User and context configuration

In the client-side .NET SDK, you can construct a simple Context, with a context kind of "user", that only has a key by calling Context.New. Alternatively, you can use Context.Builder, which allows setting all properties.

Here's an example:

Context context = Context.Builder("context-key-123abc")
    .Set("firstName", "Sandy")
    .Set("lastName", "Smith")
    .Set("email", "sandy@example.com")
    .Set("group", "microsoft")
    .Build();
COPY

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

Private attributes in the client-side .NET SDK

You can optionally configure the client-side .NET SDK to treat some or all attributes as private attributes. Private attributes can be used for targeting purposes, but are removed from the data sent back to LaunchDarkly.

In the client-side .NET SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• When creating the LaunchDarkly Configuration object, you can call the AllAttributesPrivate method, which takes in a boolean parameter. If true, all context attributes except the kind and key for all contexts are removed before the SDK sends the context to LaunchDarkly.
• When creating the LaunchDarkly Configuration object, you can call the PrivateAttributes method, which takes any number of attribute names or slash-delimited paths to designated a JSON property within an attribute, such as /address/street. If any context has a custom or built-in attribute that matches one of these names, the SDK removes it before sending the context to LaunchDarkly.

You can also mark attributes as private when building the context object by calling Private() on the context builder.

For example:

var context = Context.Builder("context-key-123abc")
    .Set("email", "sandy@example.com")
    .Private("email")
    .Build();
COPY

When the SDK sends this context back to LaunchDarkly, it removes the email attribute.

Anonymous contexts in the client-side .NET SDK

You can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

Context context = Context.Builder("context-key-123abc")
    .Anonymous(true)
    .Build();
COPY

You still need to generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

If you don't use Experimentation, we recommend using the same context key for every initialization and then replacing that with the actual context key when you know who the end user is. This way LaunchDarkly counts the initialization context key only once against your MAU, instead of every time you initialize.

Here's how:

Configuration config = Configuration.Builder("mobile-key-123abc")
    .GenerateAnonymousKeys(true)
    .Build();
COPY

If you set this option, the SDK will generate a key for any context whose anonymous attribute is true. You must still specify a non-null key as a placeholder when you construct the Context, because the SDK does not allow a Context to exist with a null key. When you pass this context to SDK methods like Init or Identify, the SDK replaces the placeholder key with a generated key.

In this example, the placeholder key is "unknown-context-key", but it could be any non-empty string:

Context context = Context.Builder("unknown-context-key")
    .Anonymous(true)
    .Build();
COPY

In the Android SDK, use a builder pattern to construct contexts.

Here's an example:

LDContext context = LDContext.builder("context-key-123abc")
    .set("email", "sandy@example.com")
    .set("firstName", "Sandy")
    .set("lastName", "Smith")
    .set("group", "Microsoft")
    .build();
COPY

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

Private attributes in the Android SDK

You can optionally configure the Android SDK to treat some or all attributes as private context attributes. Private attributes can be used for targeting purposes, but are removed from the context data sent back to LaunchDarkly.

In the Android SDK you can define private attributes for the entire LaunchDarkly client. When creating the LDConfig object, call the privateAttributes method, which takes in a set of custom or built-in attributes as a parameter. If any context has a custom or built-in attribute named in this set, the SDK removes it before sending the context to LaunchDarkly.

Here's how to configure private attributes:

LDConfig ldConfig = new LDConfig.Builder()
    .events(
        Components.sendEvents()
            .privateAttributes("name", "group")
    )
    .build();
COPY

You can also mark attributes as private when building the context object by using the private versions of the builder methods to set the attributes. For example:

LDContext context = LDContext.builder("context-key-123abc")
    .set("email", "sandy@example.com")
    .set("name", "Sandy")
    .set("group", "Microsoft")
    .privateAttributes("name", "group")
COPY

When the SDK sends this context back to LaunchDarkly, it removes the name and group attributes.

Anonymous users in the Android SDK

You can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

LDContext context = LDContext.builder("context-key-123abc")
    .anonymous(true)
    .build();
COPY

You can leave the key parameter in the Builder null or make it an empty string. The client will automatically set it to a LaunchDarkly-specific, device-unique string that is consistent between app restarts and device reboots.

If you don't use Experimentation, we recommend using the same context key for every initialization and then replacing that with the actual context key when you know who the end user is. This way LaunchDarkly counts the initialization context key only once against your MAU, instead of every time you initialize.

