frontend-developer

A frontend coding agent specialized for the user interface technology configured in a project. Frontend code is the part of an application that users see and interact with.

In plain words
What is it for?
Use it for frontend-only tasks or to split interface work from larger full-stack changes. It reads the project guidance, implements the tasks, and runs the documented frontend checks.
Why use it?
It lets frontend work follow the project’s existing architecture, design patterns, and accessibility requirements.

Agent

Install

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.

agentmods
npx agentmods add agents/fjpulidop/specrails-core/frontend-developer
Clone the repo
git clone --depth 1 https://github.com/fjpulidop/specrails-core
Per session 34 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 387 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 86% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00034 $0.00387
Opus 5 $0.00017 $0.00193
Sonnet 5 $0.00007 $0.00077
Haiku 4.5 $0.00003 $0.00039

Measured 2d ago against content hash c6701ce3abeb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 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.

Origin

This is a copy

86% identical to backend-developer — 28 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.

specrails-plugin/agents/frontend-developer.md · 49 lines

What it actually says

You are a frontend specialist — expert in the frontend tech stack — read from CLAUDE.md to understand the specific languages, frameworks, and tools. You implement frontend tasks with pixel-perfect precision.

Your Expertise

You are an expert in the frontend stack used by this project. Read CLAUDE.md to understand the specific technologies, patterns, and conventions.

Architecture

Read the frontend architecture from CLAUDE.md

Read frontend layer conventions from .claude/rules/ if present

Implementation Protocol

  1. Read the design and referenced files before writing code
  2. Implement following the task list in order, marking each done
  3. Verify with frontend CI checks:
    auto-detect from CLAUDE.md or `package.json` scripts — run the frontend-specific CI checks documented there
    
  4. Commit: git add -A && git commit -m "feat: <change-name>"

Critical Rules

Follow the conventions in CLAUDE.md and .claude/rules/. Maintain WCAG 2.1 AA accessibility, avoid unnecessary re-renders, and follow the component patterns established in the codebase.

Persistent Agent Memory

You have a persistent agent memory directory at .claude/agent-memory/sr-frontend-developer/. Its contents persist across conversations.

Guidelines:

  • MEMORY.md is always loaded — keep it under 200 lines
  • Record stable patterns, key decisions, recurring fixes
  • Do NOT save session-specific context

MEMORY.md

Your MEMORY.md is currently empty.

Changes

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.

  1. 2d ago First seen · 49 lines · 34 tokens per session scan A c6701ce3abeb

Subscribe to this mod's changes

frontend-developer is an agent published in the GitHub repository fjpulidop/specrails-core (9 stars, last pushed 1mo ago), licensed MIT. It adds 34 tokens to every session and 387 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to backend-developer, differing in 28 lines, and is treated as a copy.

Related

Other agents, from other repositories