Context configuration

In the client-side .NET SDK, you can construct a Context that only has a key by calling Context.New. The context kind defaults to "user," or you can supply a different context kind. Alternatively, you can use Context.Builder, which allows setting all properties.

The argument to Builder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the .NET (client-side) SDK, read Private attributes.

To learn how to configure anonymous contexts in the .NET (client-side) SDK, read Anonymous contexts and users.

In the Android SDK, use a builder pattern to construct contexts. The argument to builder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Android SDK, read Private attributes.

To learn how to configure anonymous contexts in the Android SDK, read Anonymous contexts and users.

In the C++ (client-side) SDK, you can construct a context using the ContextBuilder. The arguments to .Kind() are the context kind and key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key, an email address, or a hash for the key, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

To learn how to configure private attributes in the C++ (client-side) SDK, read Private attributes.

To learn how to configure anonymous contexts in the C++ (client-side) SDK, read Anonymous contexts and users.

Here's an example of a user:

The key property is the user's key. The key should uniquely identify each user. You can use a primary key or a hash, as long as the same user always has the same key. We recommend using a hash if possible. In this example, the hash is "user-key-123abc".

To learn how to configure private attributes in the Electron SDK, read Private attributes.

To learn how to configure anonymous users in the Electron SDK, read Anonymous contexts and users.

In the Flutter SDK, use a builder pattern to construct contexts. The arguments to LDContextBuilder are the context's kind and key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

To learn how to configure private attributes in the Flutter SDK, read Private attributes.

To learn how to configure anonymous contexts in the Flutter SDK, read Anonymous contexts and users.

In the iOS SDK, you can construct a context using LDContextBuilder. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

You can define additional attributes for a context by passing in a name and value for each. Additional attributes can be any JSON type, including boolean, number, string, array, or object.

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn more about the specific context properties that are available in this SDK, read LDContextBuilder.

To learn how to configure private attributes in the iOS SDK, read Private attributes.

To learn how to configure anonymous contexts in the iOS SDK, read Anonymous contexts and users.

In the JavaScript SDK, construct a context using key/value pairs for the context attributes. Contexts use the LDContext type. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example of a context:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the JavaScript SDK, read Private attributes.

To learn how to configure anonymous contexts in the JavaScript SDK, read Anonymous contexts and users.

In the Node.js (client-side) SDK, construct a context using key/value pairs for the context attributes. Contexts use the LDContext type. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example of a context:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

The kind and name attributes expect string values. Other attribute values can be booleans, numbers, strings, arrays, or JSON objects.

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Node.js (client-side) SDK, read Private attributes.

To learn how to configure anonymous contexts in the Node.js (client-side) SDK, read Anonymous contexts and users.

In the React Native SDK, construct a context using key/value pairs for the context attributes. Contexts use the LDContext type.

The first attribute in the object is the key. In the React Native SDK, both key and kind are required. They are the only mandatory attributes. The combination of key and kind must uniquely identify each context. You can use any value for the key, such as a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If the context is anonymous, you should set the key to an empty string. The SDK will automatically set the key to a LaunchDarkly-specific, device-unique string that is consistent between app restarts and device reboots.

Other attributes can be booleans, numbers, strings, arrays, or JSON objects.

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the React Native SDK, read Private attributes.

To learn how to configure anonymous contexts in the React Native SDK, read Anonymous contexts and users.

In the Roku SDK, use LaunchDarklyCreateContext to construct a context. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Roku SDK, read Private attributes.

To learn how to configure anonymous contexts in the Roku SDK, read Anonymous contexts and users.

In the server-side .NET SDK, you can construct a Context that only has a key by calling Context.New. The context kind defaults to "user," or you can supply a different context kind. Alternatively, you can use the Context.Builder method for building a context with other properties.

The argument to Builder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the .NET (server-side) SDK, read Private attributes.

To learn how to configure anonymous contexts in the .NET (server-side) SDK, read Anonymous contexts and users.

Here's an example of a user:

The argument to Builder is the user's key. The key should uniquely identify each user. You can use a primary key or a hash, as long as the same user always has the same key. We recommend using a hash if possible. In this example, the hash is "user-key-123abc".

