Simple Booking

A lightweight, modular WordPress booking engine with Stripe, Google Calendar, and Microsoft Outlook integration.

Current release: v3.0.17 (stable)

Features

• Custom Post Types: Services and Bookings managed in WordPress admin
• Stripe Checkout: Secure payment processing with Stripe Checkout
• Google Calendar: Automatic event creation for bookings
• Microsoft Outlook Calendar: Automatic event creation with Microsoft Graph API integration
• Auto Google Meet: Optional per-service Google Meet link generation on event creation
• Staff Assignment UI: Assign active staff to services directly in Service editor
• Staff Calendar Dropdown: Auto-load available Google/Outlook calendars for each staff member
• Frontend Form: Simple shortcode [simple_booking_form]
• Webhook Processing: Real-time booking creation after payment
• Webhook Retry Queue: Background retry scheduling with admin diagnostics and manual controls
• Booking Management UX: Dedicated manage page and cleaner cancel/reschedule customer messaging
• Free Booking Support: Services without Stripe Price ID book instantly
• Service-Specific Forms: Scope form to one service via shortcode attributes
• Email Notifications: Confirmation emails sent automatically
• Tokenized Booking Management: Secure reschedule/cancel links included in confirmation emails
• Success/Cancel Pages: Automatic creation of dedicated redirect pages for better UX
• Meeting Link Audit: Booking-level source tracking (generated, static, none)
• Admin Override: Editable booking meeting link with validation and admin error notice

File Structure

simple-booking/
├── assets/
│   ├── css/
│   │   └── booking-form.css
│   └── js/
│       └── booking-form.js
├── includes/
│   ├── admin/
│   │   └── class-admin-settings.php
│   ├── booking/
│   │   └── class-booking-creator.php
│   ├── calendar/
│   │   ├── class-calendar-provider-manager.php
│   │   ├── interface-calendar-provider.php
│   │   └── providers/
│   │       ├── class-google-provider.php
│   │       ├── class-ics-provider.php
│   │       └── class-outlook-provider.php
│   ├── frontend/
│   │   └── class-booking-form.php
│   ├── google/
│   │   └── class-google-calendar.php
│   ├── outlook/
│   │   └── class-outlook-calendar.php
│   ├── post-types/
│   │   ├── class-booking-service.php
│   │   ├── class-booking.php
│   │   └── class-staff.php
│   ├── stripe/
│   │   └── class-stripe-handler.php
│   └── webhook/
│       ├── class-booking-webhook.php
│       └── class-stripe-webhook.php
├── composer.json
└── simple-booking.php

Installation

1. Install Dependencies

The plugin requires the Stripe PHP SDK. You have two options:

Option A: Using Composer (Recommended)

cd wp-content/plugins/simple-booking
composer install

Option B: Manual Download

1. Download Stripe PHP SDK from https://github.com/stripe/stripe-php
2. Extract to: wp-content/plugins/simple-booking/vendor/stripe-php/

2. Install Plugin

1. Upload the simple-booking folder to /wp-content/plugins/
2. Or install via WordPress admin: Plugins > Add New > Upload Plugin
3. Activate the plugin

Configuration

1. Configure Stripe

1. Go to Settings > Simple Booking in WordPress admin
2. Enter your Stripe API keys:

Stripe Keys (found in Stripe Dashboard > Developers > API keys):

• Publishable Key: pk_test_xxxxxxxxxxxxxx
• Secret Key: sk_test_xxxxxxxxxxxxxx
• Webhook Secret: whsec_xxxxxxxxxxxxxx

3. Create a Stripe Price ID:
   • Go to Stripe Dashboard > Products
   • Create a product or price
   • Copy the Price ID (starts with price_)

2. Configure Calendar Provider (Optional)

Choose your calendar provider in Settings > Simple Booking > Calendar Provider:

• ICS Feed: Default option, no OAuth required
• Google Calendar: Sync bookings to Google Calendar
• Microsoft Outlook: Sync bookings to Microsoft Outlook Calendar

Option A: Google Calendar

1. Go to Google Cloud Console
2. Create a new project
3. Enable Google Calendar API
4. Create OAuth 2.0 credentials:
   • Application type: Web application
   • Authorized redirect URIs: https://your-site.com/wp-json/simple-booking/v1/google/oauth
5. Copy credentials to plugin settings:
   • Client ID: xxxxxxxxxxxxxx.apps.googleusercontent.com
   • Client Secret: xxxxxxxxxxxxxx
6. Enter your Calendar ID (found in Google Calendar settings):
   • Calendar ID: xxxxxxxxxxxxxx@group.calendar.google.com
7. Click Save Settings
8. Click Connect / Authorize Google Calendar button to complete OAuth authorization

Note: The OAuth connection is optional. Without connecting, bookings will be created but won't sync to Google Calendar.

