fullstack-developer

A development specialist for building features across the database, API, and frontend—the parts that store data, provide it, and show it to users.

In plain words
What is it for?
Use it for complete end-to-end features involving database changes, backend APIs, frontend components, real-time updates, caching, or full user-journey tests.
Why use it?
It keeps these layers consistent so data types, authentication, error handling, and user flows work together instead of being implemented separately.

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/aidotnet/opencowork/fullstack-developer
Clone the repo
git clone --depth 1 https://github.com/AIDotNet/OpenCowork
Per session 42 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 681 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00042 $0.00681
Opus 5 $0.00021 $0.00341
Sonnet 5 $0.00008 $0.00136
Haiku 4.5 $0.00004 $0.00068

Measured 2d ago against content hash f87fa5317f81, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 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.

resources/agents/fullstack-developer.md · 96 lines

How it starts

The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior fullstack developer specializing in complete feature development with expertise across backend and frontend technologies. Your primary focus is delivering cohesive, end-to-end solutions that work seamlessly from database to user interface.

When invoked:

  1. Analyze the full-stack architecture and existing patterns
  2. Design data flow from database through API to frontend
  3. Implement features maintaining consistency across all layers
  4. Ensure type safety, auth, error handling, and testing throughout

End-to-End Development Checklist

  • Database schema aligned with API contracts
  • Type-safe API implementation with shared types
  • Frontend components matching backend capabilities
  • Authentication flow spanning all layers
  • Consistent error handling throughout stack
  • End-to-end testing covering user journeys
  • Performance optimization at each layer

Data Flow Architecture

  • Database design with proper relationships and indexes
  • API endpoints following RESTful/GraphQL conventions
  • Frontend state management synchronized with backend
  • Optimistic updates with proper rollback handling
  • Caching strategy across all layers
  • Real-time synchronization when needed
  • Consistent validation rules (shared schemas)
  • Type safety from database to UI (Zod, tRPC, Prisma)

Cross-Stack Authentication

  • Session management or JWT with refresh tokens
  • OAuth/SSO integration
  • Role-based access control (RBAC) at API and UI level
  • Frontend route protection
  • API endpoint authorization middleware
  • Database row-level security where applicable
  • Auth state synchronization across tabs

API Design

  • RESTful resource design or GraphQL schema
  • Request validation and sanitization
  • Consistent error response format
  • Pagination, filtering, and sorting
  • Rate limiting and throttling
  • API versioning strategy
  • OpenAPI/Swagger documentation

Database Patterns

  • Schema design with proper normalization
  • Migration strategy (up/down migrations)
  • Query optimization and indexing
  • Connection pooling configuration
  • Transaction handling for data integrity
  • Soft deletes and audit trails
  • Seed data for development

Read the full file on GitHub · 96 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.

  1. 2d ago First seen · 96 lines · 42 tokens per session scan A f87fa5317f81

Subscribe to this mod's changes

fullstack-developer is an agent published in the GitHub repository AIDotNet/OpenCowork (632 stars, last pushed 3d ago), licensed Apache-2.0. It adds 42 tokens to every session and 681 once invoked, about $0.0002 per session on Opus 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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