---
title: Backend Architecture
description: "**Initialization**: `app.py` creates the Flask app, loads `config.json` and environment variables, initializes databases, and registers all Blueprints in `modules/web/`. **Blueprints** (registered in `app.py`): - `site_bp` (`modules/web/views.py`): Home, analyzer, tag report. - `projects_bp` (`modules/web/projects.py`): Create, edit, settings, import/export. - `auth_bp` (`modules/web/auth.py`):…"
url: "https://erroranalyzer.com/docs/backend-architecture/"
updated: "2025-09-10"
category: Reference
---

# Backend Architecture

**Initialization**: `app.py` creates the Flask app, loads `config.json` and environment variables, initializes databases, and registers all Blueprints in `modules/web/`.

**Blueprints** (registered in `app.py`):

- `site_bp` (`modules/web/views.py`): Home, analyzer, tag report.
- `projects_bp` (`modules/web/projects.py`): Create, edit, settings, import/export.
- `auth_bp` (`modules/web/auth.py`): Login, register, profile.
- `api_bp` (`modules/web/api.py`): REST API for tags, annotations, notes, AI analysis, and more.
- `uploads_bp` (`modules/web/uploads.py`): Initial CSV uploads.
- `edit_bp` (`modules/web/edit.py`): Internal endpoints for legacy highlight edits.
- `compat_bp` (`modules/web/compat.py`): Redirects for deprecated URLs.