Calendar provides tools for users to create, manage, and share
event and calendar details. Managing complex calendars can be time-consuming
when viewing, creating, updating, and sharing individual events, especially when
importing or exporting event information from other applications.

Save time and effort for your users by extending Calendar with
add-ons. When you build a Google Workspace add-on, you can
define interfaces inserted directly into Calendar, exactly where
the user needs them. These interfaces automate calendar tasks, present
additional information, or let the user interact with a third-party system
without switching browser tabs.

Add-ons can define the following kinds of extensions within
Calendar:

- Non-contextual [homepages](https://developers.google.com/workspace/add-ons/concepts/homepages).
- Contextual interfaces that appear when users click an event in the calendar view.
- Contextual interfaces that appear when users open an event to view or edit it.
- Custom [conferencing solutions](https://developers.google.com/workspace/add-ons/calendar/conferencing/overview#conference_solutions) for Calendar events (see [Third-party conferencing overview](https://developers.google.com/workspace/add-ons/calendar/conferencing/overview) for details).

Calendar add-ons aren't supported on mobile
clients.

## See what you can make

add-ons are built using
[Google Apps Script](https://developers.google.com/apps-script), and their interfaces defined using the
Apps Script
[Card service](https://developers.google.com/apps-script/reference/card-service). See
[Building add-ons](https://developers.google.com/workspace/add-ons/how-tos/building-workspace-addons)
for an overview. Add-on behavior is configured using a
[manifest](https://developers.google.com/workspace/add-ons/concepts/workspace-manifests), which includes
Calendar-specific sections.

When configuring your Google Workspace add-on to extend
Calendar, you must decide what interfaces to create and what
actions it can take. The following guides provide more information:

- [Building Calendar interfaces](https://developers.google.com/workspace/add-ons/calendar/building-calendar-interfaces)
- [Calendar actions](https://developers.google.com/workspace/add-ons/calendar/calendar-actions)
- [Manifests](https://developers.google.com/workspace/add-ons/concepts/workspace-manifests#manifest-structure)
- Try a sample:
  - [Plan travels with an AI agent accessible across Google Workspace](https://developers.google.com/workspace/add-ons/samples/travel-concierge)
  - [Build Gemini Enterprise agents that are tightly integrated with
    Google Workspace data stores, APIs, and
    add-ons](https://codelabs.developers.google.com/ge-gws-agents)
  - [Build Vertex AI agents that are tightly integrated with Workspace data
    stores, APIs, and
    add-ons](https://codelabs.developers.google.com/vertexai-gws-agents)

If you maintain a conferencing system, see
[Third-party conferencing overview](https://developers.google.com/workspace/add-ons/calendar/conferencing/overview)
for details on how to integrate your conference types within
Calendar.