In the C/C++ (client-side) SDK, you can construct a user using LDUserNew.

Here's an example:

struct LDJSON *attributes, *groups;
groups = LDNewArray();
LDArrayPush(groups, LDNewText("Google"));
LDArrayPush(groups, LDNewText("Microsoft"));
attributes = LDNewObject();
LDObjectSetKey("groups", groups);
struct LDUser *user = LDUserNew("user-key-123abc");
LDUserSetFirstName(user, "Sandy");
LDUserSetLastName(user, "Smith");
LDUserSetCustomAttributesJSON(user, attributes);
COPY

The argument to LDUserNew is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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".

Private user attributes in the C/C++ SDK

You can optionally configure the C/C++ SDK to treat some or all user attributes as private user attributes. Private user attributes can be used for targeting purposes, but are removed from the user data sent back to LaunchDarkly.

In the C/C++ SDK there are two ways to define private attributes for the LaunchDarkly client:

• When creating the LDConfig object, you can set the allAttributesPrivate value to true. When you do this, all user attributes except the key are removed before the SDK sends the user to LaunchDarkly.
• When creating the LDConfig object, you can configure a map of privateAttributeNames. If any user has a custom or built-in attribute named in this list, the SDK removes it before sending the user to LaunchDarkly.

struct LDConfig *config = LDConfigNew("mobile-key-123abc");
// Mark all attributes private
LDConfigSetAllAttributesPrivate(config, true);
COPY

Anonymous users in the C/C++ SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

struct LDUser *user = LDUserNew("user-key-123abc");
LDUserSetAnonymous(user, true);
COPY

If you don't use Experimentation, we recommend using the same user key for every initialization and then replacing that with the actual user key when you know who the user is. This way LaunchDarkly counts the initialization user key only once against your MAU, instead of every time you initialize.

Here's an example of a user:

const user = {
  key: 'user-key-123abc',
  firstName: 'Sandy',
  lastName: 'Smith',
  email: 'sandy@example.com',
  custom: {
    groups: ['Google', 'Microsoft']
  }
};
COPY

The key property is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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".

Private user attributes in the Electron SDK

You can optionally configure the SDK to treat all user attributes as private user attributes. Private user attributes can be used for targeting purposes, but the SDK removes them from the user data sent back to LaunchDarkly.

To mark all user attributes except the key as private, you can use the allAttributesPrivate option:

const user = {
  key: 'user-key-123abc',
  name: 'Sandy Smith',
  email: 'sandy@example.com'
};
const client = LDElectron.initialize('client-side-id-123abc', user, {
  allAttributesPrivate: true
});
COPY

In the above example, the SDK removes the name and email attributes.

You can also specify an array of which attributes should be private with the privateAttributeNames option. You can configure this option on a per-user basis by specifying which attributes should be private in your user object.

This option is configured in both the user object and the configuration object:

const user = {
  key: 'user-key-123abc',
  name: 'Sandy Smith',
  email: 'sandy@example.com',
  privateAttributeNames: ['email']
};
const client = LDElectron.initialize('client-side-id-123abc', user, {
  privateAttributeNames: ['email']
});
COPY

In the above example, the SDK sends only the key and name back to LaunchDarkly.

Anonymous users in the Electron SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

// To create an anonymous user with an auto-generated key, specify
// the "anonymous" property and omit the "key" property. The LaunchDarkly
// client creates a unique key for this user and caches it locally.
const anonymousUser = { anonymous: true };
// You can also specify any key you want:
const anonymousUser2 = { key: 'user-key-123abc', anonymous: true };
COPY

If you don't use Experimentation, we recommend using the same user key for every initialization and then replacing that with the actual user key when you know who the user is. This way LaunchDarkly counts the initialization user key only once against your MAU, instead of every time you initialize.

In the Flutter SDK, use a builder pattern to construct users.

Here's an example:

LDUser user = LDUserBuilder('user-key-123abc')
    .email('sandy@example.com')
    .firstName('Sandy')
    .lastName('Smith')
    .custom('group', LDValue.ofString('microsoft'))
    .build();
COPY

The argument to LDUserBuilder is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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".

Private user attributes in the Flutter SDK

Optionally, you can configure the Flutter SDK to treat some or all user attributes as private user attributes. You can use private user attributes for targeting purposes. They are removed from the user data sent back to LaunchDarkly.

