Use default or custom attributes (C SDK)

EOL NOTICE

As of April 2022, we're discontinuing support for several capabilities, including the C SDK. For more details, including how you can easily prepare for this transition, see our Explorers Hub post.

In New Relic, attributes are key-value pairs containing information that determines the properties of an event or transaction. These key-value pairs can help you gain greater insight into your application and query your data.

View and use attributes

Both default APM attributes and custom attributes for your C application appear in:

APM transaction traces and error analytics
APM events

C-specific attributes

Important

Before creating custom attributes, review New Relic's list of reserved terms used by NRQL. Otherwise unexpected results may occur.

To add custom attributes to your C application, call one of the attribute functions in the C SDK API; for example, newrelic_add_attribute_double(). The key name for your custom attribute depends on what you specify when you call the function.