To learn how to configure private attributes in the Apex SDK, read Private attributes.

To learn how to configure anonymous users in the Apex SDK, read Anonymous contexts and users.

In the C++ (server-side) SDK, you can construct a context using the ContextBuilder. The arguments to .Kind() are the context kind and key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash for the key, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If you are working in C, when you are done with the context ensure that you free the structure:

To learn how to configure private attributes in the C++ (server-side) SDK, read Private attributes.

To learn how to configure anonymous contexts in the C++ (server-side) SDK, read Anonymous contexts and users.

In the Erlang SDK, use ldclient_context:set and ldclient_context:new to define and construct a context.

The key property is the context's key. The key is the only mandatory context attribute. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

You can set the kind, or, if you do not set it, LaunchDarkly assumes that the context kind is "user."

Here's an example of a context:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

To learn how to configure private attributes in the Erlang SDK, read Private attributes.

To learn how to configure anonymous contexts in the Erlang SDK, read Anonymous contexts and users.

The Go SDK defines a Context struct and a Builder. The context key is the only mandatory context attribute. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

Each individual context within a multi-context can have the same attributes. The only restriction is that each context has to have a different context kind from the others within the multi-context.

You can also use the context builder to create each of the individual contexts:

To learn more about the available attributes, read Context and Builder.

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Go SDK, read Private attributes.

To learn how to configure anonymous contexts in the Go SDK, read Anonymous contexts and users.

In the Haskell SDK, use makeContext to create a new context. The argument to makeContext is the context's key. The key is the only mandatory attribute. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example of a context:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

To learn how to configure private attributes in the Haskell SDK, read Private attributes.

To learn how to configure anonymous contexts in the Haskell SDK, read Anonymous contexts and users.

In the Java SDK, use a builder pattern to construct contexts. The argument to Builder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

The documentation for ContextBuilder shows you all the attributes that LaunchDarkly supports by default.

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Java SDK, read Private attributes.

To learn how to configure anonymous contexts in the Java SDK, read Anonymous contexts and users.

In the Lua SDK, use makeContext to construct a context of any kind. This requires a context key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible. The context attributes are defined as part of the context kind.

To construct a user context specifically, you can use makeUser. Both makeUser and makeContext require a context key. You can omit the kind option if you construct your context with makeUser. This method is a convenience to make upgrading from the Lua SDK version 1.x to version 2.0 easier. It is deprecated and may be removed in future versions.

Here's an example of a context:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

To learn more, read makeUser and makeContext.

To learn how to configure private attributes in the Lua SDK, read Private attributes.

To learn how to configure anonymous contexts in the Lua SDK, read Anonymous contexts and users.

In the Node.js (server-side) SDK, contexts are JSON objects. The key property is the context key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Node.js (server-side) SDK, read Private attributes.

To learn how to configure anonymous contexts in the Node.js (server-side) SDK, read Anonymous contexts and users.

In the PHP SDK, use a builder pattern to construct contexts. The first argument to LDContextBuilder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

To learn how to configure private attributes in the PHP SDK, read Private attributes.

To learn how to configure anonymous contexts in the PHP SDK, read Anonymous contexts and users.

In version 8.0 and higher of the Python SDK, the Context class has a create method for creating a context with a context kind of "user" and with only a key. It has a builder method for building a context with other properties.

The argument to Context.builder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If you have many attributes to set, you can also create a context from a dictionary:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn more, read from_dict.

To learn how to configure private attributes in the Python SDK, read Private attributes.

To learn how to configure anonymous contexts in the Python SDK, read Anonymous contexts and users.

In the Ruby SDK, contexts are instances of LaunchDarkly::LDContext. Legacy users can continue to be provided as simple hashes.

The key property is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key, an email address, or a hash string, as long as the same context always has the same key. We recommend using a hash string if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Ruby SDK, read Private attributes.

To learn how to configure anonymous contexts in the Ruby SDK, read Anonymous contexts and users.

The Rust SDK defines a Context struct and a ContextBuilder.