In the Flutter SDK, you can define private attributes for the entire LaunchDarkly client. When you create the LDConfig object, you can call the privateAttributeNames method, which takes in a set of custom or built-in attributes as a parameter. If any user has a custom or built-in attribute named in this set, the SDK removes it before sending the user to LaunchDarkly.

Set<String> privateAttributes =
  { 'name' // built-in attribute
  , 'group' // custom attribute
  };
LDConfig ldConfig = new LDConfigBuilder()
    .privateAttributeNames(privateAttributes)
    .build();
COPY

You can also mark attributes as private when building the user object by using the private versions of the builder methods to set the attributes. For example:

LDUser user = LDUserBuilder('user-key-123abc')
    .email('sandy@example.com')
    .privateName('Jane')
    .privateCustom('group', LDValue.ofString('microsoft'))
    .build();
COPY

When the SDK sends this user back to LaunchDarkly, the name and group attributes are removed.

Anonymous users in the Flutter SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

LDUser user = LDUserBuilder('user key')
    .anonymous(true)
    .build();
COPY

If you don't use Experimentation, we recommend using the same user key for every initialization and then replacing that with the actual user key when you know who the user is. This way LaunchDarkly counts the initialization user key only once against your MAU, instead of every time you initialize.

You can pass optional properties to the context object in iOS:

var contextBuilder = LDContextBuilder(key: "user-key-123abc")
contextBuilder.trySetValue("name", .string("Sandy"))
contextBuilder.trySetValue("email", .string("sandy@example.com"))
let context = try contextBuilder.build().get()
COPY

This example sets a key and adds the end user's full name and email address.

The key property should uniquely identify each context. 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 Targeting with flags.

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

Private attributes in the iOS SDK

You can optionally configure the iOS SDK to treat some or all context attributes as private attributes. Private attributes can be used for targeting purposes, but are removed from the context data the SDK sends to LaunchDarkly.

In the iOS SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• When creating the LDConfig object, you can set the allContextAttributesPrivate attribute to true.
• When creating the LDConfig object, you can set the privateContextAttributes property to a list of References, such as [Reference("name"), Reference("/address/state")]. If any context has a custom or built-in attribute named in this list, the SDK removes it before sending the context to LaunchDarkly.

You can also mark attributes as private on a particular LDContext instance, for example:

var contextBuilder = LDContextBuilder(key: "context-key-123abc")
contextBuilder.trySetValue("name", .string("Sandy"))
contextBuilder.trySetValue("group", .array([LDValue(stringLiteral: "microsoft")]))
contextBuilder.addPrivateAttribute(Reference("name"))
contextBuilder.addPrivateAttribute(Reference("group"))
let context = try contextBuilder.build().get()
COPY

Anonymous contexts in the iOS SDK

You can declare an LDcontext to be an anonymous, not logged-in end user:

var contextBuilder = LDContextBuilder(key: "context-key-123abc")
contextBuilder.anonymous(true)
let context = contextBuilder.build().get()
// Or have the SDK use a device persistent key. This sets `isAnonymous` by default.
let context = try LDContextBuilder().build().get()
COPY

You must generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

If you don't use Experimentation, we recommend using the same context key for every initialization and then replacing that with the actual context key when you know who the context is. This way LaunchDarkly counts the initialization context key only once against your MAU, instead of every time you initialize.

Here's an example of a context:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  firstName: 'Sandy',
  lastName: 'Smith',
  email: 'sandy@example.com',
  groups: ['Google', 'Microsoft']
};
COPY

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

The optional name and kind attributes expect string values. If the kind attribute is not specified, it is assumed to be "user." 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 Targeting with flags.

Private attributes in the JavaScript SDK

You can optionally configure the JavaScript SDK to treat all attributes as private context attributes. Private attributes can be used for targeting purposes, but are removed from the context data sent back to LaunchDarkly.

To mark all attributes except the key as private in the JavaScript SDK, you can use the allAttributesPrivate option:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  name: 'Sandy Smith',
  email: 'sandy@example.com'
};
const ldclient = ld.initialize('client-side-id-123abc', context, options = {
  allAttributesPrivate: true
});
COPY

In the above example, the name and email attributes are removed.

You can configure this option either in the context object or in the configuration object, by specifying an array of attributes that should be private. In the context object, specify your array of attributes in the privateNames field of the reserved _meta property. In the configuration object, specify your array of attributes in the privateAttributes configuration option.

