Cal.com is an open-source appointment scheduling platform that allows individuals, teams, and organizations to easily manage online and in-person meetings. It offers customizable booking links, schedule coordination across multiple team members, two-way synchronization with external calendars, and native Stripe integration to collect payments at the time of booking.
You will be able to react to calendar events and execute operations on bookings directly from the conversation, managing the en tire lifecycle of an appointment without human intervention.
How to Connect Cal.com with Darwin AI
Before you begin, you must obtain your API key.
Log in to your Cal.com account.
Open the Settings section in the left-hand menu.
c. Click on API Keys and then Add.
d. Enter a name for your key, select an expiration date, and click Save.
e. Click Copy and then click Done.
Log in to Darwin, and go to Workflows > Apps in the main menu.
Click on Add a connection.
Select Cal.com > Add a connection.
Fill in the connection fields.
6. Click Continue. Your connection is ready!
Actions Your Agent Can Execute with Cal.com
Check availability: Show the client free time slots in real-time, taking into account individual or entire team schedules.
Schedule an appointment: Create the booking in Cal.com once the client chooses a time and, if applicable, makes the payment.
Reschedule an appointment: Change the date or time of an existing booking without losing the previous information.
Cancel an appointment: Free up the space in the schedule and, if applicable, initiate an automatic refund.
Confirm or reject bookings: Manually approve appointments that require validation or reject them if they do not meet the criteria.
Add attendees: Include other people in an already created meeting without needing to cancel it.
Mark as no-show: Record if a client did not show up for their appointment.
Note: Additionally, your agent can monitor Cal.com notifications (such as a cancellation or a completed appointment) to automatically send messages, surveys, or updates.
⚠️ Keep This in Mind Before Launching Your Automation
Test in a sandbox environment first: Run mock bookings, cancellations, and payments to verify that the entire flow works before exposing it to real clients.
Periodically check that the connection is active: If authentication with the Cal.com API expires, your AI agent will stop working. Regularly check that everything remains connected to avoid errors in client interactions.
Protect sensitive data: When managing payments and ID documents, make sure to comply with privacy regulations (GDPR, HIPAA) and store only essential data.
Grant only necessary permissions: Use the minimum OAuth scopes for the actions the agent will perform (for example,
BOOKING_WRITEonly if it creates or modifies bookings). This limits the risk in the event of an incident.API Limits: The API enforces a limit of 120 requests per minute for API Keys; if your agent handles a high volume, contact Cal.com support to increase this limit.
Industry-Specific Use Cases
To show you the potential of this integration beyond theory, here are practical examples applied to specific industries. Each reflects common problems that your AI agent can solve by combining the available actions in Cal.com. You can choose the one that best fits your reality and customize it as needed.
🏥 Health
Possible Flows:
Consultation with integrated payment and admission: Your AI agent can show the available times of the specialist the patient needs, retrieved in real-time from Cal.com. When the patient chooses a time, your agent will request payment and, once confirmed, will create the appointment in Cal.com. Next, if it's a new patient, it will create their profile in the medical software, either by asking for their details or sending a form for the client to fill out.
Smart cancellation management: If a patient asks to cancel their appointment, your AI agent will cancel the booking in Cal.com, free up the slot, and notify your team. If the cancellation is within the refund window, it will initiate the automatic refund. In the same WhatsApp message, it will offer the patient options to reschedule for another time.
Post-consultation follow-up: When the appointment ends at the scheduled time, your agent can generate the electronic invoice and send it via WhatsApp along with the medical prescription or post-treatment instructions, saving a copy in the medical record. It can also offer available dates for a follow-up consultation if the treatment requires it and send a brief satisfaction survey to evaluate the care received.
💡 Take Automation Further:
Post-consultation follow-up call: A few days after the appointment, your AI agent can make an automated call to ask how the patient is recovering. If they report discomfort or symptoms, it will offer to check availability and schedule a follow-up appointment instantly.
Segmentation by satisfaction: By storing the NPS (Net Promoter Score) in the patient's file, your agent can trigger automated campaigns based on the score: ask the most satisfied for reviews, send discounts to the dissatisfied to win them back, or include neutrals in loyalty campaigns.
🎓 Education
Possible Automations:
Class booking with integrated payment and access: When a student wants to book a class, your AI agent will check the availability of all teachers teaching that subject in Cal.com. After showing the options and receiving payment, it will create the booking. If it's a new student, it will create their profile on the e-learning platform and grant them access to the corresponding modules, either by requesting their details via WhatsApp or sending them a form.
Preparatory material and follow-up: Upon scheduling the tutoring session, your agent can automatically create a task in the teacher's tool to prepare the material and, 30 minutes before the class, send the student a WhatsApp reminder with the direct link to the virtual room.
Automatic certification upon package completion: When the last session of a package is delivered, your AI agent will detect that there are no more classes left and will generate a personalized digital certificate, sending it to the student via WhatsApp. It will also offer availability to continue with a new course, based on the one they already took and suggesting the next level or related topics.💡 Lleva la automatización más lejos
💡 Take Automation Further:
Teacher quality survey: At the end of each class, your agent can send a brief survey via WhatsApp to evaluate the teacher and the content. Depending on the score, it can trigger loyalty campaigns or discounts for future courses.
Staggered reminders to reduce absences: If a student does not confirm attendance, your agent can send progressive reminders (WhatsApp 24h before, 1h before, etc.) and, if they ultimately do not attend, offer them options to make up the class.
🏗️ Construction & Real Estate
Possible Automations:
Property tour with pre-verification and rescheduling: An interested party can book a property viewing. Your AI agent will ask them to upload an ID document to validate the booking. Once scheduled in Cal.com, your agent will send a unique temporary code via WhatsApp that will only work during the appointment time to access the property. If the client needs to change the date, your agent can reschedule the appointment, notify them of the new date and time, and automatically update the team's schedule. If the viewing ends without the real estate agent marking a sale, the lead will automatically enter a follow-up sequence with similar properties.
Post-tour follow-up: Your agent can contact the client a few days after the viewing to ask for their opinion on the property. If they showed interest, it will offer to schedule a second viewing or a meeting with a financial advisor.
Construction progress notifications: If you manage construction projects, your agent can send automated messages with photos and progress status every time a schedule milestone is completed, keeping investors informed without the architect having to write reports.
🚗 Car Sales
Possible Automations:
Test drive with real availability: When a client wants to test a specific model, your AI agent will check the sales advisors' availability in Cal.com and show the options. Once the appointment is confirmed, your agent will mark that vehicle as unavailable in the inventory, notify the team to prep it, and send the client a WhatsApp reminder with the dealership's location and a checklist of necessary documents.
No-show recovery: If the client does not attend the test drive, your AI agent can mark them as a no-show in Cal.com, tag them as "at risk" in the CRM, and automatically add them to a retargeting audience in Facebook Ads to target them with ads for the model they were interested in. It can also contact them via WhatsApp to offer a new date.
Immediate post-test commercial proposal: At the end of the appointment, your agent can generate a PDF proposal with the client's name, the tested model, and financing options, sending it via WhatsApp in minutes. If the client does not respond in the following days, your agent can do an automated follow-up to ask if they have questions or wish to schedule a second test.
💡 Take Automation Further:
Preventive maintenance: Your agent can check the vehicle's service history in the CRM and, if it detects that the service date is approaching, send the client a WhatsApp reminder offering to schedule the service appointment directly.
Post-sale follow-up: A few days after vehicle delivery, your agent can make a call or send an automated message to ask about their experience and, if the client is satisfied, ask for a review or invite them to recommend the dealership.