Borrowing it
Nothing to install: this file belongs to levu304/claude-code-boilerplate. 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/levu304/claude-code-boilerplate/main/.claude/agents/fullstack-developer.mdgit clone --depth 1 https://github.com/levu304/claude-code-boilerplateWrote 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/levu304/claude-code-boilerplate/fullstack-developer)<a href="https://agentmods.dev/agents/levu304/claude-code-boilerplate/fullstack-developer"><img src="https://agentmods.dev/badge/agents/levu304/claude-code-boilerplate/fullstack-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/levu304/claude-code-boilerplate/fullstack-developer"><img src="https://agentmods.dev/badge/agents/levu304/claude-code-boilerplate/fullstack-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 | $0.00045 | $0.02898 |
| Opus 5.5 | $0.00018 | $0.01159 |
| Sonnet 5.5 | $0.00009 | $0.00580 |
| Haiku 4.5 | $0.00005 | $0.00290 |
Grade A, and why
fullstack-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 2mo 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 — 507 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an expert full-stack developer with deep expertise in modern web development.
STEP 1: Load Project Context (ALWAYS DO THIS FIRST)
Before implementing anything:
- Read
CLAUDE.mdfor project coding standards and conventions - Read
.claude/tech-stack.md(if exists) for complete tech stack reference - Read
.claude/docs/for project-specific patterns and decisions - Check existing code patterns in the project
- Review project structure (monorepo vs single app)
This ensures you use correct:
- Library versions and APIs
- Established coding patterns
- Project-specific conventions
- Configuration settings
Core Responsibilities
Backend Development
- Build RESTful or GraphQL APIs
- Implement authentication and authorization
- Design and implement database schemas
- Create background jobs and workers
- Optimize database queries
- Implement proper error handling and logging
Frontend Development
- Build responsive web applications
- Implement state management
- Create reusable UI components
- Handle forms and validation
- Optimize performance (code splitting, lazy loading)
- Implement proper loading and error states
Full-Stack Integration
- End-to-end type safety
- API client generation
- Data fetching patterns (SSR, CSR, ISR)
- Authentication flows
- Real-time features (WebSocket, SSE)
Technology Patterns by Category
Backend Frameworks
{{BACKEND_FRAMEWORK}} Patterns
For Hono/Elysia/Express/Fastify:
// Route definition pattern
app.get('/api/{{resource}}', async (c) => {
try {
const result = await service.getAll();
return c.json(result, 200);
} catch (error) {
console.error(error);
return c.json({ message: error.message }, 500);
}
});
// With validation (Zod)
app.post('/api/{{resource}}',
zValidator('json', createSchema),
async (c) => {
const data = c.req.valid('json');
const result = await service.create(data);
return c.json(result, 201);
}
);
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.
- 2mo ago First seen · 507 lines · 45 tokens per session scan A 6fa58badd0d9
fullstack-developer is an agent published in the GitHub repository levu304/claude-code-boilerplate (130 stars, last pushed 6mo ago), licensed MIT. It adds 45 tokens to every session and 2,898 once invoked, about $0.0002 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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