Document QA RAG (FastAPI + React + Notebook)

This repository contains a complete Retrieval-Augmented Generation (RAG) workflow:

• Backend API in app/
• Frontend client in front/
• Notebook prototype in notebooks/

The system accepts only .txt and .pdf, does not persist uploaded files, and supports streamed answers.

The frontend is managed with Yarn 4.17.1 through Corepack and is deployed with Wrangler. The main CI workflow validates the backend with pytest and the frontend with a Yarn 4 immutable install plus a production build.

Repository Structure

• app/ FastAPI backend for RAG queries
• front/ React + Vite + TypeScript frontend
• notebooks/ Jupyter notebook prototype and local document workspace
• requirements.txt Python dependencies for backend/notebook

Prerequisites

• Python 3.10+
• Node.js 24+
• Corepack-enabled Yarn 4.17.1
• A Hugging Face token

1) Clone and Install

git clone <your-repo-url>
cd doc_rag
pip install -r requirements.txt
cd front
yarn install
cd ..

2) Run Backend (FastAPI)

uvicorn app.main:app --reload

Backend docs:

• Swagger UI: http://localhost:8000/docs

3) Run Frontend

cd front
yarn dev

Open the URL printed by Vite (typically http://localhost:5173).

To deploy the frontend through Cloudflare from the front/ directory:

yarn deploy

4) Use the App

• Paste your Hugging Face token in the frontend (stored in browser localStorage)
• Upload a .txt or .pdf
• Enter a question (up to 1,000 characters)
• Toggle stream on/off and submit

Environment Variables (Backend)

Optional backend variables:

• CORS_ALLOWED_ORIGINS (comma-separated)
• EMBEDDING_MODEL
• LLM_MODEL
• CHUNK_SIZE
• CHUNK_OVERLAP
• NUM_RETRIEVED_DOCS
• HUGGINGFACE_API_KEY (fallback token if frontend token is not provided)

Notes

• Uploaded files are processed in-memory and are not stored by the API.
• Frontend install and build should use Yarn 4.17.1 with Corepack enabled.
• Frontend build check:

cd front
yarn build

Security for Public Repo

• Never commit .env or real API keys.
• Use .env.example as template and keep real values only in local env / deployment secret manager.
• Frontend sends token using Authorization: Bearer <token> at request time.
• If you suspect a token leak, rotate/revoke it immediately in Hugging Face settings.

If a secret was committed in git history, rewrite history before publishing:

git filter-repo --path .env --invert-paths
git push --force --all
git push --force --tags

Folder Docs

• app/README.md
• front/README.md
• notebooks/README.md