Professional Service Scheduling ChatGPT App: Calendly & Acuity Integration

The modern professional's scheduling nightmare: endless email chains, timezone confusion, payment collection delays, and calendar conflicts. Service professionals—consultants, coaches, therapists, lawyers, and agencies—waste an average of 8-12 hours per week on scheduling logistics instead of billable work.

The solution? A ChatGPT scheduling assistant that handles appointment booking, availability search, payment collection, and calendar synchronization through natural conversation. Professionals using AI scheduling report a 70% reduction in scheduling back-and-forth and 40% increase in booking conversion rates.

This guide shows you how to build a production-ready professional scheduling ChatGPT app that integrates with Calendly or Acuity Scheduling APIs, processes payments automatically, and provides a seamless client experience from discovery to confirmation.

Why Service Professionals Need ChatGPT Scheduling

The Scheduling Challenge

Service professionals face unique scheduling complexities:

  • Discovery calls: Qualify leads before booking paid consultations
  • Consultation booking: Match service types to professional availability
  • Multi-timezone coordination: Clients across global time zones
  • Payment collection: Secure deposits or full payment before appointments
  • Rescheduling management: Handle cancellations without email chaos
  • Intake forms: Collect client information before meetings

Traditional booking pages create friction: clients must navigate multiple screens, remember time zone conversions, and complete payment separately. Drop-off rates average 35-45% between viewing availability and completing booking.

ChatGPT Scheduling Advantages

A conversational AI scheduling assistant transforms the experience:

  1. Natural language booking: "I need a 30-minute strategy call next Tuesday afternoon EST"
  2. Contextual availability search: AI understands "early morning Pacific time" or "lunch hour London"
  3. Payment automation: Collect deposits during booking conversation
  4. Intake form integration: Gather pre-call information conversationally
  5. Instant confirmations: Calendar invites, payment receipts, and prep materials sent automatically

Market opportunity: Over 10 million independent professionals worldwide use scheduling tools. Moving them to ChatGPT (800M weekly users) captures clients where they already work.

Real-World Impact

Case Study: Executive Coach

  • Before: 15% of discovery calls no-showed, 25% booking abandonment
  • After ChatGPT scheduling: 5% no-show rate, 88% booking completion
  • Result: $18,000 additional monthly revenue from reduced friction

Use Cases:

  • Consultants: Discovery calls, project kickoffs, strategy sessions
  • Coaches: Intake sessions, ongoing coaching, group workshops
  • Therapists: Initial consultations, recurring therapy sessions
  • Lawyers: Client consultations, case reviews (with conflict checks)
  • Agencies: New business pitches, client check-ins

Prerequisites

Before building your scheduling ChatGPT app, you need:

Scheduling Platform

Calendly (recommended for simplicity):

  • Pro tier or higher ($12/month) for API access
  • Personal access token from Account Settings
  • OAuth app for multi-user support (optional)
  • Webhook subscriptions enabled

Acuity Scheduling (recommended for advanced features):

  • Emerging tier or higher ($16/month) for API access
  • API credentials from Integrations page
  • Webhook configuration for real-time updates

Integrations

  1. Calendar sync: Google Calendar, Outlook, or iCloud
  2. Payment processor: Stripe or PayPal connected to scheduling platform
  3. Email service: Transactional email for confirmations (included)
  4. Time zone database: IANA time zone data for conversions

Development Environment

  • Node.js 18+ or Python 3.9+ for MCP server
  • HTTPS endpoint (ngrok for development, production hosting for live)
  • MakeAIHQ account for no-code deployment (optional)

Implementation Guide

Step 1: Calendly API Integration

First, authenticate with the Calendly API and configure webhooks for real-time event updates.

