CSV Upload API

A FastAPI backend for uploading, validating, and storing transaction data from CSV files. Designed for easy onboarding, robust testing, and rapid development.

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Project Structure

• main.py
  Entry point. Initializes FastAPI, sets up CORS, creates DB tables, and includes API routers.

• app/core/

  • database.py: Handles SQLAlchemy DB engine, session, and base class. Loads DB config from .env.

• app/uploads/

  • models.py: SQLAlchemy models (currently, the Transaction table).
  • routers.py: FastAPI endpoints for CSV upload and validation.
  • schemas.py: Pydantic response schemas.
  • services.py: Core logic for processing and merging CSV data into the DB.
  • validators.py: CSV column validation logic.

• app/tests/

  • conftest.py: Pytest fixtures for DB and FastAPI client.
  • test_*.py: Unit and integration tests for uploads, performance, and duplicate handling.

• alembic/
  Database migrations (see below for usage).

• Dockerfile
  Containerizes the app for production or local development.

• docker-compose.yml
  Orchestrates the app (and optionally a Postgres DB) for local development.

• .env
  Stores DB connection strings and secrets. You must create or update this before running the app!

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Quickstart (Local)

1. Clone the repo

   git clone <your-repo-url>
   cd csvup-server

2. Create .env file
   Copy .env.example (if present) or create .env with at least:

   DATABASE_URL=postgresql://<user>:<password>@<host>:<port>/<dbname>
   POSTGRES_DB=<dbname>
   POSTGRES_USER=<user>
   POSTGRES_PASSWORD=<password>
   

   Or, for SQLite (for quick testing):

   DATABASE_URL=sqlite:///./uploads.db
   

3. Install dependencies

   python3 -m venv venv
   source venv/bin/activate
   pip install -r requirements.txt

4. Run database migrations

   alembic upgrade head

5. Run the app

   uvicorn main:app --reload

   • Docs available at http://localhost:8000/

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Quickstart (Docker Compose)

1. Ensure your .env is set up (see above).

2. Start services

   docker-compose up --build

   The API will be available at http://localhost:8000/

Note:

The default docker-compose.yml expects an external Postgres DB (yours sincerely uses one hosted by Render.com free tier).
To use a local Postgres container, uncomment the db: service and related lines in docker-compose.yml.

Migrations:
The start.sh script automatically runs alembic upgrade head before starting the app in Docker.

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Alembic Migration Commands

• Create new migration

  alembic revision --autogenerate -m "description"

• Apply migrations

  alembic upgrade head

• Rollback last migration

  alembic downgrade -1

• Check current revision

  alembic current

• Show migration history

  alembic history

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Render Deployment

Render runs alembic upgrade head automatically before starting the app (see render.yaml), so your database is always up to date with the latest migrations.

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Running Tests

• With local Python pytest:

  pytest

Tests cover:

• Upload endpoint (valid, invalid, empty, malformed CSVs)
• Duplicate transaction handling
• Performance and edge cases

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Contribution Tips

• Folder meanings:

  • core/: Shared infra (DB, config)
  • uploads/: All upload logic, models, and validation
  • tests/: All test code and fixtures

• Major files:

  • main.py: App entrypoint
  • database.py: DB setup
  • models.py: DB schema
  • routers.py: API endpoints
  • services.py: Business logic
  • validators.py: Data validation

• Before pushing:

  • Run all tests (pytest)
  • Check .env is not committed (see .gitignore)

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FAQ

• Where do I add new endpoints?
  In app/uploads/routers.py.

• How do I add new DB fields?
  Update app/uploads/models.py and run migrations (if using Alembic).

• How do I test with a clean DB?
  The test suite uses an in-memory SQLite DB for isolation.

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Welcome aboard!
If you get stuck, check the code comments or ask a teammate.