Option B: Microsoft Outlook Calendar

Prerequisites:

• Azure account with an Azure AD tenant (directory)
• If you don't have one:
  • Join the M365 Developer Program (free) OR
  • Sign up for Azure (free tier available)

Setup Steps:

1. Go to Azure Portal and sign in
2. Navigate to Azure Active Directory > App registrations
3. Click New registration:
   • Display name: Simple Booking
   • Supported account types: All Microsoft account users (or the closest equivalent shown in your tenant)
   • Redirect URI: Web - https://your-site.com/wp-json/simple-booking/v1/outlook/oauth
4. In the app Overview, confirm and copy:
   • Application (client) ID (required in plugin)
   • Directory (tenant) ID (reference only; plugin currently uses common OAuth endpoint)
   • State should be Activated
5. Go to Certificates & secrets > New client secret:
   • Description: Simple Booking Secret
   • Under Client credentials, copy the secret Value (not the Secret ID)
6. Go to API permissions > Add a permission:
   • Select Microsoft Graph > Delegated permissions
   • Add: Calendars.ReadWrite, offline_access
   • Click Grant admin consent (if required by your organization)
7. In app Overview > Redirect URIs, confirm there is 1 web URI and it matches your site callback URL exactly
8. In plugin settings:
   • Outlook Client ID: Paste the Application (client) ID
   • Outlook Client Secret: Paste the client secret value
   • Outlook Redirect URI: Auto-populated, copy this to Azure if needed
9. Click Save Settings
10. Click Connect / Authorize Outlook Calendar button to complete OAuth authorization

Note: The OAuth connection is optional. Without connecting, bookings will be created but won't sync to Outlook Calendar.

3. Add Stripe Webhook

1. Go to Stripe Dashboard > Developers > Webhooks
2. Add endpoint:
   • Endpoint URL: https://your-site.com/wp-json/simple-booking/v1/webhook
3. Select event: checkout.session.completed
4. Copy the Webhook Secret to plugin settings

Creating Services

1. Go to Services in WordPress admin menu
2. Click Add New
3. Enter service name (e.g., "Consultation")
4. Fill in Service Details:
   • Duration: Service duration in minutes
   • Stripe Price ID: The price ID from Stripe
   • Active: Check to make available for booking
5. Publish

Using the Booking Form

Add the booking form to any page using the shortcode:

[simple_booking_form]

Single-service form examples:

[simple_booking_form service_id="123"]
[simple_booking_form service="consultation"]

How It Works

1. Customer selects a service and date/time
2. Fills in contact information
3. Clicks submit (Proceed to Payment for paid, Book Now for free)
4. Paid services: redirected to Stripe Checkout
5. Paid services: Stripe sends webhook after payment
6. Free services: booking is created immediately (no Stripe)
7. Customer is redirected to:
   • Booking Confirmed page (if configured)
   • Homepage fallback with session_id if success page is missing
8. Plugin creates:
   • Booking post in WordPress
   • Calendar event in configured provider (Google/Outlook/ICS fallback behavior)
   • Confirmation email to customer

Webhook delivery note:

• booking.created webhooks use background retries on rate-limit/server errors so booking creation stays responsive
• Admin diagnostics and controls are available in Settings > Simple Booking > Webhook Settings

Security

• All inputs are sanitized
• Nonce verification on forms
• Stripe signature verification on webhooks
• WordPress coding standards followed

Pre-release Checklist

• Ensure test override is disabled in production: SIMPLE_BOOKING_FORCE_PRO must be removed or set to boolean false (not string 'false')
• Verify Calendar Provider is set intentionally (ics, google, or outlook) in Settings > Simple Booking
• Confirm Google/Outlook credentials persist after provider switching in settings
• Run one paid cancel flow and confirm only one refund is attempted (repeat cancel should be blocked)
• Confirm no PHP fatal errors in debug.log after booking create/reschedule/cancel smoke test

Stabilization Smoke Checklist (v3.0.15 candidate)

Run this quick validation pass after deploys touching booking, calendar, email, or webhook logic.

• Google path: create, reschedule, cancel; verify calendar event CRUD and confirmation email
• Outlook path: create, reschedule, cancel; verify calendar event CRUD and confirmation email
• Staff calendar routing: verify selected staff calendar is used for create and delete flows
• Google Meet behavior: verify Meet link is generated when supported and event still creates when fallback is needed
• Webhook queue behavior: force endpoint 429 and verify booking remains fast while retry is deferred
• Admin queue controls: run due retries now; clear far-future retries in test context; verify queue table updates
• Booking data integrity: ensure assigned staff and calendar metadata persist across reschedule/cancel lifecycle