The context key is the only mandatory context attribute. You can set the kind, or, if you do not set it, LaunchDarkly assumes that the context kind is "user." The combination of key and kind must uniquely identify each context. For the key, you can use a primary key, a hash string, or some other value, as long as the same context always has the same key. We recommend using a hash string if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

To learn more about the available attributes, read Context and ContextBuilder.

If an attribute is a JSON object, then in your flag or segment targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting. To learn more, read Target with flags.

To learn how to configure private attributes in the Rust SDK, read Private attributes.

To learn how to configure anonymous contexts in the Rust SDK, read Anonymous contexts and users.

To configure contexts, the Akamai SDK uses the same code as the Node.js server-side SDK.

The Akamai SDK does not support sending events, so private attributes are not supported.

To configure contexts, the Cloudflare SDK uses the same code as the Node.js server-side SDK.

To configure contexts, the Vercel SDK uses the same code as the Node.js server-side SDK.

In the .NET (AI) SDK, you can construct a Context that only has a key by calling Context.New. The context kind defaults to "user," or you can supply a different context kind. Alternatively, you can use the Context.Builder method for building a context with other properties.

The argument to Builder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your AI config targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting rules. You can use . as a delimiter in your AI config prompt. Continuing the same example, you could use {{ldctx.address.city}} in your prompt, and the value of the "city" field will be substituted when you customize the AI config. To learn more, read Target with flags and Customizing AI configs.

To learn how to configure private attributes in the .NET (AI) SDK, read Private attributes.

To learn how to configure anonymous contexts in the .NET (AI) SDK, read Anonymous contexts and users.

The Go (AI) SDK defines a Context struct and a Builder. The context key is the only mandatory context attribute. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

Each individual context within a multi-context can have the same attributes. The only restriction is that each context has to have a different context kind from the others within the multi-context.

You can also use the context builder to create each of the individual contexts:

If an attribute is a JSON object, then in your AI config targeting, you can use / as a delimiter to refer to specific object fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting rules. You can use . as a delimiter in your AI config prompt. Continuing the same example, you could use {{ldctx.address.city}} in your prompt, and the value of the "city" field will be substituted when you customize the AI config. To learn more, read Target with flags and Customizing AI configs.

To learn how to configure private attributes in the Go (AI) SDK, read Private attributes.

To learn how to configure anonymous contexts in the Go (AI) SDK, read Anonymous contexts and users.

In the Node.js (AI) SDK, contexts are JSON objects. The key property is the context key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If an attribute is a JSON object, then in your AI config targeting, you can use / as a delimiter to refer to specific fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting rules. You can use . as a delimiter in your AI config prompt. Continuing the same example, you could use {{ldctx.address.city}} in your prompt, and the value of the "city" field will be substituted when you customize the AI config. To learn more, read Target with AI configs and Customizing AI configs.

To learn how to configure private attributes in the Node.js (AI) SDK, read Private attributes.

To learn how to configure anonymous contexts in the Node.js (AI) SDK, read Anonymous contexts and users.

In the Python (AI) SDK, the Context class has a create method for creating a context with a context kind of "user" and with only a key. It has a builder method for building a context with other properties.

The argument to Context.builder is the context's key. The combination of key and kind must uniquely identify each context. For the key, you can use a primary key or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

Here's an example:

Here's how to construct a context with a context kind of something other than "user":

Here's how to construct a multi-context, which includes multiple context kinds:

If you have many attributes to set, you can also create a context from a dictionary:

If an attribute is a JSON object, then in your AI config targeting, you can use / as a delimiter to refer to specific fields. For example, if you have an "address" attribute that includes several fields, then you could use /address/city in your targeting rules. You can use . as a delimiter in your AI config prompt. Continuing the sam example, you could use {{LDCTX.address.city}} in your prompt, and the value of the "city" field will be substituted when you customize the AI config. To learn more, read Target with AI configs and Customizing AI configs.

To learn how to configure private attributes in the Python (AI) SDK, read Private attributes.

To learn how to configure anonymous contexts in the Python (AI) SDK, read Anonymous contexts and users.