theme

A project-specific guide for applying a brand’s colors, typography, icons, and interface rules in a Mantle web project.

In plain words
What is it for?
Use it to inspect the project’s theme files, update shared design tokens and components, add new web sections, and maintain site icons.
Why use it?
It helps visual changes fit the project’s existing theme and keeps shared design settings consistent across the site and its supporting interfaces.

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/aotter/mantle/theme
Any agent
npx skills add aotter/mantle --skill theme
Clone the repo
git clone --depth 1 https://github.com/aotter/mantle

Made for: Claude Code, Codex.

Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 723 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 $0.00022 $0.00723
Opus 5 $0.00011 $0.00362
Sonnet 5 $0.00004 $0.00145
Haiku 4.5 $0.00002 $0.00072

Measured 2d ago against content hash f36cb533d735, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

theme 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 2d 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.

skills/theme/SKILL.md · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mantle Theme

Theme work is project-owned source editing. Starters may ship UI files, tokens, or recipes, but the skill contract is Core-owned.

First Read

  1. .mantle/handoff.md and .mantle/recipes/ if present.
  2. styles/, components/, src/web/, src/theme*, and UI-library config if present.
  3. A vendored UI palette's manifest and license, if present.
  4. manifests/site.yaml to understand which content shape drives the public UI.

Ownership

  • styles/globals.css is the token contract. Start a whole-site reskin with its :root and .dark values; runtime components inherit those variables.
  • components/ is the runtime-facing component surface when present. src/web/ is project-owned composition; put new sections there.
  • public/site-icon.svg and public/site-icon.png are one site identity. Keep both listed in src/mantle/config.ts > siteDefaults.icons: PNG first as the 64x64 compatibility rendition, then SVG as the editable any size source. The same list drives browser favicons, Admin chrome, and MCP serverInfo.icons; do not edit generated files under public/_mantle/.
  • If the project includes a vendored UI reference palette, treat it as offline source material and provenance, not runtime source. Copy only a needed primitive or block into the project's runtime directories, or fork/wrap it under src/web/sections/; do not import the palette from Worker or runtime code.

Work

  • Use existing tokens, CSS, components, and installed dependencies first.
  • When replacing the site mark, regenerate PNG from the same SVG artwork so every surface presents the same identity. Check it at the Admin's 28px slot in both light and dark themes; a single high-contrast rendition is preferred over theme-specific variants unless the artwork genuinely needs both.
  • For a standard hero image, set the section's image: { src, alt }; use showImage: false for text-only hero/content blocks. Put non-image media in a project-owned section.
  • Keep accessibility basics: semantic HTML, focus states, contrast, and keyboard reachability. Against a non-default background, check --foreground-muted and --primary, not only --foreground; keep normal text at 4.5:1 or better.
  • Do not require registry access for a project that already vendors UI source.
  • Add UI dependencies only when existing source cannot cover the requested change.

Read the full file on GitHub · 71 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. 2d ago First seen · 71 lines · 22 tokens per session scan A f36cb533d735

Subscribe to this mod's changes

theme is a skill published in the GitHub repository aotter/mantle (4 stars, last pushed 7d ago), licensed Apache-2.0. It adds 22 tokens to every session and 723 once invoked, about $0.0001 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 2026-08-31.

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