EOL NOTICE
From April 2022, we don't support the C SDK capability. For more details, see our Support Forum 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:
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.