dev-render-htmlcss-svg-feature

A manual five-step process for adding or studying one feature in Grida's SVG renderer, which draws scalable vector graphics in a browser-like rendering system.

In plain words
What is it for?
Use it for owner-directed SVG renderer work involving audits, fixtures, implementation, and verification against the resvg test suite or Chromium-rendered references.
Why use it?
It provides a fixed path for checking the existing code, preparing test cases, implementing a change, and comparing results with reference images.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/gridaco/nothing/dev-render-htmlcss-svg-feature
Any agent
npx skills add gridaco/nothing --skill dev-render-htmlcss-svg-feature
Clone the repo
git clone --depth 1 https://github.com/gridaco/nothing

Made for: Claude Code, Codex.

Per session 94 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,636 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00094 $0.05636
Opus 5 $0.00047 $0.02818
Sonnet 5 $0.00019 $0.01127
Haiku 4.5 $0.00009 $0.00564

Measured yesterday against content hash a250bb643164, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dev-render-htmlcss-svg-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 yesterday.

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.

.agents/skills/dev-render-htmlcss-svg-feature/SKILL.md · 512 lines

How it starts

The opening of the file, as written. The whole thing — 512 lines — stays where its author put it; the contents beside it link to each section on GitHub.

grida-htmlcss::svg — feature loop

Status (2026-07-24): the target module is a frozen donor. Per D-N, the SVG engine of record, no new behavior lands in htmlcss::svg; SVG capability evolves as rungs on the engine of record (websem → rframe → n0), Chromium-baked under fixtures/web-first/. Use this loop only for owner-directed wire-back or donor study — not for new feature work.

What this is. A heavy, manually-invoked loop for driving a single SVG feature forward in crates/htmlcss/src/svg/. Do not auto-trigger; load only when the user explicitly runs it.

Sister skill. dev-render-htmlcss-feature covers the HTML/CSS path (different code surface, different fixture suite, single oracle). This SKILL covers the SVG path: same five-phase shape, but different corpus and different scoring policy.

Aspect HTML/CSS sister skill This (SVG) skill
Renderer module crates/htmlcss/src/ (excl. svg/) crates/htmlcss/src/svg/
Corpus fixtures/test-html/L0/ (we author) fixtures/local/resvg-test-suite/ (vendored, 1679 fixtures)
Oracle Playwright Chromium (refbrowser, on-the-fly) expected.png (suite author) + baked Chrome PNG
Scoring Single oracle, gate=L0.exact floor 1.0 Multi-oracle: consensus / disputed / UB; gate = consensus pass-rate
Tooling cargo run -p grida_wpt -- render --suite … cargo run -p grida_dev -- reftest <run|bake|inspect|summary>

Why multi-oracle (read this before phase 1)

The resvg-test-suite ships one expected.png per fixture — but that PNG is the suite author's read of the spec, not a browser oracle. For ~12% of fixtures Chrome diverges from expected.png (disputed) and ~4% have no defined behavior at all (UB). The harness ingests the suite's results.csv (a 9-renderer status matrix) to classify each fixture:

Read the full file on GitHub · 512 lines

Changes

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.

  1. yesterday First seen · 512 lines · 94 tokens per session scan A a250bb643164

Subscribe to this mod's changes

dev-render-htmlcss-svg-feature is a skill published in the GitHub repository gridaco/nothing (43 stars, last pushed yesterday), licensed Apache-2.0. It adds 94 tokens to every session and 5,636 once invoked, about $0.0005 per session on Opus 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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