the GitHub repository cardstack/boxel (27 stars, last pushed today), licensed MIT. It adds 112 tokens to every session and 1,418 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-21.
Other skills, from other repositories
webgl-holographic-foil
A self-contained WebGL2 hero: thin-film interference over a crushed-foil surface whose palette shifts with the viewing angle; move the cursor to tilt the film.
html-ppt-hermes-cyber-terminal
OpenDesign + BYOK: choosing and wiring your own model, hands-on — cost, quality, and the routing decision. Built as a decision-grade AI literacy deck for engineers, IT, applied-AI teams.
html-ppt-taste-brutalist
16:9 HTML deck in tactical-telemetry / CRT-terminal taste. Deactivated-CRT charcoal slides, white-phosphor monospace, hazard-red accent, scanline overlay, ASCII syntax, density over decoration. Distilled from Leonxlnx/taste-skill brutalist-skill (Tactical Telemetry mode).
visual-ralph
Visual Ralph orchestration for frontend UI from generated references, static references, or live URL targets, using $ultragoal with built-in visual verdict and pixel-diff evidence until the implementation matches and leaves a reproducible design system.
glance-canonical-layouts
Use this skill to create home screen widgets using Jetpack Glance Canonical Layouts from the Android Platform Samples project, or when asked to implement standard widget layout patterns (including Check List, Image Grid, Snap Scrolling, and Standard Toolbar).
accessibility
Consolidated accessibility skill entrypoint for WCAG 2.2, ARIA Authoring Practices, cognitive accessibility, Section 508, EN 301 549, design intent verification, and the Accessibility Planner workflow.