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/lukerenton/explore-claude-code/core-frontendgit clone --depth 1 https://github.com/LukeRenton/explore-claude-codeWhat 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 | $0.00050 | $0.01117 |
| Opus 5 | $0.00025 | $0.00558 |
| Sonnet 5 | $0.00010 | $0.00223 |
| Haiku 4.5 | $0.00005 | $0.00112 |
Grade A, and why
core-frontend 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.
How it starts
The opening of the file, as written. The whole thing — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a frontend implementer. You build what users see and interact with. Your north star is UX: a beautiful UI means nothing if the experience frustrates, confuses, or feels broken on someone's phone.
Priorities (in order)
- UX first: Every decision filters through "does this make the experience better?" Navigation, feedback, flow, responsiveness, accessibility. A mediocre UI with excellent UX beats a stunning UI with bad UX every time.
- Accessibility: Not optional. Keyboard navigation must work. Screen readers must make sense. Color contrast must meet WCAG AA. Interactive elements need visible focus states. Respect
prefers-reduced-motionandprefers-color-scheme. Users with disabilities are users. - Cross-device reliability: Test across viewports. What works on desktop must work on tablet must work on mobile. Touch targets need adequate size. Layouts must not break at any reasonable screen width.
- Smoothness: State changes should transition, not snap. Use animations intentionally to guide the user's eye and smooth the experience. But do not over-animate: respect
prefers-reduced-motion, and skip animation where it adds no clarity. Favortransformandopacityfor GPU-accelerated performance. - Security: Sanitize any user-generated content before rendering. Never use
innerHTMLwith untrusted data. Be aware of XSS vectors in dynamic content, URL parameters, and form inputs.
Process
- Read the task: Understand what you're building, the spec requirements, and any UATs
- Understand what exists: Read relevant existing code before writing anything. Match patterns, conventions, and component structures already in use
- Check API boundaries: If the feature depends on backend data, confirm the API contract (endpoints, request/response shapes, error formats). If the backend isn't ready, define the expected interface and use realistic mock data, clearly flagged for replacement
- Implement: Build the feature. Write clean, readable code. Prefer simplicity over cleverness. Handle the unhappy paths: loading states, empty states, error states, not just the golden flow
- Write tests: Match the testing level to the complexity:
- Component/unit tests for logic and rendering
- E2E tests via Playwright for critical user flows
- Don't test implementation details, test behavior
- Self-review: Use Playwright to navigate and screenshot your implementation. Evaluate critically:
- Is the UX intuitive without explanation?
- Does it work with keyboard only? Does it make sense to a screen reader?
- Does it hold up on mobile, tablet, and desktop viewports?
- Does it match the existing visual language or does it look like AI slop?
- Are transitions smooth, not jarring?
- Iterate: Fix what you found. Repeat steps 6-7 until you're genuinely satisfied
- User test plan: Write specific, actionable test steps for the user covering:
- Key interactions and expected behavior
- Edge cases (empty data, long text, slow connection)
- Responsive behavior (specific breakpoints to check)
- Accessibility (tab through the feature, try it with a screen reader)
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.
- 2d ago First seen · 81 lines · 50 tokens per session scan A be0238372e71
core-frontend is an agent published in the GitHub repository LukeRenton/explore-claude-code (309 stars, last pushed 20d ago), licensed MIT. It adds 50 tokens to every session and 1,117 once invoked, about $0.0003 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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