claude-devtools is a visual debugging application that reads Claude Code's locally saved logs and session transcripts and presents their hidden details. Developers use it to inspect tool inputs and outputs, file activity, token usage, subagents, context consumption, and team coordination. The catalogue entries add commands, hooks, agents, instructions, and settings for the tool.
Borrowing it
Nothing to install: this file belongs to matt1398/claude-devtools. 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/matt1398/claude-devtools/main/.claude/commands/devtools/design-system.mdgit clone --depth 1 https://github.com/matt1398/claude-devtoolsWrote 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/commands/matt1398/claude-devtools/design-system)<a href="https://agentmods.dev/commands/matt1398/claude-devtools/design-system"><img src="https://agentmods.dev/badge/commands/matt1398/claude-devtools/design-system/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/commands/matt1398/claude-devtools/design-system"><img src="https://agentmods.dev/badge/commands/matt1398/claude-devtools/design-system.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 | $0.00058 | $0.03802 |
| Opus 5.5 | $0.00023 | $0.01521 |
| Sonnet 5.5 | $0.00012 | $0.00760 |
| Haiku 4.5 | $0.00006 | $0.00380 |
Grade A, and why
claude-devtools:design-system 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 1mo 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 — 357 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Design System & Visual Language
How the theming, color palette, component patterns, and styling conventions work.
Theme Architecture
Two themes (dark/light) driven by CSS custom properties in src/renderer/index.css.
Toggled via useTheme() hook which adds/removes light class on document.documentElement.
Flash prevention: a script in index.html applies the cached theme before React loads.
Theme Hook
// src/renderer/hooks/useTheme.ts
const { theme, resolvedTheme, isDark, isLight } = useTheme();
// theme: 'dark' | 'light' | 'system'
// resolvedTheme: 'dark' | 'light' (after system resolution)
Styling Convention
Colors: Always via CSS variables (theme-aware). Use inline style or Tailwind classes mapped to variables.
Layout/spacing: Tailwind utility classes.
Icons: lucide-react with size-* Tailwind classes.
// Preferred: inline style for theme-aware colors, Tailwind for layout
<div className="flex items-center gap-2 rounded-md px-3 py-2"
style={{ backgroundColor: 'var(--color-surface-raised)', color: 'var(--color-text)' }}>
<Bot className="size-4 shrink-0" style={{ color: COLOR_TEXT_SECONDARY }} />
</div>
// Also valid: Tailwind classes that reference CSS variables
<div className="bg-surface text-text border-border">
<div className="bg-surface-raised text-text-secondary">
TypeScript Constants
src/renderer/constants/cssVariables.ts centralizes CSS variable strings:
import { COLOR_TEXT_MUTED, CARD_BG, CARD_BORDER_STYLE } from '@renderer/constants/cssVariables';
<span style={{ color: COLOR_TEXT_MUTED }}>Muted text</span>
<div style={{ backgroundColor: CARD_BG, border: CARD_BORDER_STYLE }}>Card</div>
Constants cover: text colors, surfaces, borders, code blocks, diff, cards, tags, prose.
CSS Variable Reference
All defined in src/renderer/index.css under :root (dark) and :root.light.
Surfaces
| Variable | Dark | Light | Usage |
|---|---|---|---|
--color-surface |
#141416 |
#f9f9f7 |
Main background |
--color-surface-raised |
#27272a |
#f0efed |
Elevated surfaces |
--color-surface-overlay |
#27272a |
#e8e7e4 |
Overlays/modals |
--color-surface-sidebar |
#0f0f11 |
#f1f0ee |
Sidebar background |
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.
- 1mo ago First seen · 357 lines · 58 tokens per session scan A b00ae0259fa3
claude-devtools:design-system is a command published in the GitHub repository matt1398/claude-devtools (3,994 stars, last pushed 1mo ago), licensed MIT. It adds 58 tokens to every session and 3,802 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.
Other commands, from other repositories
color-palette
Run the full colour workflow — tonal scales, semantic mapping, contrast checks, dark mode, and chart colours — and output a documented palette.
design-screen
Design a complete screen layout from a description or requirements.
responsive-audit
Audit a design's responsive behaviour across breakpoints — layout, touch targets, and content reflow.
type-system
Build a typography system end to end — scale, weights, line heights, measure, and responsive behaviour.
design-tokens
Définition Design Tokens.
atelier
Grupo: Diseño y Atelier En una frase: Design intelligence Impeccable + DT — craft, audit, anti-slop, 23+ commands. Cuándo: Landing, dashboard, mockup, craft UI, critique, polish, design system. Quién: Cualquier operador del repo.