CLAUDE.md Template: Angular Material + FastAPI Paddle Payments Starter

Overview

CLAUDE.md template is a copyable CLAUDE.md template page for the Angular Material + FastAPI Paddle Payments stack. It provides a ready to paste Claude Code block and a stack specific project scaffold. Use this to bootstrap a consistent CLAUDE.md workflow across your project.

Direct answer summary: This CLAUDE.md template gives you a ready to paste Claude Code block and a starter project layout for Angular Material frontend, FastAPI backend, and Paddle payments integration.

When to Use This CLAUDE.md Template

• Starting a new Paddle powered SaaS with a modern Angular Material frontend and a FastAPI backend
• You want a consistent CLAUDE.md block that documents roles, architecture, and rules
• You need stack specific validation and security guidance
• You require a repeatable file structure and deployment notes

Copyable CLAUDE.md Template

# CLAUDE.md

Project role
Architecture rules
File structure rules
Authentication rules
Database rules
Validation rules
Security rules
Testing rules
Deployment rules
Things Claude must not do

Recommended Project Structure

angular-material-fastapi-paddle-payments/
├─ frontend/
│  ├─ src/
│  │  ├─ app/
│  │  │  ├─ components/
│  │  │  └─ services/
│  │  └─ index.html
│  ├─ angular.json
│  └─ package.json
├─ backend/
│  ├─ main.py
│  ├─ app/
│  │  ├─ api/
│  │  ├─ models/
│  │  ├─ schemas/
│  │  └─ core/
│  ├─ requirements.txt
│  └─ tests/
└─ payments/
   └─ paddle/
      ├─ webhook_handler.py
      └─ paddle_client.py

Core Engineering Principles

• Principle one not to blur lines between frontend and backend responsibilities
• Keep contracts stable using explicit API schemas
• Favor modular components with clear interfaces
• Readable CLAUDE.md blocks that can be pasted verbatim
• Observability and testability baked in from the start

Code Construction Rules

• Frontend code must use Angular Material components for UI consistency
• Backend must expose REST API under /api with strict typing
• Use Pydantic models for validation on FastAPI endpoints
• Store secrets in environment variables, not in code
• Webhook handler must verify Paddle signatures
• Do not hardcode credentials or API keys
• Do not bypass authentication checks in any endpoint

Security and Production Rules

• Validate all inputs and responses for API endpoints
• Configure TLS in production and enforce HTTPS
• Verify Paddle webhook signatures and IP whitelisting where applicable
• Use JWT or OAuth2 for user sessions
• Limit CORS to trusted frontends

Testing Checklist

• Unit tests for FastAPI endpoints using pytest
• Integration tests covering payment flow with Paddle sandbox
• Frontend tests for Angular components with Jasmine/Karma or Jest
• End-to-end tests for payment checkout and webhook handling
• CI should run tests on push and PR

Common Mistakes to Avoid

• Overreliance on mock data in production paths
• Skipping webhook verification or signature checks
• Hardcoding secrets in the CLAUDE.md template block
• Ignoring API versioning and contract drift
• Disregarding security headers and CSP

FAQ

What is included in this CLAUDE.md Template

A copyable CLAUDE.md block plus a stack specific project scaffold and rules

Which stack does this template cover

Angular Material for frontend, FastAPI for backend, Paddle for payments

How do I use the CLAUDE.md block

Copy the block into CLAUDE.md in your repo and customize placeholders

Does this template include security guidance

Yes, including Paddle webhook verification and deployment notes

Can I adapt this for other payment providers

Yes, replace Paddle specific code with other provider handlers