We’re enhancing the way you work with Google Workspace Add-ons in Gmail with the addition of Compose-time functions. Compose-time functions can help modify and format your messages in Gmail faster by: 

• Adding recipients in the “To”, “CC”, and “BCC” fields. 
• Inserting content into the subject line and body of the email. 
• Inserting message templates for a consistent look and feel for your communications, and more. 

Organizations can also create their own compose-time add-ons using Apps Script or alternative runtimes. Use the Google Workspace Developer Guide to learn more about building compose actions. 

• Admins: In the Admin Console, you can specify which applications your users can install from the Google Workspace Marketplace. You can also install chosen Google Workspace Add-ons for your entire domain via the listing in the Google Workspace Marketplace. 
• End users: If allowed by your admin, you’ll be able to install Google Workspace Add-ons using the “+” button in the Google Workspace quick access side panel. The add-ons you install will appear in the side panel across Google Workplace apps. 

• Compose time add-ons are available now in the Google Workspace Marketplace. 

• Available to all Google Workspace customers (when enabled by admins) and users with personal accounts.  

• Google Workspace Admin Help: Allowlist Workspace Marketplace apps 
• Google Workspace Developer: Extending the compose UI with compose actions 
• Google Help: Use Google products side by side 
• Google Workspace Marketplace