You can extend and customize Google Workspace Studio using Google Workspace add-ons. In addition to built-in Workspace actions, you can use custom add-ons to connect your flows to external tools and internal services:
- Custom starters: Begin an automated flow when a real-time event occurs in an external app or custom service (such as a new record in Airtable, an incoming webhook, or a customer support ticket update).
- Custom steps: Perform an action or task within the sequence of your flow (such as posting a message, creating a task, or sending an SMS).
On this page:
- Create custom starters & steps
- Install custom add-ons
- Use custom starters in flows
- Use custom steps in flows
- Manage account access for add-ons
- Related resources
Create custom starters & steps
You can build custom starters and steps using Google Apps Script or your preferred programming language with HTTP add-ons:
- In the add-on manifest, developers define starters using workflowTrigger and steps using workflowAction.
- Custom starters can notify Workspace Studio asynchronously whenever an event occurs by calling the Workspace Studio API endpoint.
- Developers can share custom add-ons privately with their team using test deployments, or publish them publicly to the Google Workspace Marketplace.
For detailed developer specifications, sample manifests, and API references, see:
- Build a starter (Google for Developers): https://developers.google.com/workspace/add-ons/studio/build-a-starter
- Build a step (Google for Developers): https://developers.google.com/workspace/add-ons/studio/build-a-step
Install custom add-ons
You can install add-ons that include custom starters, custom steps, or both:
Install from the Google Workspace Marketplace:
- Go to workspace.google.com/marketplace?host=workflow.
- This link takes you to a pre-filtered view of only add-ons and integrations that work with Workspace Studio.
- Select the add-on you want to install.
- Click Install.
- Follow the on-screen prompts to grant the add-on permission to access your Google Account data and complete installation.
Install a private test deployment from your developer: If a developer in your organization created a custom add-on that is not published to the Marketplace, they can share a test deployment ID with you:
- In Google Workspace, open your add-on management settings.
- Under "Developer add-ons," enter the Deployment ID provided by your developer.
- Click Install, then authorize the requested permissions.
Note: To uninstall an add-on, return to Google Workspace Marketplace, locate the add-on, and click Uninstall. If your administrator installed the add-on for your domain, only your administrator can uninstall it.
Use custom starters in flows
After installing an add-on that includes custom starters, the starters appear in the Workspace Studio flow editor.
- In Workspace Studio click Create flow.
- In the starter card at the beginning of the flow, click Add a starter.
- In the starter selection panel, locate the section for your installed add-on and select your custom starter.
- On the starter configuration card, configure any required input settings (such as entering a project identifier, selecting a resource filter, or signing into the external service).
- Add subsequent steps to your flow. The starter's output variables (such as event names, timestamps, or payload data) appear in the variable selector for downstream steps.
- When your flow is ready, click Turn on
.
How subscription lifecycle works
- Automatic subscription: When you turn on or publish a flow containing a custom starter, Workspace Studio automatically registers a subscription with the developer's add-on so it starts listening for events.
- Automatic un-subscription: When you turn off or delete the flow, Workspace Studio automatically notifies the developer's add-on to unsubscribe and stop sending future event notifications.
Note on testing: Workspace Studio does not support manual test runs for custom starters. To test your flow, turn the flow on and trigger a real event in the external app or service.
Use custom steps in flows
After you install a Workspace Studio add-on, the steps show up wherever you create and edit flows, including:.
- In the flow editor: In the step-selection panel, scroll to the section with the name of the add-on and click the custom step.
- With Gemini assistance: On the Studio Discover page, describe the flow you want to create in natural language. Studio can automatically suggest and place installed add-on steps.
Important: When you add variables to third-party integration steps or add-on steps, they might contain your Google Account data, such as the contents of an email in Gmail, a message in Google Chat, or an event in Calendar. The flow can then share this data with the third-party service. Make sure you trust the third-party service before running the flow.
Manage account access for add-ons
If you are concerned about an add-on's access to your Google Account data, you can view and remove its connections:
- Go to myaccount.google.com/connections.
- Search for the add-on in the list of third-party apps and services and select it.
- Click Delete all connections you have with [add-on name], then confirm.
Note: If you remove an add-on's account connection, flows that use its custom starters or steps might stop running. To reconnect the add-on, open the flow in Workspace Studio and re-authorize the connection when prompted.