Monitoring and handling errors in production

This guide describes how you can monitor and debug your functions in production.

Anchor to How it worksHow it works

Functions can fail by raising an exception, exceeding memory or time limits, or returning data that doesn't match the schema of the specific Function API. In other cases, the function can run successfully, but return unexpected results due to a bug in the function code.

To aid in debugging issues with a function, information about each function run is stored and made available through the Partner Dashboard. This includes metadata, such as when the run occurred and the shop that it was on, and function run details such as the function input and output.

Function run details are hidden by default for production shops because they can contain Personally Identifying Information (PII), unless they're shared by merchants. Merchants can share function run details by sharing an error report when the function fails or by sharing all function logs for an app.

Development shops are an exception and have all function run details visible.

Anchor to Sharing function run detailsSharing function run details

When a merchant shares function run details from the Shopify admin, you can access them from the app's Extensions section in your Partner Dashboard.

Anchor to Sharing an error reportSharing an error report

When a function is executed and an error occurs, a warning notification is displayed on the relevant page in the Shopify admin. For example, if you've executed a discount function, then the warning notification appears on the Discounts page.

The warning notification contains information about when errors started occurring. It also includes a link that enables users to share information with developers about function runs that failed.

1. From the Shopify admin, navigate to the page that's associated with the executed function.
2. Click the warning notification.
3. Click Share the error reports with <developer-name>.
4. Choose whether to include every time the customization ran within the last 24 hours.
5. Click Share.

An email notification is sent to the Partner organization's specified business contact.

Anchor to Share app function logsShare app function logs

Merchants can share all function run details for an app within the past 24 hours, whether there were function failures or not.

1. From the Shopify admin, navigate to the Apps and sales channels settings.
2. Select the app that you need to share function run details for.
3. Click the Share logs button in the Share function logs card.
4. Click the Share logs button in the modal.

An email notification is sent to the Partner organization's specified business contact.

Anchor to Debug a functionDebug a function

You can debug your function from the app's Extensions section in your Partner Dashboard.

1. From your Partner Dashboard, go to Apps.
2. Click the app that you deployed your function to.
3. Click Extensions.
4. Click the name of your function.

The function details page contains a list of function runs. After the merchant has consented to share function run details, you can inspect the details of each individual function run.

1. Input (STDIN): The JSON formatted input that you can copy to your clipboard. For illustrative purposes, the input in the screenshot has been omitted.

2. Output (STDOUT): Contains the output, if the function returned output

3. Logs (STDERR): Contains the STDERR logs of the function

4. Error message: Contains the final message sent to STDERR before the function failed

   Caution

   Function logs to STDERR are truncated after 1 kB. Some Wasm toolchains might crash if STDERR fails to write full logs.

Anchor to List of errorsList of errors

The following table provides a complete list of errors that can occur when running your function: