How to add a trigger to a function

Reviewed on April 23, 2025

This page shows you how to configure triggers for your Serverless Functions. A trigger is an event that invokes a function.

In a serverless architecture, a function only runs when it is called by an event. A trigger is a mechanism that connects the function to an event source and enables the function to run automatically in response to specific events.

A trigger can be an HTTP request, a message from a queue or stream, a CRON schedule etc. It is configured during the function deployment, and determines how and when the function will run.

Before you start

To complete the actions presented below, you must have:

• A Scaleway account logged into the console
• Owner status or IAM permissions allowing you to perform actions in the intended Organization
• Created a functions namespace
• Created a function
• Created credentials for Scaleway Queues
• Created a queue

Queue triggers

Queue triggers allow you to automatically invoke a function using events stored in a queue.

Only queues created with the Scaleway Queues product are compatible with Serverless Functions.

The configuration of the queue retention may affect the behavior of the trigger. Refer to the Considerations to configure event retention for queue trigger inputs page for more information.

1. Click Functions in the Serverless section of the side menu. The functions page displays.
2. Click the relevant functions namespace.
3. Click the name of the function you want to manage. The function Code tab displays.
4. Click the Triggers tab. The trigger configuration displays.
5. Click Create trigger. The trigger creation form displays in a pop-up.
6. Enter a name for your trigger and select the Queues (Scaleway) type, then select your queue name.
7. Click Create trigger to launch trigger creation.

NATS triggers

NATS triggers allow you to automatically invoke a function using messages sent in a NATS subject.

Scaleway NATS subjects are compatible with Serverless Functions.

1. Click Functions in the Serverless section of the side menu. The functions page displays.
2. Click the relevant functions namespace.
3. Click the name of the function you want to manage. The function Code tab displays.
4. Click the Triggers tab. The trigger configuration displays.
5. Click Create trigger. The trigger creation form displays in a pop-up.
6. Enter a name for your trigger and select the NATS (Scaleway) type, then select your NATS account and subject name.
7. Click Create trigger to launch trigger creation.

CRON triggers

CRON triggers allow you to invoke your functions based on a recurring schedule. The CRON triggers for Serverless Functions use the UTC time zone.

1. Click Functions in the Serverless section of the side menu. The functions page displays.
2. Click the relevant functions namespace.
3. Click the name of the function you want to manage. The function Code tab displays.
4. Click the Triggers tab. The trigger configuration displays.
5. Click Create trigger. The trigger creation form displays in a pop-up.
6. Enter a name for your trigger and select the CRON type.
7. Enter the cron schedule in UNIX format (* * * * *) and paste your JSON arguments in the form.
8. Click Create trigger to launch trigger creation.