> ## Documentation Index > Fetch the complete documentation index at: https://docs.qxlabs.com/llms.txt > Use this file to discover all available pages before exploring further. # Triggers A trigger starts your flow when something happens in one of your apps. It goes first on the canvas, and a flow can have only one. Each needs a [credential](/connected-apps/overview) for the app it watches, plus whatever tells it what to look for. See [Schedules and triggers](/flows/schedules-and-triggers) for turning one on. * **Gmail Trigger** and **Outlook Mail Trigger** run your flow when an email arrives. Narrow it down by sender, recipient, or folder, so the flow only runs on the mail you care about. * **Google Sheets Trigger** runs when rows are added or changed in a spreadsheet. Pick the sheet and the columns you want, and only those columns are passed on. * **Google Calendar Trigger** and **Outlook Calendar Trigger** run when events are created, updated, or deleted. * **Slack Trigger** and **Teams Trigger** run when a message is posted in a channel you pick. Both can ignore messages from bots and pull in full threads. * **Salesforce Trigger** runs when records are created or updated, for the object type you choose. * **Custom Code Trigger** covers every other app, see [Custom code trigger](/flows/nodes/custom-code-trigger). A trigger hands its events on as lists, since one event can carry several items at once.