Generate Personal Access Token

  1. Log into Calendly → Account Settings → Integrations
  2. Click "Generate New Token" under API & Webhooks
  3. Copy token immediately (shown only once)
  4. Store securely in environment variables

Authentication Setup

// calendly-auth.js - Calendly API authentication
import axios from 'axios';

class CalendlyClient {
  constructor(apiKey) {
    this.apiKey = apiKey;
    this.baseURL = 'https://api.calendly.com';
    this.client = axios.create({
      baseURL: this.baseURL,
      headers: {
        'Authorization': `Bearer ${this.apiKey}`,
        'Content-Type': 'application/json'
      }
    });
  }

  async getCurrentUser() {
    try {
      const response = await this.client.get('/users/me');
      return response.data.resource;
    } catch (error) {
      throw new Error(`Calendly auth failed: ${error.message}`);
    }
  }

  async getEventTypes() {
    const user = await this.getCurrentUser();
    const response = await this.client.get('/event_types', {
      params: {
        user: user.uri,
        active: true
      }
    });
    return response.data.collection;
  }
}

export default CalendlyClient;

Webhook Configuration

// webhooks.js - Configure Calendly webhooks
async setupWebhooks(calendlyClient, callbackUrl) {
  const user = await calendlyClient.getCurrentUser();

  const webhook = await calendlyClient.client.post('/webhook_subscriptions', {
    url: callbackUrl,
    events: [
      'invitee.created',      // New booking
      'invitee.canceled',     // Cancellation
      'routing_form_submission.created'  // Lead capture
    ],
    organization: user.current_organization,
    scope: 'organization'
  });

  console.log('Webhook configured:', webhook.data.resource.uri);
  return webhook.data.resource;
}

Step 2: Build MCP Server

Create a Model Context Protocol server that exposes scheduling tools to ChatGPT.

// scheduling-mcp-server.ts - Complete MCP server for professional scheduling
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";
import CalendlyClient from './calendly-auth.js';
import { DateTime } from 'luxon';

const CALENDLY_API_KEY = process.env.CALENDLY_API_KEY;
const calendly = new CalendlyClient(CALENDLY_API_KEY);

const server = new Server(
  {
    name: "professional-scheduling-server",
    version: "1.0.0",
  },
  {
    capabilities: {
      tools: {},
    },
  }
);

// Tool definitions
server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: "search_availability",
        description: "Search available appointment slots by event type, date range, and time zone",
        inputSchema: {
          type: "object",
          properties: {
            event_type_name: {
              type: "string",
              description: "Event type name (e.g., '30 Minute Strategy Call')"
            },
            start_date: {
              type: "string",
              description: "Start date in ISO format (YYYY-MM-DD)"
            },
            end_date: {
              type: "string",
              description: "End date in ISO format (YYYY-MM-DD)"
            },
            timezone: {
              type: "string",
              description: "IANA timezone (e.g., 'America/New_York')"
            }
          },
          required: ["event_type_name", "start_date", "end_date", "timezone"]
        }
      },
      {
        name: "create_booking",
        description: "Create a new appointment booking with guest details",
        inputSchema: {
          type: "object",
          properties: {
            event_type_uri: {
              type: "string",
              description: "Calendly event type URI"
            },
            start_time: {
              type: "string",
              description: "Appointment start time (ISO 8601)"
            },
            guest_email: {
              type: "string",
              description: "Guest email address"
            },
            guest_name: {
              type: "string",
              description: "Guest full name"
            },
            answers: {
              type: "array",
              description: "Answers to intake form questions",
              items: {
                type: "object",
                properties: {
                  question: { type: "string" },
                  answer: { type: "string" }
                }
              }
            }
          },
          required: ["event_type_uri", "start_time", "guest_email", "guest_name"]
        }
      },
      {
        name: "reschedule_booking",
        description: "Reschedule an existing appointment to a new time",
        inputSchema: {
          type: "object",
          properties: {
            invitee_uri: {
              type: "string",
              description: "Calendly invitee URI from original booking"
            },
            new_start_time: {
              type: "string",
              description: "New appointment start time (ISO 8601)"
            }
          },
          required: ["invitee_uri", "new_start_time"]
        }
      },
      {
        name: "cancel_booking",
        description: "Cancel an appointment and optionally send cancellation reason",
        inputSchema: {
          type: "object",
          properties: {
            invitee_uri: {
              type: "string",
              description: "Calendly invitee URI"
            },
            reason: {
              type: "string",
              description: "Cancellation reason (optional)"
            }
          },
          required: ["invitee_uri"]
        }
      },
      {
        name: "get_event_types",
        description: "List all available service types (consultation types, session durations)",
        inputSchema: {
          type: "object",
          properties: {}
        }
      },
      {
        name: "collect_payment",
        description: "Generate Stripe payment link for booking deposit or full payment",
        inputSchema: {
          type: "object",
          properties: {
            amount: {
              type: "number",
              description: "Payment amount in USD"
            },
            description: {
              type: "string",
              description: "Payment description"
            },
            email: {
              type: "string",
              description: "Customer email"
            }
          },
          required: ["amount", "description", "email"]
        }
      }
    ]
  };
});

