Smart Links

A Smart Link is a single URL that creates a calendar event from the parameters you pass it. Wire it into a form, an email, a CRM, Zapier, or your own code, and events get created and synced to every major calendar automatically.

Create a Smart Link See the feature overview

How it works

Create a Smart Link in your dashboard and point it at a calendar. Each link has its own secret key. To create an event, visit the link with event details as URL parameters. AddCal creates the event, redirects to its public add-to-calendar page, and syncs it everywhere.

Smart Link URL

https://addcal.co/s/your-key
  ?title=Team+Meeting
  &date_start=2026-05-24T15:00:00
  &date_end=2026-05-24T16:00:00
  &timezone=America/New_York

Identical parameters always resolve to the same event, so a webhook firing twice or a refreshed link never creates a duplicate.

Parameters

Every event detail is passed as a URL parameter. Title and a start date are the only required fields.

Parameter	Required	Description
`title`	Required	The title of the event. A single line, up to 255 characters.
`date_start`	Required	Start date and time. Use ISO format like 2026-05-24T15:00:00. Avoid ambiguous formats like 1/2/2020.
`date_end`	Conditional	End date and time. Required unless you pass a duration or it is an all-day event.
`duration`	Conditional	Event length in minutes, for example 30 or 90. If both duration and date_end are set, date_end is ignored.
`timezone`	Optional	IANA timezone like America/New_York. Falls back to the calendar timezone if omitted.
`location`	Optional	A physical address or a virtual meeting link.
`description`	Optional	A longer description: agenda, notes, or instructions.
`is_all_day`	Optional	Use 1 for all-day events, 0 for time-specific. All-day events use the viewer's local timezone.

Either duration or date_end must be provided, unless the event is all-day.

Send straight to one calendar app

Add a calendar service to the end of the link to skip the chooser and send people directly to that calendar. Supported services: google, apple, outlook, outlook_web, office365, yahoo, ics.

Direct to Google Calendar

https://addcal.co/s/your-key/google?title=Team+Meeting&date_start=2026-05-24T15:00:00&duration=60

Merge fields, no code

Because a Smart Link is just a URL, you can build one in your email or CRM tool and drop its merge tags where the values go. Every recipient gets their own personalized event with nothing to build.

With merge tags

Mailchimp
https://addcal.co/s/your-key?title=*|EVENT_TITLE|*&date_start=*|EVENT_START|*

HubSpot
https://addcal.co/s/your-key?title={{event.title}}&date_start={{event.start}}

Approval workflow

Turn on approval for a Smart Link and incoming events arrive as pending. Nothing reaches your calendar until you review and approve it, so you can automate event creation without giving up control over what gets published.

Try it

Edit the details below and open your link. It runs on a shared demo Smart Link and really creates the event.

Try it, edit the details

Event title

Date

Start time

Duration (min)

Timezone

Your Smart Link

addcal.co/s/z2xrwph2pl?title=Onboarding+Call
  &date_start=2026-06-12T11%3A00%3A00
  &duration=30
  &timezone=America%2FLos_Angeles

Open the link, create the event

This is a live Smart Link on a shared demo calendar. Opening it really creates the event and lands you on its add-to-calendar page.

Limits

You can create as many Smart Links as you like on every plan. The free plan is for testing and caps the events created through Smart Links at 5 per month. Premium raises that to 200 events a month and Business is unlimited.