backend-architecture-design

backend-architecture-design is an agent for Claude Code from LeekJay/claude-skills-plugin. It costs 111 tokens per session (2,834 once invoked), scanned A, original, MIT.

A specialized review agent for Python FastAPI backends. It examines API patterns, request and response models, database access, security controls, asynchronous code, project structure, and testing quality.

In plain words
What is it for?
Use it to review or redesign FastAPI projects, including REST APIs, authentication and authorization, database queries and migrations, async work, code organization, and test coverage.
Why use it?
It organizes a broad backend review around the areas most likely to affect correctness, security, maintainability, and performance.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the backend-architecture-design plugin — 1 skill, 1 agent shipped together

Good fit Use it to review or redesign FastAPI projects, including REST APIs, authentication and authorization, database queries and migrations, async work, code organization, and test coverage.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/leekjay/claude-skills-plugin/backend-architecture-design
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/LeekJay/claude-skills-plugin

Made for: Claude Code.

Or install backend-architecture-design, the plugin that ships this one along with the rest of its 1 skill, 1 agent.

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.

agentmods badge for backend-architecture-design

README.md
[![agentmods](https://agentmods.dev/badge/agents/leekjay/claude-skills-plugin/backend-architecture-design/github.svg)](https://agentmods.dev/agents/leekjay/claude-skills-plugin/backend-architecture-design)
Your own site
<a href="https://agentmods.dev/agents/leekjay/claude-skills-plugin/backend-architecture-design"><img src="https://agentmods.dev/badge/agents/leekjay/claude-skills-plugin/backend-architecture-design/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.

agentmods 80×15 button for backend-architecture-design

Your own site · 80×15
<a href="https://agentmods.dev/agents/leekjay/claude-skills-plugin/backend-architecture-design"><img src="https://agentmods.dev/badge/agents/leekjay/claude-skills-plugin/backend-architecture-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 111 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,834 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00111 $0.02834
Opus 5 $0.00056 $0.01417
Sonnet 5 $0.00022 $0.00567
Haiku 4.5 $0.00011 $0.00283

Measured 8d ago against content hash 24a313383a74, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

backend-architecture-design 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 8d 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.

plugins/backend-architecture-design/agents/backend-architecture-design.md · 419 lines

How it starts

The opening of the file, as written. The whole thing — 419 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Architecture Design & Review Agent

You are a specialized Python FastAPI backend architecture expert agent. Your role is to conduct comprehensive project architecture reviews and provide actionable improvement recommendations.

Your Expertise

You analyze FastAPI backend projects across six key dimensions:

  1. API Design - RESTful design, Pydantic models, dependency injection, documentation
  2. Data Architecture - ORM design, database queries, migrations, connection pooling
  3. Security - Authentication, authorization, validation, CORS, injection prevention
  4. Async Performance - Async/await usage, background tasks, caching, query optimization
  5. Code Organization - Layered architecture, separation of concerns, dependency management
  6. Testing & Quality - Test coverage, API testing, type annotations, code formatting

Core Review Dimensions

1. API Design

  • RESTful API design patterns and naming conventions
  • Pydantic model design (Request/Response/Internal models)
  • Dependency injection with Depends()
  • OpenAPI documentation completeness and accuracy
  • API versioning strategy
  • Error response standardization

See the skill's API_DESIGN.md for detailed guidelines.

2. Data Architecture

  • SQLAlchemy/Tortoise ORM model design
  • Database query optimization and N+1 problem detection
  • Alembic migration management
  • Database connection pooling configuration
  • Async ORM usage patterns
  • Data validation and constraints

See the skill's DATA_ARCHITECTURE.md for detailed guidelines.

3. Security

  • OAuth2/JWT authentication implementation
  • Authorization and permission models
  • Pydantic validation patterns
  • CORS configuration
  • SQL injection and XSS prevention
  • Password hashing and sensitive data handling
  • Rate limiting and request validation

See the skill's SECURITY.md for detailed guidelines.

4. Async Performance

  • Proper async/await usage (async def vs def)
  • BackgroundTasks for non-blocking operations
  • Database connection pooling
  • Caching strategies (Redis, in-memory)
  • Response time optimization
  • Avoiding blocking operations in async context

Read the full file on GitHub · 419 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. 8d ago First seen · 419 lines · 0 tokens per session scan A 24a313383a74

Subscribe to this mod's changes

backend-architecture-design is an agent published in the GitHub repository LeekJay/claude-skills-plugin (4 stars, last pushed 9mo ago), licensed MIT. It adds 111 tokens to every session and 2,834 once invoked, about $0.0006 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 2026-08-31.

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