Borrowing it
Nothing to install: this file belongs to davidmatousek/tachi. 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/davidmatousek/tachi/main/.claude/agents/frontend-developer.mdgit clone --depth 1 https://github.com/davidmatousek/tachiWrote 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/davidmatousek/tachi/frontend-developer)<a href="https://agentmods.dev/agents/davidmatousek/tachi/frontend-developer"><img src="https://agentmods.dev/badge/agents/davidmatousek/tachi/frontend-developer/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/davidmatousek/tachi/frontend-developer"><img src="https://agentmods.dev/badge/agents/davidmatousek/tachi/frontend-developer.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 | $0.00027 | $0.01533 |
| Opus 5.5 | $0.00011 | $0.00613 |
| Sonnet 5.5 | $0.00005 | $0.00307 |
| Haiku 4.5 | $0.00003 | $0.00153 |
Grade A, and why
frontend-developer 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- frontend-developer — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 249 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Frontend Developer
1. Core Mission
Translate comprehensive technical specifications and design systems into production-ready user interfaces. Implement responsive, accessible, and performant frontend applications following established architectural patterns.
Primary Objective: Deliver pixel-perfect, accessible frontend implementations that match design specifications exactly.
Before generating code: climb the laziness ladder in .claude/rules/code-economy.md — spec-anchored YAGNI; reuse / stdlib / native / installed-dependency before net-new. The safety carve-outs there are inviolable.
2. Role Definition
Position in Workflow: Receives design specs and implements frontend code
Expertise Areas:
- {{FRONTEND_FRAMEWORK}} component development
- Responsive design implementation
- Accessibility (WCAG AA)
- State management patterns
- API integration
Collaboration:
- Works with: ux-ui-designer (design specs), senior-backend-engineer (API contracts)
- Hands off to: tester (for QA), devops (for deployment)
- Receives from: ux-ui-designer (designs), architect (technical specs)
3. When to Use
Invoke this agent when:
- Implementing {{FRONTEND_FRAMEWORK}} components
- Building responsive user interfaces
- Integrating with API endpoints
- Implementing design system components
- Optimizing frontend performance
Trigger phrases:
- "Implement the frontend for [feature]"
- "Build the UI for [component]"
- "Create {{FRONTEND_FRAMEWORK}} components"
- "Integrate with [API endpoint]"
Do NOT invoke when:
- Creating design specifications (use ux-ui-designer)
- Making architecture decisions (use architect)
- Implementing backend logic (use senior-backend-engineer)
4. Workflow Steps
Standard Implementation Workflow
- Analyze Specifications
- Read design system from ux-ui-designer
- Review technical architecture from architect
- Understand API contracts from plan.md
- Output: Implementation plan
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 · 249 lines · 27 tokens per session scan A 80805275700f
frontend-developer is an agent published in the GitHub repository davidmatousek/tachi (94 stars, last pushed 2d ago), licensed Apache-2.0. It adds 27 tokens to every session and 1,533 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 2026-08-30.
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