End of support notice: On October 7th, 2026, Amazon will discontinue support for Amazon IoT Greengrass Version 1. After October 7th, 2026, you will no longer be able to access the Amazon IoT Greengrass V1 resources. For more information, please visit [Migrate from Amazon IoT Greengrass Version 1](https://docs.amazonaws.cn/greengrass/v2/developerguide/migrate-from-v1.html).

# Module 3 (part 1): Lambda functions on Amazon IoT Greengrass
<a name="module3-I"></a>

This module shows you how to create and deploy a Lambda function that sends MQTT messages from your Amazon IoT Greengrass core device. The module describes Lambda function configurations, subscriptions used to allow MQTT messaging, and deployments to a core device.

[Module 3 (Part 2)](module3-II.md) covers the differences between on-demand and long-lived Lambda functions running on the Amazon IoT Greengrass core.

Before you begin, make sure that you have completed [Module 1](module1.md) and [Module 2](module2.md) and have a running Amazon IoT Greengrass core device.

**Tip**  
Or, to use a script that sets up your core device for you, see [Quick start: Greengrass device setup](quick-start.md). The script can also create and deploy the Lambda function used in this module.

This module should take about 30 minutes to complete.

**Topics**
+ [Create and package a Lambda function](create-lambda.md)
+ [Configure the Lambda function for Amazon IoT Greengrass](config-lambda.md)
+ [Deploy cloud configurations to a Greengrass core device](configs-core.md)
+ [Verify the Lambda function is running on the core device](lambda-check.md)