backend-development-index

An index that directs backend developers to guidance for building web services, machine-learning services, APIs, data models, and dependency structures. Backend development means building the server-side parts of an application.

In plain words
What is it for?
Use it when starting a service, integrating machine-learning models, designing REST APIs, organising validation models, managing dependencies, or preventing circular imports.
Why use it?
It helps you find the relevant engineering rules without searching through every backend guide.

Cursor rule for Cursor

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 rules/rm2thaddeus/pixel_detective/backend-development-index
Clone the repo
git clone --depth 1 https://github.com/rm2thaddeus/Pixel_Detective

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,876 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00000 $0.01876
Opus 5 $0.00000 $0.00938
Sonnet 5 $0.00000 $0.00375
Haiku 4.5 $0.00000 $0.00188

Measured 2d ago against content hash 988aa687b6e7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

backend-development-index scanned grade A with 1 finding 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

2. **Service Health:** `curl localhost:8000/health` (microservice-patterns)
backend/.cursor/rules/backend-development-index.mdc · 211 lines

How it starts

The opening of the file, as written. The whole thing — 211 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Development Master Index

🎯 COMPLETE BACKEND DEVELOPMENT GUIDE

This index provides comprehensive guidance for backend development based on proven patterns from ingestion_orchestration_fastapi_app and ml_inference_fastapi_app.

📋 RULE SELECTION GUIDE - Choose Your Path:

🚀 New Service Development

START HERE: fastapi-microservice-patterns.mdc

  • Complete service lifecycle management patterns
  • Lifespan context managers for startup/shutdown
  • Background task orchestration
  • Service health monitoring
  • Production deployment patterns
🤖 ML/AI Service Development

START HERE: ml-service-integration.mdc

  • GPU resource management patterns
  • Model loading and inference optimization
  • Async ML processing workflows
  • Memory-efficient batch processing
  • CUDA acceleration patterns
🔌 API Design & Data Modeling

START HERE: api-design-patterns.mdc

  • RESTful endpoint design patterns
  • Pydantic model organization
  • Request/response validation
  • Error handling strategies
  • API versioning approaches
🔗 Dependency Management & Architecture

START HERE: fastapi-dependency-injection.mdc

  • Circular import prevention
  • Dependency injection patterns
  • Shared resource management
  • Application state management
  • Testing with dependencies

🏗️ ARCHITECTURE DECISION FLOWCHART

Step 1: Service Type Classification

Is your service primarily for:
├── Data Processing/Ingestion → Use `fastapi-microservice-patterns.mdc`
├── ML Inference/Training → Use `ml-service-integration.mdc`  
├── API Gateway/CRUD → Use `api-design-patterns.mdc`
└── Complex Multi-Service → Use ALL rules in sequence

Step 2: Implementation Pattern Selection

For Data Processing:
├── Background Tasks → Celery + Redis patterns (microservice-patterns)
├── Real-time Processing → WebSocket patterns (api-design-patterns)
├── Batch Processing → Job queue patterns (microservice-patterns)
└── File Processing → Async file handling (microservice-patterns)

For ML Services:
├── GPU Inference → Lock patterns (ml-service-integration)
├── Model Serving → FastAPI + torch patterns (ml-service-integration)
├── Batch Inference → Queue patterns (microservice-patterns + ml-integration)
└── Real-time Inference → Streaming patterns (ml-service-integration)

For API Services:
├── CRUD Operations → Repository patterns (api-design-patterns)
├── Complex Queries → Query builder patterns (api-design-patterns)
├── File Uploads → Streaming upload patterns (api-design-patterns)
└── Authentication → JWT patterns (api-design-patterns)

Read the full file on GitHub · 211 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 · 211 lines · 0 tokens per session scan A 988aa687b6e7

Subscribe to this mod's changes

backend-development-index is a cursor rule published in the GitHub repository rm2thaddeus/Pixel_Detective (21 stars, last pushed 6mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,876 tokens. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.