Here's how:

const context = {
  kind: 'user',
  key: 'context-key-123abc',
  name: 'Sandy Smith',
  email: 'sandy@example.com',
  _meta: {
    privateAttributes: ['email']
  }
};
const ldclient = ld.initialize('client-side-id-123abc', context, options = {
  privateAttributes: ['email']
});
COPY

In the above example, the SDK sends only the context's key and name back to LaunchDarkly.

Anonymous contexts in the JavaScript SDK

You can distinguish logged-in end users from anonymous end users in the SDK.

If you use multi-contexts, you can choose to make only some contexts anonymous.

Here's how:

// To create an anonymous context, specify the "anonymous" property and
// omit the "key" property. In doing so, the LaunchDarkly client
// auto-generates a unique identifier for this context. The
// identifier is saved in local storage and reused in future
// browser sessions to ensure a constant experience.
const anonymousUserContext = {
  kind: 'user',
  anonymous: true
};
// A multi-context can contain both anonymous and non-anonymous contexts.
// Here, the organization is not anonymous.
const multiContext = {
  kind: 'multi',
  user: anonymousUserContext,
  org: {
    key: 'org-key',
    name: 'Example organization name'
  }
}
COPY

If you don't use Experimentation, we recommend using the same context key for every initialization and then replacing that with the actual context key when you know who the logged-in end user is. This way LaunchDarkly counts the initialization context key only once against your MAU, instead of every time you initialize.

Here's an example of a user:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  firstName: 'Sandy',
  lastName: 'Smith',
  email: 'sandy@example.com',
  custom: {
    groups: ['Google', 'Microsoft']
  }
};
COPY

The key property is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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".

Private attributes in the Node.js SDK

You can optionally configure the SDK to treat all user attributes as private user attributes. Private user attributes can be used for targeting purposes, but are removed from the user data sent back to LaunchDarkly.

To mark all user attributes except the key as private in the JavaScript SDK, you can use the allAttributesPrivate option:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  name: 'Sandy Smith',
  email: 'sandy@example.com'
};
const client = ld.initialize('client-side-id-123abc', context, {
  allAttributesPrivate: true
});
COPY

In the above example, the name and email attributes are removed.

You can also specify an array of which attributes should be private with the privateAttributes option. You can configure this option on a per-context basis by specifying which attributes should be private in your context object.

You can configure this option in both the context object and the configuration object:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  name: 'Sandy Smith',
  email: 'sandy@example.com'
  _meta: {
    privateAttributes: ['email']
  }
};
const client = ld.initialize('client-side-id-123abc', context, {
  privateAttributes: ['email']
});
COPY

In the above example, the SDK sends only the user's key and name back to LaunchDarkly.

Anonymous contexts in the Node.js SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

// To create an anonymous user with an auto-generated key, specify
// the "anonymous" property and omit the "key" property. The LaunchDarkly
// client creates a unique key for this user and caches it locally.
const anonymousContext = { kind: 'user', anonymous: true };
// You can also specify any key you want:
const anonymousContext2 = { kind: 'user', key: "user-key-123abc", anonymous: true };
COPY

If you don't use Experimentation, we recommend using the same context key for every initialization and then replacing that with the actual context key when you know who the user is. This way LaunchDarkly counts the initialization context key only once against your MAU, instead of every time you initialize.

Here is a context configuration object:

// key and kind are the only required attributes
let context = {
  key: 'user-key-123abc',
  kind: 'user',
  firstName: 'Sandy',
  lastName: 'Smith',
  email: 'sandy@example.com',
  address: {
    street: '123 Main St',
    city: 'Springfield'
  }
};
COPY

The first attribute in the object is the key. In the example, the value is user-key-123abc. key and kind are the only mandatory attributes. The combination of key and kind should also uniquely identify each context. You can use any value such as a primary key, an email address, or a hash, as long as the same context always has the same key. We recommend using a hash if possible.

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 Targeting with flags.

Private attributes in the React Native SDK

You can optionally configure the React Native SDK to treat attributes as private context attributes. Private attributes can be used for targeting purposes, but are removed from the context data sent back to LaunchDarkly.

You can configure this option in the configuration object, to apply to all contexts, either for all attributes or some attributes. Here's how:

const config = {
  mobileKey: 'mobile-key-123abc',
  allAttributesPrivate: true
};
await ldClient.configure(config, context);
COPY

To learn more, read allAttributesPrivate and privateAttributes on LDConfig.

