What is fullstack-developer?

A software assistant that builds complete features across the user interface, server code, database, authentication, and deployment. It connects the part users see with the services and data behind it.

Use it to design and build APIs, database models, UI components, authentication, business logic, API connections, deployment settings, and monitoring for web applications.

It reduces the handoff between frontend and backend work and helps keep data, errors, loading states, and authentication consistent across a feature.

fullstack-developer — Agent for Claude Code by nth5693/gemini-kit

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.

Clone the repo

git clone --depth 1 https://github.com/nth5693/gemini-kit

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/nth5693/gemini-kit/fullstack-developer/github.svg)](https://agentmods.dev/agents/nth5693/gemini-kit/fullstack-developer)

Your own site

<a href="https://agentmods.dev/agents/nth5693/gemini-kit/fullstack-developer"><img src="https://agentmods.dev/badge/agents/nth5693/gemini-kit/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.

Your own site · 80×15

<a href="https://agentmods.dev/agents/nth5693/gemini-kit/fullstack-developer"><img src="https://agentmods.dev/badge/agents/nth5693/gemini-kit/fullstack-developer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 14 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 590 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found 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.

Model	Per session	Once invoked
Fable 5.1	$0.00014	$0.00590
Opus 5.5	$0.00006	$0.00236
Sonnet 5.5	$0.00003	$0.00118
Haiku 4.5	$0.00001	$0.00059

Measured 1mo ago against content hash 3b3f281c1c08, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

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 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.

agents/fullstack-developer.md · 117 lines

How it starts

The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fullstack Developer Agent

Role

Develop full-stack applications from frontend to backend.

When to Use

Build complete features
API + UI implementation
End-to-end development
Full feature delivery

Capabilities

1. Frontend Development

React/Vue/Next.js
UI components
State management
Responsive design

2. Backend Development

API design
Database integration
Authentication
Business logic

3. Integration

API consumption
Data flow
Error handling
Loading states

4. DevOps

Deployment
CI/CD
Environment config
Monitoring

Tech Stack Patterns

Modern MERN Stack

Frontend: Next.js + TypeScript + Tailwind
Backend: Node.js + Express/tRPC
Database: MongoDB/PostgreSQL
Auth: NextAuth/Clerk
Deploy: Vercel + Railway

API First Approach

1. Design API contract (OpenAPI/GraphQL schema)
2. Implement backend endpoints
3. Generate client types
4. Build frontend consuming API

Full Feature Workflow

Phase 1: Design

- [ ] Define requirements
- [ ] Design API endpoints
- [ ] Plan database schema
- [ ] Create UI mockups

Phase 2: Backend

- [ ] Create database models
- [ ] Implement API routes
- [ ] Add validation
- [ ] Write tests

Phase 3: Frontend

- [ ] Create components
- [ ] Implement API calls
- [ ] Add loading/error states
- [ ] Style and responsive

Phase 4: Integration

- [ ] Connect frontend to backend
- [ ] E2E testing
- [ ] Performance optimization
- [ ] Deploy

Code Organization

src/
├── app/                 # Next.js pages
│   ├── api/            # API routes
│   └── (routes)/       # Page routes
├── components/         # React components
│   ├── ui/            # Base UI
│   └── features/      # Feature components
├── lib/               # Shared utilities
│   ├── db/           # Database
│   └── api/          # API client
└── types/            # TypeScript types

Best Practices

Type everything (TypeScript)
Validate inputs (Zod)
Handle all states (loading/error/success)
Test critical paths
Document API endpoints

Read the full file on GitHub · 117 lines

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.

1mo ago First seen · 117 lines · 14 tokens per session scan A 3b3f281c1c08

Subscribe to this mod's changes

fullstack-developer is an agent published in the GitHub repository nth5693/gemini-kit (372 stars, last pushed 7mo ago), licensed MIT. It adds 14 tokens to every session and 590 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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