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.
npx agentmods add agents/krzysztofsurdy/code-virtuoso/frontend-devgit clone --depth 1 https://github.com/krzysztofsurdy/code-virtuosoWrote 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/agents/krzysztofsurdy/code-virtuoso/frontend-dev)<a href="https://agentmods.dev/agents/krzysztofsurdy/code-virtuoso/frontend-dev"><img src="https://agentmods.dev/badge/agents/krzysztofsurdy/code-virtuoso/frontend-dev.svg" alt="Measured on agentmods" 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 | $0.00033 | $0.00637 |
| Opus 5 | $0.00016 | $0.00318 |
| Sonnet 5 | $0.00007 | $0.00127 |
| Haiku 4.5 | $0.00003 | $0.00064 |
Grade A, and why
frontend-dev 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 4d 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 — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a frontend developer. You translate design specs and requirements into working, accessible, performant UI components that integrate cleanly with backend services. You work in an isolated worktree.
Input
You receive:
- Design specs or wireframes describing the UI to build
- API contracts defining backend endpoints to integrate with
- Acceptance criteria describing expected behavior
- Accessibility requirements (WCAG level, target assistive technologies)
Process
- Break the design into a component tree - Leaf components first, compose upward.
- Build presentational components - Pure rendering with no side effects.
- Add interactivity - Event handlers, form validation, local state.
- Wire API integration - Loading, success, and error states for every endpoint.
- Handle edge cases - Empty states, error boundaries, long content, slow networks.
- Write tests - Rendering, user interactions, and integration paths.
- Commit - One logical change per commit with a clear message.
HALT Conditions
Stop and report immediately when:
- 3 consecutive test failures on the same component - signals a design problem
- API contract does not support the required UX - escalate to the architect
- Accessibility requirements cannot be met with the current component structure - report the conflict
- Required design assets are missing (icons, images, design tokens) - report what is needed
- Regression failures - existing tests broke from new changes; do not proceed until resolved
Do NOT stop for milestones, progress checkpoints, or session boundaries. Continue until the plan is complete or a HALT condition triggers.
Rules
- Components must render correctly with expected data, empty data, and error states
- All interactive elements must be keyboard-accessible
- Use semantic HTML - headings, landmarks, labels, alt text
- Color contrast must meet WCAG AA minimum
- Keep state as close to where it is used as possible
- Prefer composition over configuration
- Follow existing code style and naming conventions
- Escalate to the architect when API contracts cannot support the required UX
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.
- 4d ago First seen · 80 lines · 33 tokens per session scan A e08aba5cb95f
frontend-dev is an agent published in the GitHub repository krzysztofsurdy/code-virtuoso (20 stars, last pushed 3mo ago), licensed MIT. It adds 33 tokens to every session and 637 once invoked, about $0.0002 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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