You can also mark an attribute as private for a particular context. Here's how:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  firstName: 'Sandy',
  lastName: 'Smith',
  email: 'sandy@example.com',
  address: {
    street: '123 Main St',
    city: 'Springfield'
  },
  _meta: {
    privateAttributes: ['email', '/address/street']
  }
};
COPY

For attributes that are objects, you can mark specific fields private, using the / delimiter followed by the attribute name, then the / delimiter followed by the JSON property within the value. In the example, the attribute "address": { "street": "Main St", "city": "Springfield" } has only the /address/street marked as private.

Anonymous contexts in the React Native SDK

You can distinguish logged out or unregistered end users from logged-in end users in the SDK. Anonymous contexts are just like regular contexts, except that they do not appear on the Contexts list in LaunchDarkly. This prevents unauthenticated end users from diluting useful data on the Contexts list.

If you omit the context key when building an anonymous context, the SDK sets the context key to a generated UUID. If you omit the context key and do not mark the context as anonymous, the SDK gives a usage error.

If you use multi-contexts, you can choose to make only some contexts anonymous.

Here's how:

// This user context is not anonymous
const userContext = {
  kind: 'user',
  key: 'user-key-123abc'
}
// This device context is anonymous
// The key is omitted, and the SDK will automatically generate one
const deviceContext = {
  kind: 'device',
  deviceId: '12345',
  anonymous: true
}
// The multi-context contains one anonymous context
// and one non-anonymous context
const multiContext = {
  kind: 'multi',
  user: userContext,
  device: deviceContext
}
COPY

We recommend using the same context key for every initialization and then replacing that with the actual context key when you know who the logged-in end user is. This way LaunchDarkly counts the initialization user key only once against your MAU, instead of every time you initialize.

You can create a user object with:

user = LaunchDarklyUser("user-key-123abc")
COPY

User objects can be customized with:

user.setFirstName(String)
user.setLastName(String)
user.setEmail(String)
user.setName(String)
user.setAvatar(String)
user.setCustom(AssociativeArray)
COPY

Private user attributes in the Roku SDK

Users can have specific fields marked as private with:

user.addPrivateAttribute(String)
COPY

Anonymous users in the Roku SDK

Designate an anonymous user with:

user.setAnonymous(Boolean)
COPY

In the .NET SDK, the Context class has a New method for creating a simple context, with a context kind of "user" and with only a key. It has a Builder method for building a context with other properties.

Here's an example:

LDContext context = Context.Builder("context-key-123abc")
    .Set("firstName", "Sandy")
    .Set("lastName", "Smith")
    .Set("email", "sandy@example.com")
    .Set("groups", LdValue.ArrayOf(LdValue.Of("Google"), LdValue.Of("Microsoft")))
    .Build();
COPY

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

Private attributes in the .NET SDK

You can optionally configure the .NET SDK to treat some or all context attributes as private attributes. You can use private context attributes for targeting purposes, but the SDK removes private context attributes from the data it sends to LaunchDarkly.

In the server-side .NET SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• When creating the LaunchDarkly Configuration object, you can configure Events with AllAttributesPrivate, which takes in a boolean parameter. If true, the SDK removes all attributes for all contexts before sending the context to LaunchDarkly, except the key.
• Or, you can configure Events with PrivateAttributes, which takes any number of attribute names or slash-delimited paths to designated a JSON property within an attribute, such as /address/street. If any context has a custom or built-in attribute that matches one of these names, the SDK removes it before sending the context to LaunchDarkly.

You can also mark attributes as private when building the context object by calling Private() after setting the attribute on the context builder.

For example:

var context = Context.Builder("context-key-123abc")
    .Set("email", "sandy@example.com")
    .Private("email")
    .Build();
COPY

When the SDK sends this context back to LaunchDarkly, it removes the email attribute.

Anonymous contexts in the .NET SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

var context = Context.Builder("context-key-123abc")
    .Anonymous(true)
    .Build();
COPY

You still need to generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

Here's an example of a user:

LDUser user = new LDUser.Builder('user-key-123abc')
    .setFirstName('Sandy')
    .setLastName('Smith')
    .setEmail('sandy@example.com')
    .setCustom(new LDValueObject.Builder()
        .set('groups', new LDValueArray.Builder()
            .add(LDValue.of('Google'))
            .add(LDValue.of('Microsoft'))
            .build()
        )
        .build()
    )
    .build();
COPY

The argument to Builder is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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".

