IntelliSignup Documentation
A Modern, Privacy-First Community Coordination, Claims & Dynamic Questionnaire Platform
IntelliSignup is deployed and operating live in production at intellisignup.net. It provides a frictionless sign-up experience for participants, robust multi-user accounts for organizers, automated background reminder workers, native spreadsheet analytics generation, and deep anti-spam cyber defenses.
Product Vision & Motivation
Coordinating group efforts—such as funeral meals, church ward activities, school fundraisers, volunteer service shifts, sports team snacks, and community potlucks—has historically relied on clunky, ad-cluttered platforms like SignUpGenius or rigid, impersonal shared spreadsheets.
IntelliSignup was engineered from the ground up to solve these core pain points:
Participants never need to create an account, remember passwords, or download an app. They can view signups and claim slots in under 30 seconds with mobile-first responsiveness.
Shielded by invisible honeypots, disposable email domain filters, sub-addressing blocks, IP rate limiters, and optional Cloudflare Turnstile passive verification.
Generates actual native Microsoft Excel and Google Sheets workbooks (.xlsx) with embedded formula-linked vector charts (Pie, Donut, Bar, Line) using openpyxl.
Seamless integration with Google Calendar API via OAuth2 (with AES-256 encrypted refresh tokens) alongside standard Apple and Outlook .ics calendar invitations.
End-to-End System Pipeline
IntelliSignup utilizes an asynchronous, multi-tiered architecture that isolates public guest actions from sensitive organizer credentials and background processing queues:
Clean mobile-friendly UI, Chart.js graphs, copy-to-clipboard actions, honeypots, and Turnstile tokens.
SSL termination, Let's Encrypt certificates, static asset caching (7-day immutable), and reverse proxying.
WSGI worker processes, rate limiting engines, CSRF checks, openpyxl reporting, and SQLAlchemy ORM.
Systemd 15-min reminder timer, SMTP email delivery, Fernet secret encryption, and Google OAuth API.
Technology Stack
The platform is constructed with modern, battle-tested open-source libraries emphasizing high performance, low resource overhead, and maximum maintainability:
| Component | Technology | Version / Specification | Purpose & Role |
|---|---|---|---|
| Web Framework | Flask (Python) | 3.1.x / Python 3.12 | Core routing, request context, session management, and template rendering. |
| Database & ORM | SQLAlchemy & Alembic | Flask-SQLAlchemy / Flask-Migrate | Schema modeling, migrations, foreign key constraints, and relational joins. |
| Spreadsheet Engine | openpyxl | 3.1.x | Native generation of Excel workbooks with formula-driven vector charts and styling. |
| Cryptography | cryptography (Fernet) | AES-128-CBC / HMAC-SHA256 | Encrypting OAuth refresh tokens and confidential integration credentials at rest. |
| Email Dispatcher | Flask-Mail / itsdangerous | SMTP / URLSafeTimedSerializer | Cryptographic email verification tokens, password resets, and reminder notices. |
| Anti-Spam & Bot Defense | Cloudflare Turnstile | Siteverify API v0 | Privacy-first passive human verification without puzzle captchas. |
| External Calendar | Google Calendar API | v3 / google-auth-oauthlib | Two-way event scheduling, description updating, and participant roster sync. |
| WSGI Server | Gunicorn | 22.x+ | Pre-fork worker model managing concurrent HTTP requests on localhost port 8581. |
| Process Supervision | systemd | Linux systemd services & timers | Daemon supervision, automated restarting, and 15-minute scheduled reminder cron. |
System Specifications & File Locations
/home/nelsonserver/websites/intellisignup/
├── app/
│ ├── __init__.py # Flask factory, extensions (Mail, DB, LoginManager)
│ ├── models.py # SQLAlchemy entities (User, Event, Item, Claim, CustomForm, etc.)
│ ├── routes.py # HTTP route handlers, export engines, and public endpoints
│ ├── security.py # Rate limiting, disposable email blocklist, Fernet AES, Turnstile
│ ├── mail_utils.py # Templated notifications, reminders, serializers, and activity logs
│ ├── google_calendar.py # Google OAuth2 flow, credential management, event/claim sync
│ ├── excel_charts.py # openpyxl workbook generator with native Excel charts
│ ├── static/ # CSS stylesheets, UI assets, and branding logos
│ └── templates/ # Jinja2 templates (dashboard, event_detail, questionnaires, emails)
├── instance/
│ ├── intellisignup.db # Production SQLite database storage
│ └── email_activity.log # Real-time JSON log of all outbound emails
├── migrations/ # Alembic version tracking files
├── nginx/
│ └── intellisignup.conf # Nginx reverse proxy virtual host definition
├── systemd/
│ ├── intellisignup.service # Primary Gunicorn web service
│ ├── intellisignup-reminders.service # Oneshot reminder delivery task
│ └── intellisignup-reminders.timer # 15-minute systemd timer trigger
├── send_reminders.py # Standalone CLI script executed by systemd timer
└── gunicorn_config.py # Worker count, timeouts, and binding configurationDocumentation Chapters
Explore the complete operational and technical documentation for the IntelliSignup platform:
Item-based vs time-slot signups, guest claiming, participant self-service, waitlist promotion, diff detection, and roster print sheets.
2. Dynamic Forms & Spreadsheets ➔Questionnaire builder, supported field types, live Chart.js graphs, public sharing, and the openpyxl native Excel chart generator.
3. Security & Anti-Spam Hardening ➔Honeypot defense, disposable email blocking, sliding-window rate limiting, Cloudflare Turnstile, and AES-256 Fernet secrets encryption.
4. Integrations & Notifications ➔Google Calendar 2-way synchronization, Apple iCal feeds, transactional email dispatch, automated reminders, and local analytics.
5. Operations & Deployment ➔Environment variables, systemd units, Nginx SSL configuration, Alembic migrations, and the NelsonServer dual-push Git pipeline.