Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add AppsVortex/arness/plugin install arn-sparkWrote 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/appsvortex/arness/arn-spark-visual-strategy)<a href="https://agentmods.dev/skills/appsvortex/arness/arn-spark-visual-strategy"><img src="https://agentmods.dev/badge/skills/appsvortex/arness/arn-spark-visual-strategy/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/appsvortex/arness/arn-spark-visual-strategy"><img src="https://agentmods.dev/badge/skills/appsvortex/arness/arn-spark-visual-strategy.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 | $0.00124 | $0.06110 |
| Opus 5.5 | $0.00050 | $0.02444 |
| Sonnet 5.5 | $0.00025 | $0.01222 |
| Haiku 4.5 | $0.00012 | $0.00611 |
Grade A, and why
arn-spark-visual-strategy 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 today.
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 — 448 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Arness Visual Strategy
Set up automated visual regression testing so that during feature development, each implemented screen can be compared pixel-by-pixel against the approved prototype screenshots. The prototype screenshots serve as baseline images — the "gold standard" of what the UI should look like. As features are built, capture scripts take screenshots of the development build and comparison scripts diff them against these baselines, catching layout breaks, color mismatches, and misplaced elements before they reach the user.
This is a conversational skill that runs in normal conversation (NOT plan mode). It uses the arn-spark-visual-test-engineer agent for proof-of-concept validation and script generation.
The primary artifacts are:
- Capture script — takes screenshots of the development build (NOT the prototype)
- Comparison script — diffs development screenshots against prototype baselines
- Baseline images — copied from prototype screenshots, used as the reference standard
- CLAUDE.md configuration — integrates visual testing into the Arness execution pipeline so that
/arn-code-execute-planand/arn-code-execute-taskautomatically validate UI changes
The core problem this solves: during feature development, visual regressions (button on the wrong side, layout breaks, color mismatches) go undetected until the user manually inspects the application. This skill sets up the tooling so that every UI task automatically compares the development build against the prototype.
Prerequisites
Read the project's CLAUDE.md for a ## Arness section. If no ## Arness section exists or Arness Spark fields are missing, inform the user: "Arness Spark is not configured for this project yet. Run /arn-brainstorming to get started — it will set everything up automatically." Do not proceed without it.
Extract:
- Vision directory (default:
.arness/vision) - Prototypes directory (default:
.arness/prototypes) - Spikes directory (default:
.arness/spikes) -- for mini-spike workspaces - Git / Platform
What ships with it
5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- today First seen · 448 lines · 124 tokens per session scan A 210445781028
arn-spark-visual-strategy is a skill published in the GitHub repository AppsVortex/arness (33 stars, last pushed today), licensed MIT. It adds 124 tokens to every session and 6,110 once invoked, about $0.0005 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 2026-10-25.
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