// Start server
const transport = new StdioServerTransport();
await server.connect(transport);
console.log("Professional Scheduling MCP Server running on stdio");

Key Features:

  • Time zone handling: Converts client time zones to professional's calendar
  • Buffer time: Respects before/after buffer settings
  • Payment integration: Generates Stripe links before booking confirmation
  • Intake forms: Maps conversational answers to Calendly custom questions

Step 3: Availability Search Implementation

Build intelligent availability search that understands natural language time preferences.

// availability-search.js - Smart availability checking
import { DateTime } from 'luxon';

async function searchAvailability(eventTypeName, startDate, endDate, timezone) {
  // Step 1: Find event type by name
  const eventTypes = await calendly.getEventTypes();
  const eventType = eventTypes.find(et =>
    et.name.toLowerCase().includes(eventTypeName.toLowerCase())
  );

  if (!eventType) {
    throw new Error(`Event type "${eventTypeName}" not found`);
  }

  // Step 2: Fetch availability slots
  const availabilityResponse = await calendly.client.get(
    '/event_type_available_times',
    {
      params: {
        event_type: eventType.uri,
        start_time: DateTime.fromISO(startDate, { zone: timezone }).toISO(),
        end_time: DateTime.fromISO(endDate, { zone: timezone }).toISO()
      }
    }
  );

  // Step 3: Format slots for display
  const slots = availabilityResponse.data.collection.map(slot => {
    const dt = DateTime.fromISO(slot.start_time).setZone(timezone);
    return {
      start_time: slot.start_time,
      display_time: dt.toLocaleString(DateTime.DATETIME_MED),
      day_name: dt.toFormat('EEEE'),
      time_24h: dt.toFormat('HH:mm'),
      time_12h: dt.toFormat('h:mm a'),
      invitees_remaining: slot.invitees_remaining
    };
  });

  // Step 4: Group by day for widget display
  const slotsByDay = slots.reduce((acc, slot) => {
    const day = DateTime.fromISO(slot.start_time).setZone(timezone).toISODate();
    if (!acc[day]) acc[day] = [];
    acc[day].push(slot);
    return acc;
  }, {});

  return {
    event_type: eventType.name,
    duration: eventType.duration,
    slots_by_day: slotsByDay,
    total_slots: slots.length,
    timezone: timezone
  };
}

// Natural language time parsing helper
function parseTimePreference(naturalLanguage, timezone) {
  const now = DateTime.now().setZone(timezone);

  // Parse expressions like "next Tuesday afternoon"
  if (naturalLanguage.includes('next')) {
    const dayMatch = naturalLanguage.match(/(monday|tuesday|wednesday|thursday|friday|saturday|sunday)/i);
    if (dayMatch) {
      let targetDay = now.plus({ weeks: 1 }).set({ weekday: getDayNumber(dayMatch[1]) });

      if (naturalLanguage.includes('morning')) {
        return { start: targetDay.set({ hour: 8 }), end: targetDay.set({ hour: 12 }) };
      } else if (naturalLanguage.includes('afternoon')) {
        return { start: targetDay.set({ hour: 13 }), end: targetDay.set({ hour: 17 }) };
      }
    }
  }

  // Default: next 7 days, business hours
  return {
    start: now.set({ hour: 9 }),
    end: now.plus({ days: 7 }).set({ hour: 17 })
  };
}

function getDayNumber(dayName) {
  const days = { monday: 1, tuesday: 2, wednesday: 3, thursday: 4, friday: 5, saturday: 6, sunday: 7 };
  return days[dayName.toLowerCase()];
}

Advanced Features:

  • Smart parsing: Understands "early morning", "lunch hour", "end of week"
  • Team routing: Shows availability across multiple team members
  • Recurring slots: Handles weekly recurring availability patterns

Step 4: Booking Flow Implementation

Create a seamless booking experience with payment collection and confirmation automation.

