## How triggers work

A trigger is a task in Shopify Flow that starts the execution of a workflow. The trigger represents an event that happens in a store or in an app. You can [build a trigger](/docs/apps/build/flow/triggers/create) for Shopify Flow so that events in your app trigger workflows to run.

![A diagram that show how third party triggers interface with Flow ](/assets/apps/flow/trigger_diagram.png)

## Next steps

- To build a trigger, you need to [create a trigger extension](/docs/apps/build/flow/triggers/create) in your app. In that extension, you specify details about the trigger using a [TOML file](/docs/apps/build/flow/triggers/reference).
- Once you have published your extension, you can then test or use it by [calling the Shopify API](/docs/apps/build/flow/triggers/reference#mutation-api-reference) with the trigger payload.