Files
resolutionflow/backend
Michael Chihlas 06200fabb1 fix(billing): make Stripe webhook idempotency atomic so failed handlers can retry
Previously `apply_subscription_event` committed the StripeEvent idempotency
row before invoking the handler, then the handlers each committed their own
mutations. If a handler raised mid-flight (transient DB error, network blip,
race), the idempotency mark was already persisted — Stripe's retry would hit
the IntegrityError branch and silently return False, and the subscription
state would permanently desync from Stripe.

Switch to a single atomic transaction:
- Insert the StripeEvent + flush (catch IntegrityError on duplicate event_id).
- Run the handler.
- Commit on success; roll back the entire transaction on failure and re-raise.

Drop the four `db.commit()` calls inside `_handle_*` so the outer caller owns
commit. The webhook endpoint already lets exceptions propagate, so a 500
response now correctly tells Stripe to retry.

Tests: three new regression cases in test_stripe_webhook_handler.py covering
handler failure (no idempotency mark persisted), retry-after-failure success,
and duplicate-event-id skip.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-07 01:36:13 -04:00
..

Troubleshooting Decision Tree - Backend API

FastAPI backend for the Troubleshooting Decision Tree application.

Quick Start

1. Set up Python environment

cd backend
python -m venv venv

# Windows
venv\Scripts\activate

# macOS/Linux
source venv/bin/activate

pip install -r requirements.txt

2. Start PostgreSQL database

Using Docker:

docker-compose up -d

Or install PostgreSQL locally and create a database:

CREATE DATABASE decision_tree;

3. Configure environment

Copy the example env file and update as needed:

cp .env.example .env

4. Run database migrations

alembic upgrade head

5. Start the server

uvicorn app.main:app --reload --host 0.0.0.0 --port 8000

The API will be available at:

API Endpoints

Authentication

  • POST /api/v1/auth/register - Register new user
  • POST /api/v1/auth/login - Login (form data)
  • POST /api/v1/auth/login/json - Login (JSON body)
  • POST /api/v1/auth/refresh - Refresh token
  • GET /api/v1/auth/me - Get current user
  • POST /api/v1/auth/logout - Logout

Trees

  • GET /api/v1/trees - List all trees
  • GET /api/v1/trees/categories - List categories
  • GET /api/v1/trees/search?q=query - Search trees
  • GET /api/v1/trees/{id} - Get specific tree
  • POST /api/v1/trees - Create tree (engineer/admin)
  • PUT /api/v1/trees/{id} - Update tree (engineer/admin)
  • DELETE /api/v1/trees/{id} - Delete tree (admin)

Sessions

  • GET /api/v1/sessions - List user's sessions
  • GET /api/v1/sessions/{id} - Get specific session
  • POST /api/v1/sessions - Start new session
  • PUT /api/v1/sessions/{id} - Update session
  • POST /api/v1/sessions/{id}/complete - Complete session
  • POST /api/v1/sessions/{id}/export - Export session

Development

Create new migration

alembic revision --autogenerate -m "description"

Run migrations

alembic upgrade head

Rollback migration

alembic downgrade -1

Project Structure

backend/
├── alembic/              # Database migrations
│   └── versions/
├── app/
│   ├── api/
│   │   ├── endpoints/    # API route handlers
│   │   ├── deps.py       # Dependencies (auth, etc.)
│   │   └── router.py     # Main router
│   ├── core/
│   │   ├── config.py     # Settings
│   │   ├── database.py   # DB connection
│   │   └── security.py   # JWT, password hashing
│   ├── models/           # SQLAlchemy models
│   ├── schemas/          # Pydantic schemas
│   └── main.py           # FastAPI app
├── tests/
├── alembic.ini
├── docker-compose.yml
├── requirements.txt
└── README.md