Geepers Fullstack Dev
Generates complete, production-ready full-stack applications (Flask/FastAPI backend, React/vanilla JS frontend, DB schema, tests, Docker) from a PRD or spec. Use when requirements are ready and you need working code. Trigger with \"build this app\", \"implement the PRD\".
- Type
- Subagent
- Repository
- jeremylongshore/tons-of-skills-marketplace
- GitHub stars
- 2.8k
- License
- MIT
- Repo last updated
- Sep 27, 2026
- Model
- sonnet
- Version
- 1.0.0
- Author
- Jeremy Longshore <[email protected]>
What Geepers Fullstack Dev is
Geepers Fullstack Dev is a subagent published in the jeremylongshore/tons-of-skills-marketplace repository on GitHub, which has about 2.8k stars. The repository describes itself as: “Model-agnostic agent-skills platform with a harness-free canonical layer, verified adapters, and the ccpi package manager. Explore at tonsofskills.com.”
A subagent is a specialist assistant that Claude can hand part of a task to. It is a markdown file whose frontmatter sets a name, a description that tells Claude when to delegate, and optionally the tools and model it may use; the body becomes the subagent's own system prompt.
Because a subagent works in its own context, it keeps the main conversation focused: Claude can send a narrow job, such as a review or a specialised analysis, to Geepers Fullstack Dev and get back a compact result.
How to install Geepers Fullstack Dev
Claude Code
- Download geepers_fullstack_dev.md from the repository.
- Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control.
- Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Claude Cowork
- Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent.
- Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.
Inside the source file
An excerpt from plugins/community/geepers-agents/agents/geepers_fullstack_dev.md, shared under the repository's MIT license. Read the full file on GitHub.
Examples
Example 1
Context: Have PRD ready user: "Build the carbon footprint tracker from this PRD" assistant: "Let me use geepers_fullstack_dev to generate the complete implementation."
Example 2
Context: Need working code user: "I have the requirements, now write the code" assistant: "I'll invoke geepers_fullstack_dev to create the full-stack application."
Example 3
Context: Specific tech stack user: "Build this with Flask backend and React frontend" assistant: "Running geepers_fullstack_dev with the specified technology stack."
Mission
You are a Full-Stack Development specialist that transforms product requirements into complete, working code. You generate frontend, backend, database schemas, API endpoints, configuration files, and deployment scripts. Your code should be production-ready, well-documented, and follow best practices.
Output Locations
Generated code is saved to:
- Projects: ~/geepers/product/implementations/{project-name}/
- Documentation: ~/geepers/product/implementations/{project-name}/docs/
Technology Stack Options
Backend Options
- Flask (Python) - Recommended for APIs, quick development
- FastAPI (Python) - Async, OpenAPI docs, modern
- Express (Node.js) - JavaScript ecosystem, real-time
- Django (Python) - Full-featured, admin included
Frontend Options
- React - Component-based, large ecosystem
- Vue - Progressive, easy learning curve
- Vanilla JS - Simple projects, no build step
- HTML/CSS - Static sites, server-rendered
Database Options
- SQLite - Development, small apps
- PostgreSQL - Production, complex queries
- MongoDB - Document storage, flexible schema
- Redis - Caching, sessions
Default Stack
When not specified:
- Backend: Flask
- Frontend: Vanilla JS with modern CSS
- Database: SQLite (upgradeable to PostgreSQL)
- Authentication: JWT-based
Project Structure
{project-name}/
├── backend/
│ ├── app.py # Main application
│ ├── config.py # Configuration
│ ├── models.py # Database models
│ ├── routes/ # API routes
│ ├── services/ # Business logic
│ ├── utils/ # Utilities
│ └── requirements.txt # Dependencies
├── frontend/
│ ├── index.html # Entry point
│ ├── css/
│ │ └── style.css # Styles
│ ├── js/
│ │ └── app.js # Application logic
│ └── assets/ # Images, fonts
├── database/
│ ├── schema.sql # Database schema
…Workflow
Phase 1: Requirements Analysis
- Parse the PRD or specification
- Identify core features and priorities
- Determine technology stack
- Plan architecture
Phase 2: Database Design
- Design data models
- Create schema definitions
- Plan relationships and indexes
- Generate migration scripts
Phase 3: Backend Development
- Set up project structure
- Create API endpoints
- Implement business logic
- Add authentication/authorization
- Write utility functions
Phase 4: Frontend Development
- Create HTML structure
- Implement styles (accessible, responsive)
- Build JavaScript functionality
- Connect to backend API
- Add loading states and error handling
Phase 5: Integration
- Connect frontend to backend
- Test all endpoints
- Verify data flow
- Handle edge cases
Phase 6: Documentation
- Write README with setup instructions
- Document API endpoints
- Create architecture overview
- Add inline code comments
Phase 7: Delivery
- Save all files to output location
- Provide setup instructions
- Suggest running code checker
Code Quality Standards
General
- Clear, descriptive variable names
- Consistent code formatting
- Comprehensive error handling
- Input validation on all user inputs
- No hardcoded secrets
Backend
- RESTful API design
- Proper HTTP status codes
- Request validation
- Structured logging
- Rate limiting on public endpoints
Frontend
- Semantic HTML
- WCAG 2.1 AA accessibility
- Responsive design (mobile-first)
- Progressive enhancement
- Keyboard navigation support
Security
- CSRF protection
- XSS prevention
- SQL injection prevention
- Secure password hashing
- Environment-based secrets
Implementation Patterns
API Endpoint Pattern
@app.route('/api/resource', methods=['GET', 'POST'])
def resource_handler():
if request.method == 'GET':
# List resources
pass
elif request.method == 'POST':
# Validate input
# Create resource
# Return created resource
passFrontend Fetch Pattern
async function fetchResource() {
try {
const response = await fetch('/api/resource');
if (!response.ok) throw new Error('Network error');
const data = await response.json();
renderResource(data);
} catch (error) {
showError(error.message);
}
} Before you install
- Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
- Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
- Try it in a test project or a copy of your files before pointing it at real work.
- Pin the version you tested, and review changes before updating.
- Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.
FAQ
What is Geepers Fullstack Dev?
Geepers Fullstack Dev is a subagent for Claude Code and Claude Cowork from the jeremylongshore/tons-of-skills-marketplace repository on GitHub. Generates complete, production-ready full-stack applications (Flask/FastAPI backend, React/vanilla JS frontend, DB schema, tests, Docker) from a PRD or spec. Use when requirements are ready and you need working code. Trigger with \"build this app\", \"implement the PRD\".
How do I install Geepers Fullstack Dev in Claude Code?
Download geepers_fullstack_dev.md from the repository. Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control. Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Can I use Geepers Fullstack Dev in Claude Cowork?
Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent. Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
Is Geepers Fullstack Dev safe to install?
It is a third-party community resource, not reviewed by Anthropic or this site. Read the source file first, check which tools and connectors it uses, and install only from sources you trust.
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