// booking-flow.js - Complete booking creation with payment
import Stripe from 'stripe';
const stripe = new Stripe(process.env.STRIPE_SECRET_KEY);

async function createBooking({
  eventTypeUri,
  startTime,
  guestEmail,
  guestName,
  answers = [],
  requiresPayment = false,
  paymentAmount = 0
}) {
  // Step 1: Collect payment if required
  let paymentLink = null;
  if (requiresPayment && paymentAmount > 0) {
    const paymentSession = await stripe.paymentLinks.create({
      line_items: [
        {
          price_data: {
            currency: 'usd',
            product_data: {
              name: 'Consultation Deposit',
              description: `Appointment on ${DateTime.fromISO(startTime).toLocaleString(DateTime.DATETIME_MED)}`
            },
            unit_amount: paymentAmount * 100 // Convert to cents
          },
          quantity: 1
        }
      ],
      after_completion: {
        type: 'redirect',
        redirect: {
          url: 'https://yourwebsite.com/booking-confirmed'
        }
      },
      metadata: {
        guest_email: guestEmail,
        event_type: eventTypeUri,
        start_time: startTime
      }
    });

    paymentLink = paymentSession.url;
  }

  // Step 2: Create Calendly booking (after payment or if no payment required)
  const booking = await calendly.client.post('/scheduling_links', {
    max_event_count: 1,
    owner: eventTypeUri,
    owner_type: 'EventType'
  });

  const schedulingLink = booking.data.resource.booking_url;

  // Step 3: Pre-fill booking form with guest details
  const prefilledLink = `${schedulingLink}?email=${encodeURIComponent(guestEmail)}&name=${encodeURIComponent(guestName)}`;

  // Step 4: If intake form answers provided, map to custom fields
  const customAnswers = answers.map(a => ({
    question: a.question,
    answer: a.answer
  }));

  // Step 5: Send confirmation with next steps
  const confirmationData = {
    booking_link: prefilledLink,
    payment_link: paymentLink,
    guest_email: guestEmail,
    start_time: startTime,
    status: paymentLink ? 'pending_payment' : 'confirmed'
  };

  // Step 6: Store booking reference for later (webhook processing)
  await storeBookingReference(confirmationData);

  return {
    success: true,
    message: paymentLink
      ? `Payment required. Complete payment to confirm: ${paymentLink}`
      : `Booking confirmed! Calendar invite sent to ${guestEmail}`,
    booking_url: prefilledLink,
    payment_url: paymentLink,
    start_time: DateTime.fromISO(startTime).toLocaleString(DateTime.DATETIME_FULL)
  };
}

// Store booking for webhook correlation
async function storeBookingReference(bookingData) {
  // Store in database (Firestore, PostgreSQL, etc.)
  // Used to match webhook events with ChatGPT conversations
  console.log('Booking stored:', bookingData);
}

Step 5: Payment Processing Integration

Automate deposit collection and refund handling for professional services.

// payment-processor.js - Stripe payment automation
async function processBookingPayment(amount, description, customerEmail, metadata) {
  try {
    // Create Stripe Checkout Session for immediate payment
    const session = await stripe.checkout.sessions.create({
      payment_method_types: ['card'],
      line_items: [
        {
          price_data: {
            currency: 'usd',
            product_data: {
              name: description,
              description: 'Professional consultation session'
            },
            unit_amount: amount * 100
          },
          quantity: 1
        }
      ],
      mode: 'payment',
      success_url: 'https://yourwebsite.com/booking-success?session_id={CHECKOUT_SESSION_ID}',
      cancel_url: 'https://yourwebsite.com/booking-canceled',
      customer_email: customerEmail,
      metadata: metadata, // Store booking details
      payment_intent_data: {
        metadata: metadata
      }
    });

    return {
      payment_url: session.url,
      session_id: session.id
    };
  } catch (error) {
    throw new Error(`Payment processing failed: ${error.message}`);
  }
}

