This topic explains what context kinds are and how to use them. Context kinds let you group context attributes together conceptually. When you create individual targets or add targeting rules for a flag or a segment, the available context attributes are organized by context kind.
To learn how to create and manage context kinds, read Creating and editing context kinds and Archiving context kinds.
Contexts are people, services, machines, or other resources that encounter feature flags in your product.
Each context has one or more context kinds that you can use to categorize context instances for targeting and Experimentation.
The most common context kind is user. User contexts often include context attributes like name, email address, location, and so on. However, you can create other context kinds like organization or device. An organization context kind might include attributes like “name” or “address,” and a device context kind might include attributes like “type” or “operating system.”
Anna is a doctor who works for a hospital chain called Global Health Services. Anna has two mobile devices, an Android phone and an iPad tablet. Anna uses your application on both devices as part of her work.
We can describe the information about Anna using three different context kinds:
Here is an example of what the data structure for a user, an organization, and a device context object might look like, though each SDK sends context data to LaunchDarkly in a slightly different format:
When you create a new context kind, you provide only a name, key, and description. When your SDKs send a context object of that kind to LaunchDarkly, any attributes the SDK sends are automatically stored with the context.
You do not need to define any context attributes associated with a context kind when you create it. Instead, your SDK will send context attributes to LaunchDarkly along with the context object. To learn more, read Context attributes.
Context kinds are specific to LaunchDarkly projects. After you create them in a project, they are available in any of the environments within that project.
To learn how to create context kinds, read Creating and editing context kinds.
You can combine multiple contexts of different kinds together into a multi-context. Multi-contexts allow you to evaluate different, but related, contexts together.
For example, using multi-contexts a flag could target all doctors (a user context kind) using iPads (a device context kind) in Springfield (an organization context kind). To learn how, read Multi-contexts.
The only built-in default context kind is user. This is the context kind targeting rules use by default and, if you use Experimentation, the default randomization unit for experiments.
If you enable automatic environment attributes in a mobile SDK, the built-in context kinds ld_device and ld_application also become available after your SDK begins sending this information to LaunchDarkly. To learn how to enable automatic environment attributes, read Automatic environment attributes.
Each context has a key. Each combination of kind and key must be unique across all your contexts. Other context attributes can be strings, booleans, numbers, arrays, or JSON objects. When you evaluate a feature flag within your application, the flag’s targeting rules use information from one or more kinds of contexts. When you build your targeting rules, the attributes are automatically organized by context kind. To learn more, read Target with flags.
When you use the LaunchDarkly SDK to evaluate a flag, you provide an evaluation context to that call.
Configure your SDK: Context configuration, Evaluating flags
After different contexts encounter your application, you can view them on the Contexts list. To learn more, read The Contexts list.