Anonymous users in the Apex SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

LDUser user = new LDUser.Builder('abc123')
    .setAnonymous(true)
    .build();
COPY

You still need to generate a unique key for anonymous users. Session IDs or UUIDs work best for this.

Private user attributes in the Apex SDK

Optionally, you can configure the Apex SDK to treat some or all user attributes as private user attributes. You can use private user attributes for targeting, but they are redacted from the user data sent back to LaunchDarkly.

In the Apex SDK there are two ways to define private attributes for the LaunchDarkly client:

• When creating the LDConfig object, you can use setAllAttributesPrivate(true). When you do this, all user attributes, except the key, are redacted before the SDK sends the user to LaunchDarkly.

  Here's how:

  Java

  LDConfig config = new LDConfig.Builder()
      .setAllAttributesPrivate(true)
      .build();
  COPY

• You can also define private attribute names on a per-user basis.

  Here's how:

  Java

  Set<String> privateAttributes = new Set<String>();
  privateAttributes.add('firstName');
  LDUser user = new LDUser.Builder('user-key-123abc')
      .setFirstName('alice')
      .setPrivateAttributeNames(privateAttributes)
      .build();
  COPY

Here's an example of a user:

struct LDUser *user = LDUserNew("user-key-123abc");
LDUserSetFirstName(user, "Sandy");
LDUserSetLastName(user, "Smith");
LDUserSetEmail(user, "sandy@example.com");
struct LDJSON *tmp;
struct LDJSON *custom = LDNewObject();
struct LDJSON *groups = LDNewArray();
tmp = LDNewText("Google");
LDArrayPush(groups, tmp);
tmp = LDNewText("Microsoft");
LDArrayPush(groups, tmp);
LDObjectSetKey(custom, "groups", groups);
LDUserSetCustom(user, custom);
COPY

The argument to LDUserNew is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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".

LDUserFree(user);
COPY

When you are done with an LDUser ensure that you free the structure.

Private user attributes in the C/C++ SDK

You can optionally configure the C/C++ SDK to treat some or all user attributes as private user attributes. Private user attributes can be used for targeting purposes, but are removed from the user data sent back to LaunchDarkly.

In the C/C++ SDK there are three ways to define private attributes for the LaunchDarkly client:

• When creating the LDConfig object, you can use LDConfigSetAllAttributesPrivate. When you do this, all user attributes (except the key) for the user are removed before the SDK sends the user to LaunchDarkly.

For example:

LDConfigSetAllAttributesPrivate(config, true);
COPY

• When creating the LDConfig object, you can list specific private attributes with LDConfigAddPrivateAttribute. If any user has a custom or built-in attribute named in this list, the SDK removes it before sending the user to LaunchDarkly.

LDConfigAddPrivateAttribute(config, "email");
COPY

• You can also define private attribute names on a per-user basis. For example:

LDUserAddPrivateAttribute(user, "email");
COPY

Anonymous users in the C/C++ SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

LDUserSetAnonymous(user, true);
COPY

You still need to generate a unique key for anonymous users. Session IDs or UUIDs work best for this.

Here's an example of a context:

Context = ldclient_context:set(<<"name">>, <<"Sandy Smith">>,
        ldclient_context:set(<<"email">>, <<"sandy@example.com">>,
        ldclient_context:set(<<"group">>, [<<"microsoft">>, <<"google">>],
        ldclient_context:new(<<"user-key">>, <<"user">>)))),
COPY

The key property is the context's key. The key is the only mandatory context attribute. The combination of key and kind should uniquely identify each context. You can set the kind, or, if you do not set it, LaunchDarkly assumes that the context kind is "user". You can use a primary key, an email address, or a hash, as long as the same context always has the same key. We recommend using a hash if possible. In this example the hash is "user-key-123abc".

Anonymous contexts in the Erlang SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how to create anonymous contexts in the Erlang SDK:

Context = ldclient_context:set(anonymous, true,
        ldclient_context:new(<<"user-key-123abc">>))
COPY

You must still generate a unique key for anonymous contexts. We recommend using Session IDs or UUIDs.

