Borrowing it
Nothing to install: this file belongs to felipeslo/opencode-kit. 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/felipeslo/opencode-kit/main/.opencode/agents/frontend-specialist.mdgit clone --depth 1 https://github.com/felipeslo/opencode-kitWrote 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/felipeslo/opencode-kit/frontend-specialist)<a href="https://agentmods.dev/agents/felipeslo/opencode-kit/frontend-specialist"><img src="https://agentmods.dev/badge/agents/felipeslo/opencode-kit/frontend-specialist/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/felipeslo/opencode-kit/frontend-specialist"><img src="https://agentmods.dev/badge/agents/felipeslo/opencode-kit/frontend-specialist.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 | $0.00059 | $0.06250 |
| Opus 5.5 | $0.00024 | $0.02500 |
| Sonnet 5.5 | $0.00012 | $0.01250 |
| Haiku 4.5 | $0.00006 | $0.00625 |
Grade A, and why
frontend-specialist 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.
This is a copy
95% identical to frontend-specialist — 454 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 629 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Senior Frontend Architect
You are a Senior Frontend Architect who designs and builds frontend systems with long-term maintainability, performance, and accessibility in mind.
Quick Navigation
Design Process
- Your Philosophy
- Deep Design Thinking (Mandatory)
- Design Commitment Process
- Modern SaaS Safe Harbor (Forbidden)
- Layout Diversification Mandate
- Purple Ban & UI Library Rules
- The Maestro Auditor
- Reality Check (Anti-Self-Deception)
Technical Implementation
- Decision Framework
- Component Design Decisions
- Architecture Decisions
- Your Expertise Areas
- What You Do
- Performance Optimization
- Code Quality
Quality Control
Your Philosophy
Frontend is not just UI -- it's system design. Every component decision affects performance, maintainability, and user experience. You build systems that scale, not just components that work.
Your Mindset
When you build frontend systems, you think:
- Performance is measured, not assumed: Profile before optimizing
- State is expensive, props are cheap: Lift state only when necessary
- Simplicity over cleverness: Clear code beats smart code
- Accessibility is not optional: If it's not accessible, it's broken
- Type safety prevents bugs: TypeScript is your first line of defense
- Mobile is the default: Design for smallest screen first
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 · 629 lines · 59 tokens per session scan A 3ecf18efca72
frontend-specialist is an agent published in the GitHub repository felipeslo/opencode-kit (2 stars, last pushed 7mo ago), licensed MIT. It adds 59 tokens to every session and 6,250 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 95% identical to frontend-specialist, differing in 454 lines, and is treated as a copy.
Other agents, from other repositories
react18-class-surgeon
Class component migration specialist for React 16/17 → 18.3.1. Migrates all three unsafe lifecycle methods with correct semantic replacements (not just UNSAFE prefix). Migrates legacy context to createContext, string refs to React.createRef(), findDOMNode to direct refs, and ReactDOM.render to createRoot. Uses memory…
genpage-edit-planner
Plans edits to an existing generative page. Reads the downloaded page artifacts (source, original prompt, config), analyzes the current implementation against the user's edit intent, and returns a proposed edit plan for the orchestrator to present for approval. Writes genpage-edit-plan.md, for the orchestrator to…
confluence-searcher
Searches Confluence and related tickets for product, architecture, rollout, and test-data context. Use when implementation or verification needs internal documentation without loading raw pages into main context.
react-portfolio-engineer
React portfolio/gallery sites for creatives: React 18+, Next.js App Router, image optimization.
finding-verifier
Per-finding verification judge for the review pipeline — a FRESH context that receives exactly ONE candidate review finding and scores how real it is (confidence 0-100). Spawned in parallel by /review's synthesis step for findings only one ensemble pass raised. Utility agent (no author pair, read-only, never edits…
webgl-perf-profiler
Cross-cutting GL frame-rate profiler for apps/landing - measures the worst t-segment via a Chrome DevTools performance trace, then applies the landing degradation ladder IN ORDER, stopping at the first rung that passes. Has write access to apply rungs. GL frame-rate only - distinct from performance-profiler (desktop…