Borrowing it
Nothing to install: this file belongs to gridaco/nothing. 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/gridaco/nothing/main/.agents/skills/dev-render-htmlcss-feature/SKILL.mdgit clone --depth 1 https://github.com/gridaco/nothingWrote 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/gridaco/nothing/dev-render-htmlcss-feature)<a href="https://agentmods.dev/skills/gridaco/nothing/dev-render-htmlcss-feature"><img src="https://agentmods.dev/badge/skills/gridaco/nothing/dev-render-htmlcss-feature/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/gridaco/nothing/dev-render-htmlcss-feature"><img src="https://agentmods.dev/badge/skills/gridaco/nothing/dev-render-htmlcss-feature.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Prompt Injection · line 279 Large whitespace padding was detected (a block of blank lines or a long run of spaces). This can push injected instructions below or to the right of the visible area so a human reviewer never sees them while the agent still reads them. Manual review of the hidden content is recommended.Fix: Remove the large whitespace padding (blank-line blocks or long space runs) and review any content hidden below or to the right of it. Keep skill files compact and reviewable so no instructions can be
- medium Agent Snooping · line 302 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
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 | $0.00044 | $0.03531 |
| Opus 5.5 | $0.00018 | $0.01412 |
| Sonnet 5.5 | $0.00009 | $0.00706 |
| Haiku 4.5 | $0.00004 | $0.00353 |
Grade A, and why
dev-render-htmlcss-feature 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 2mo 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 — 325 lines — stays where its author put it; the contents beside it link to each section on GitHub.
grida-htmlcss — feature loop
What this is. A heavy, manually-invoked loop for driving a single
CSS feature forward in the grida htmlcss renderer. Do not auto-trigger;
load only when the user explicitly runs it. The loop is a conductor
over /research, /fixtures, and /render-reftest — those auto-trigger
on their own for narrower work.
Sibling skill. For features in the SVG path
(crates/htmlcss/src/svg/, resvg-test-suite corpus,
multi-oracle scoring against expected.png + baked Chrome PNG), use
dev-render-htmlcss-svg-feature
instead. Same five-phase shape, different tooling.
Lifecycle. Expect this skill to grow as new divergence patterns surface. It will likely go stale in parts once htmlcss hits Chromium-parity on L0/L1; treat the phase structure as durable and the property-specific callouts as advisory.
The five phases
┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐
│ 1. AUDIT │→ │2. GROUND │→ │3. FIXTURE│→ │ 4. IMPL │→ │5. VERIFY │
└──────────┘ └──────────┘ └──────────┘ └──────────┘ └──────────┘
│ │
└───── ← ─── loop ← ─── score < floor ← ─── diff ← ───────┘
Each phase has a question it answers, a deliverable, and an exit criterion. Don't skip forward; don't linger past the exit criterion. The loop closes at verify — if the score is below the gate, return to phase 3 or 4 with a specific hypothesis, not a vibe.
1. Audit — "what's the actual state of this feature?"
Question. Where is the feature on the grida side today? What renders wrong, what doesn't render at all, what renders coincidentally-correctly but by the wrong path?
Actions.
- Scan
crates/htmlcss/src/for the property name in stylo enum mapping, paint emit, layout feed. A property can be parsed-but-dropped, emitted-but-wrong, or unhandled — each has a different fix shape. - Enumerate existing fixtures that touch the feature
(
fixtures/test-html/L0/). Run them underL0.coverageand record current similarity per fixture. This is the before-number. - Check
docs/wg/feat-2d/htmlcss.mdand any related design notes for a prior decision or deliberate gap. - List sibling properties likely to break the same way (e.g.
border-radius%-values impliedborder-image-slice%-values).
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.
- 2mo ago First seen · 325 lines · 44 tokens per session scan A a516fa5960d7
dev-render-htmlcss-feature is a skill published in the GitHub repository gridaco/nothing (54 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 44 tokens to every session and 3,531 once invoked, about $0.0002 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 2026-08-30.
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