Private attributes in the Erlang SDK

You can configure the Erlang SDK to treat some or all context attributes as private attributes. You can use private attributes to target contexts without sending data associated with that context back to LaunchDarkly.

When you create the Options map, use the private_attributes key to set private context attributes. When you do this, the SDK does not send the context attributes you specify to LaunchDarkly.

Here's how to set context attributes as private for all contexts:

ldclient:start_instance("sdk-key-123abc", your_instance, #{private_attributes => [email]})
COPY

Here's how to set context attributes as private for a specific context:

ContextWithPrivateAttributes = ldclient_context:set_private_attributes([<<"name">>, <<"/address/street">>],
        ldclient_context:set(<<"name">>, <<"Global Health Services">>,
        ldclient_context:set(<<"email">>, <<"info@globalhealthexample.com">>,
        ldclient_context:set(<<"address">>, #{
            <<"street">> => <<"123 Main Street">>,
            <<"city">> => <<"Springfield">>
        },
    ldclient_context:new(<<"context-key-456def">>, <<"organization">>))))),
COPY

In the example, only the name and /address/street attributes are private for this context.

The Go SDK defines a Context struct and a Builder.

Here's an example:

import (
    "github.com/launchdarkly/go-sdk-common/v3/ldcontext"
    "github.com/launchdarkly/go-sdk-common/v3/ldvalue"
)
// Context with only a key
// by default, the context kind is "user"
context1 := ldcontext.New("context-key-123abc")
// Context with a key plus other attributes
context2 := ldcontext.NewBuilder("context-key-456def").
    Kind("organization").
    Name("Global Health Services").
    SetString("email", "info@globalhealthexample.com").
    SetValue("address", ldvalue.ObjectBuild().
        SetString("street", "123 Main Street").
        SetString("city", "Springfield")).
    Build()
COPY

The most common attribute is the context's key. In this case we used the strings "context-key-123abc" and "context-key-456def". The key is the only mandatory context attribute. The combination of the key and kind should also uniquely identify each context. You can set the kind, or, if you do not set it, LaunchDarkly assumes that the context kind is "user". You can use a primary key, a hash, or some other value, as long as the same context always has the same key. We recommend using a hash if possible.

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

Private attributes in the Go SDK

You can optionally configure the Go SDK to treat some or all context attributes as private attributes. You can use private context attributes for targeting purposes, but the SDK removes private context attributes from the data it sends to LaunchDarkly.

In the Go SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• You can set the configuration option AllAttributesPrivate to true. If you enable this, the SDK removes all attributes for all contexts before it sends the context to LaunchDarkly, except the key and kind.
• You can set the configuration option PrivateAttributes to a list of attribute names. If any context has an attribute named in this list, the SDK removes it before sending the context to LaunchDarkly.

Here's how to to define private attributes:

import (
    ld "github.com/launchdarkly/go-server-sdk/v6"
    "github.com/launchdarkly/go-server-sdk/v6/ldcomponents"
)
var config ld.Config
// Make all attributes private for all contexts
config.Events = ldcomponents.SendEvents().AllAttributesPrivate(true)
// Or, make just the email and address attributes private for all contexts
config.Events = ldcomponents.SendEvents().
    PrivateAttributes("name", "email")
COPY

You can also define a set of private attributes on the context object itself. In the following example, "email" and the "street" field of the "address" attribute are private for this context, in addition to any private attributes that were specified globally:

import (
    "github.com/launchdarkly/go-sdk-common/v3/ldcontext"
)
context := ldcontext.NewBuilder("context-key-123abc").
    Kind("organization").
    Name("Global Health Services").
    SetString("email", "info@globalhealthexample.com").
    SetValue("address", ldvalue.ObjectBuild().
        SetString("street", "123 Main Street").
        SetString("city", "Springfield")).
    Private("email").
    Private("/address/street").
    Build()
COPY

Anonymous contexts in the Go SDK

You can distinguish anonymous contexts in the SDK. Anonymous contexts are only intended for flag evaluations and are not indexed by LaunchDarkly. Anonymous contexts do not appear on the Contexts list. However, they are not excluded from event data, so setting a context as anonymous is not the same as setting its attributes as private. To learn more, read Anonymous contexts.

