💰 Billable

Auto-invoice clients the moment a calendar meeting ends. Zero manual work.

Billable is a Python automation system for freelancers and agencies that eliminates manual invoicing by automatically generating and sending invoices when a billable Google Calendar event ends.

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🚀 Overview

Freelancers lose revenue due to:

• Delayed invoicing
• Forgotten billing
• Manual time tracking
• Multi-step payment workflows

Billable solves this by fully automating the post-meeting billing pipeline.

Once a [BILLABLE] tagged calendar event ends, the system:

1. Calculates billable duration
2. Generates a PayPal invoice
3. Sends the invoice to the client
4. Posts a receipt in Slack
5. Sends a payment link via SMS
6. Triggers a follow-up reminder if unpaid

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⚙️ Tech Stack

• Python 3
• Flask
• Google Calendar API
• PayPal Invoicing REST API v2
• Slack Incoming Webhooks (Block Kit)
• Twilio Programmable SMS
• threading
• python-dotenv

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📦 Project Structure

billable/ ├── .env ├── .env.example ├── requirements.txt ├── config.py ├── app.py └── services/

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🔁 Core Workflow

Google Calendar → Detect event → Calculate amount → PayPal invoice → Slack → SMS → Follow-up

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🔐 Environment Variables

GOOGLE_CALENDAR_ID=primary
PAYPAL_CLIENT_ID=
PAYPAL_CLIENT_SECRET=
PAYPAL_MODE=sandbox
SLACK_WEBHOOK_URL=
TWILIO_ACCOUNT_SID=
TWILIO_AUTH_TOKEN=
TWILIO_FROM_NUMBER=+1XXXXXXXXXX
HOURLY_RATE=150
DEMO_MODE=true

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▶️ Running

python app.py

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🧪 Demo Endpoint

POST /trigger

{ "event_id": "demo-001", "title": "[BILLABLE] Strategy Session", "client_email": "client@example.com", "client_name": "Alex", "client_phone": "+923001234567", "duration_minutes": 45 }

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🧠 Key Features

• Automated invoicing pipeline
• Slack + SMS notifications
• PayPal invoice generation
• Failure-safe execution
• Event deduplication
• Demo mode support

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🔮 Future Work

• Stripe integration
• AI-based meeting tagging
• Web dashboard
• Persistent database