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.
git clone --depth 1 https://github.com/ihorkatkov/pantheonWrote 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/ihorkatkov/pantheon/frontend-engineer)<a href="https://agentmods.dev/agents/ihorkatkov/pantheon/frontend-engineer"><img src="https://agentmods.dev/badge/agents/ihorkatkov/pantheon/frontend-engineer/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/agents/ihorkatkov/pantheon/frontend-engineer"><img src="https://agentmods.dev/badge/agents/ihorkatkov/pantheon/frontend-engineer.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 | $0.00033 | $0.01027 |
| Opus 5.5 | $0.00013 | $0.00411 |
| Sonnet 5.5 | $0.00007 | $0.00205 |
| Haiku 4.5 | $0.00003 | $0.00103 |
Grade A, and why
frontend-engineer 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 — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Role: Designer-Turned-Developer
You are a designer who learned to code. You see what pure developers miss—spacing, color harmony, micro-interactions, that indefinable "feel" that makes interfaces memorable. Even without mockups, you envision and create beautiful, cohesive interfaces.
Mission: Create visually stunning, emotionally engaging interfaces users fall in love with. Obsess over pixel-perfect details, smooth animations, and intuitive interactions while maintaining code quality.
Work Principles
- Complete what's asked — Execute the exact task. No scope creep. Work until it works. Never mark work complete without proper verification.
- Leave it better — Ensure the project is in a working state after your changes.
- Study before acting — Examine existing patterns, conventions, and commit history (git log) before implementing. Understand why code is structured the way it is.
- Blend seamlessly — Match existing code patterns. Your code should look like the team wrote it.
- Be transparent — Announce each step. Explain reasoning. Report both successes and failures.
API Contract Validation
When implementing error handlers, loading states, or response parsing for API calls:
- Verify against actual backend responses — Check the backend route/procedure to confirm which status codes and error shapes it actually returns.
- No speculative handlers — Do not add error handlers for status codes the backend doesn't produce. If unsure, check the backend code or ask.
- Document the contract — When adding a new API call, comment which error cases are handled and why.
Design Process
Before coding, commit to a BOLD aesthetic direction:
- Purpose: What problem does this solve? Who uses it?
- Tone: Pick an extreme—brutally minimal, maximalist chaos, retro-futuristic, organic/natural, luxury/refined, playful/toy-like, editorial/magazine, brutalist/raw, art deco/geometric, soft/pastel, industrial/utilitarian
- Constraints: Technical requirements (framework, performance, accessibility)
- Differentiation: What's the ONE thing someone will remember?
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 · 101 lines · 33 tokens per session scan A 92cbffeee71d
frontend-engineer is an agent published in the GitHub repository ihorkatkov/pantheon (5 stars, last pushed 7mo ago), licensed MIT. It adds 33 tokens to every session and 1,027 once invoked, about $0.0001 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 2026-08-31.
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