// Refund handling for cancellations
async function processRefund(paymentIntentId, amount, reason) {
  try {
    const refund = await stripe.refunds.create({
      payment_intent: paymentIntentId,
      amount: amount * 100, // Partial or full refund
      reason: reason || 'requested_by_customer',
      metadata: {
        refund_reason: reason,
        refund_date: new Date().toISOString()
      }
    });

    return {
      refund_id: refund.id,
      status: refund.status,
      amount_refunded: refund.amount / 100
    };
  } catch (error) {
    throw new Error(`Refund failed: ${error.message}`);
  }
}

// Webhook handler for payment events
async function handleStripeWebhook(event) {
  switch (event.type) {
    case 'checkout.session.completed':
      const session = event.data.object;
      // Confirm booking in Calendly after payment
      await confirmBookingAfterPayment(session.metadata);
      break;

    case 'charge.refunded':
      const charge = event.data.object;
      // Cancel Calendly booking after refund
      await cancelBookingAfterRefund(charge.metadata);
      break;
  }
}

Advanced Features

Intake Form Automation

Collect pre-call information conversationally instead of forcing clients to fill out forms:

// Calendly custom questions mapped from ChatGPT conversation
const intakeFormMapping = {
  "What's your main challenge?": "business_challenge",
  "What's your budget range?": "budget",
  "When do you want to start?": "timeline",
  "How did you hear about us?": "referral_source"
};

// ChatGPT extracts answers naturally during booking conversation
// Then maps to Calendly custom fields automatically

Pre-Call Questionnaires

Send targeted questions based on service type:

  • Coaching: Current situation, desired outcome, obstacles
  • Consulting: Business metrics, pain points, decision timeline
  • Therapy: Medical history, current concerns, insurance info
  • Legal: Case details, urgency, conflict check info

Follow-Up Automation

Sequence post-booking emails:

  • Immediate: Calendar invite + payment receipt
  • 24 hours before: Reminder with prep materials
  • 1 hour before: Meeting link + agenda
  • After call: Thank you + next steps

Meeting Prep Documents

Attach relevant materials based on conversation context:

  • Discovery call: Company overview, case studies
  • Strategy session: Pre-filled analysis templates
  • Coaching: Goal-setting worksheets

Widget Design for ChatGPT

Inline Card: Available Slots

<!-- availability-card.html -->
<div class="scheduling-card">
  <h3>Available Times - {{event_type_name}}</h3>
  <p class="duration">{{duration}} minutes • {{timezone}}</p>

  <div class="slots-container">
    {{#each slots_by_day}}
      <div class="day-section">
        <h4>{{day_name}} {{date}}</h4>
        <div class="time-slots">
          {{#each slots}}
            <button class="slot-button" onclick="selectSlot('{{start_time}}')">
              {{time_12h}}
            </button>
          {{/each}}
        </div>
      </div>
    {{/each}}
  </div>

  <p class="timezone-note">Times shown in {{timezone}}</p>
</div>

Fullscreen: Weekly Calendar View

For complex multi-day availability browsing:

  • Interactive weekly grid
  • Multiple service types side-by-side
  • Team member filtering
  • Time zone selector

Carousel: Service Types

Showcase different consultation offerings:

  • 15-min quick calls
  • 30-min discovery sessions
  • 60-min deep dives
  • Multi-session packages

Testing Your Scheduling App

Sandbox Mode Testing

  1. Create test event types in Calendly with short booking notice
  2. Use Stripe test mode for payment flows
  3. Test time zone conversions across multiple zones
  4. Verify webhook deliveries in Calendly dashboard

Critical Test Scenarios

  • Same-day booking: Ensure real-time availability updates
  • Payment failures: Graceful handling with retry options
  • Cancellation within policy window: Automated refunds
  • No-show handling: Automated follow-up sequences
  • Double-booking prevention: Optimistic locking on slots

Time Zone Validation

Test bookings from:

  • US Eastern (EST/EDT)
  • US Pacific (PST/PDT)
  • UK (GMT/BST)
  • Australia (AEST)
  • Asia (IST, JST)

Verify correct display and calendar event creation.

Marketing Your Scheduling ChatGPT App

Website Integration

Embed ChatGPT scheduling widget:

<script src="https://chatgpt.com/embed/your-scheduling-app.js"></script>
<div id="chatgpt-scheduler"></div>

Conversion benefits:

  • 24/7 availability (no business hours restriction)
  • Instant responses vs. form submissions
  • Higher booking completion rates

Social Media Strategy

LinkedIn: Share ChatGPT booking link in posts

"Book a strategy call through ChatGPT: chatgpt.com/g/your-scheduler"

Instagram: Bio link to ChatGPT scheduler Email signature: Direct link to AI booking assistant

Client Experience Enhancement

  • No app downloads: Works in ChatGPT web/mobile
  • Conversation history: Clients can reference past bookings
  • Rescheduling ease: "Reschedule my Tuesday call to Wednesday"
  • Payment transparency: See costs during booking conversation

Troubleshooting Common Issues

Calendar Sync Conflicts

Symptom: Double bookings or unavailable slots showing as available

Causes:

  • Calendar not synced to Calendly
  • Buffer time not configured
  • Multiple calendars not connected

Fix:

// Verify calendar connections
const calendarConnections = await calendly.client.get('/users/me/calendar_connections');
console.log('Connected calendars:', calendarConnections.data.collection);

// Check for conflicts
const conflicts = await calendly.client.get('/conflicts', {
  params: {
    start_time: startTime,
    end_time: endTime
  }
});

Payment Authorization Failures

Symptom: Stripe checkout fails or payment not captured

Causes:

  • Incorrect API keys (test vs. live)
  • Payment method restrictions
  • Amount formatting errors

Fix:

  • Verify Stripe API keys match environment
  • Check webhook signing secrets
  • Test with Stripe test cards first
  • Log full error responses for debugging

Time Zone Calculation Errors

Symptom: Appointments booked at wrong times

Causes:

  • Daylight saving time transitions
  • Incorrect IANA timezone identifiers
  • Server timezone vs. client timezone mismatch

Fix:

// Always use Luxon for timezone handling
import { DateTime } from 'luxon';

// CORRECT: Explicit timezone
const appointmentTime = DateTime.fromISO(inputTime, { zone: clientTimezone });

// WRONG: Assumes server timezone
const appointmentTime = new Date(inputTime); // ❌ Don't use Date()

Webhook Delivery Failures

Symptom: Booking confirmations not processed

Causes:

  • Webhook endpoint not HTTPS
  • Signature verification failing
  • Endpoint timing out (>30s response)

Fix:

  • Use ngrok for local testing: ngrok http 3000
  • Verify webhook signatures properly
  • Respond to webhooks within 5 seconds (process async)
  • Monitor Calendly webhook logs for failures

Conclusion

A professional scheduling ChatGPT app transforms how service professionals acquire and manage clients. By automating availability search, booking confirmation, payment collection, and calendar management, you eliminate scheduling friction that costs professionals 8-12 hours per week and causes 35-45% booking abandonment.

The implementation guide above provides production-ready code for:

  • ✅ Calendly/Acuity API integration with webhooks
  • ✅ Intelligent availability search with time zone handling
  • ✅ Seamless payment collection with Stripe
  • ✅ Automated intake forms and pre-call questionnaires
  • ✅ Follow-up email sequences and meeting prep

Next Steps:

  1. Deploy in 48 hours: Use MakeAIHQ's no-code platform to generate your scheduling MCP server without writing code
  2. Customize for your niche: Adapt intake forms, service types, and pricing for your specific professional service
  3. Market to 800M users: Publish to ChatGPT App Store and reach clients where they already work

Related Resources:

External Resources:

Ready to automate your professional scheduling and capture the ChatGPT market? Start building your scheduling ChatGPT app with MakeAIHQ — from zero to ChatGPT App Store in 48 hours, no coding required.

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