Here's how:

import (
    "github.com/launchdarkly/go-sdk-common/v3/ldcontext"
)
// Anonymous context with only a key
context1 := ldcontext.NewBuilder("context-key-123abc").Anonymous(true)
// Anonymous context with a key plus other attributes
context2 := ldcontext.NewBuilder("context-key-456def").
    Anonymous(true).
    SetString("country", "Canada").
    Build()
COPY

You still need to generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

Here's an example of a context:

{-# LANGUAGE OverloadedStrings #-}
import LaunchDarkly.Server.Context
import Data.Function ((&))
-- Context with key and kind
context1 :: Context
context1 = makeContext "context-key-123abc" "user"
-- Context with a key plus other attributes
context2 :: Context
context2 = makeContext "context-key-456def" "organization"
    & withAttribute "name" "Global Health Services"
    & withAttribute "email" "info@globalhealthexample.com"
    & withAttribute "address" $ Object $ fromList [("street", "123 Main St"), ("city", "Springfield")]
COPY

The argument to makeUser is the context's key. The key is the only mandatory attribute. The combination of the key and kind should uniquely identify each context. You can use a primary key, an email address, 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".

Private attributes in the Haskell SDK

Optionally, you can configure the Haskell SDK to treat some or all context attributes as private attributes. You can use private context attributes for targeting purposes, but the SDK removes private context attributes from the data it sends to LaunchDarkly.

When you create the Config object, use configSetAllAttributesPrivate to set all context attributes as private. When you do this, all context attributes, except the key and kind, are removed before the SDK sends the context to LaunchDarkly.

Here's how:

makeConfig "sdk-key" & configSetAllAttributesPrivate True
COPY

When you create the Config object, you can list specific private attributes with configSetPrivateAttributeNames. If any context has attributes named in this list, the SDK removes them before sending the context to LaunchDarkly.

Here's an example:

import qualified Data.Set as S
import qualified LaunchDarkly.Server.Reference as R
makeConfig sdkKey
  & configSetAllAttributesPrivate True
  & configSetPrivateAttributeNames (S.fromList $ map R.makeLiteral ["name", "email"])
COPY

You can also define private attribute names on a per-context basis.

For example:

makeContext "key" "user"
  & withName "Sandy"
  & withAttribute "email" "sandy@example.com"
  & withPrivateAttributes (S.fromList $ map R.makeLiteral ["name", "email"])
COPY

Anonymous contexts in the Haskell SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

makeContext "user-key-123abc" "user"
  & withAnonymous True
COPY

You still must generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

In the Java SDK, use a builder pattern to construct contexts.

Here's an example:

LDContext context = LDContext.builder("context-key-123abc")
  .set("firstName", "Sandy")
  .set("lastName", "Smith")
  .set("email", "sandy@example.com")
  .set("groups",
    LDValue.buildArray().add("Google").add("Microsoft").build())
  .build();
COPY

The argument to Builder is the context's key. The key should uniquely identify each context. 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. In this example the hash is "context-key-123abc".

Our Javadoc for ContextBuilder shows you all the attributes that LaunchDarkly supports by default.

Private context attributes in the Java SDK

You can optionally configure the Java SDK to treat some or all attributes as private context attributes. Private context attributes can be used for targeting purposes, but are removed from the context data sent back to LaunchDarkly.

In the Java SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• When creating the LDConfig object, you can call the allAttributesPrivate method, which takes in a boolean parameter. If true, all context attributes except the key for all contexts are removed before the SDK sends the context to LaunchDarkly.
• When creating the LDConfig object, you can call the privateAttributes method, which takes in a set of custom or built-in attributes as a parameter. If any context has a custom or built-in attribute named in this list, the SDK removes it before sending the context to LaunchDarkly.

Here's how to define private attributes:

LDConfig configWithAllAttributesPrivate = new LDConfig.Builder()
  .events(
    Components.sendEvents()
      .allAttributesPrivate(true)
  )
  .build();
LDConfig configWithSpecificAttributesPrivate = new LDConfig.Builder()
  .events(
    Components.sendEvents()
      .privateAttributes("name", "email", "someAttribute")
  )
  .build();
COPY

You can also mark attributes as private when building the context object by calling the privateAttributes builder method. For example:

LDContext context = LDContext.builder("context-key-123abc")
  .set("email", "sandy@example.com")
  .privateAttributes("email")
  .build();
COPY

When the SDK sends this context back to LaunchDarkly, it removes the email attribute.

Anonymous users in the Java SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

LDContext context = LDContext.builder("context-key-123abc")
  .anonymous(true)
  .build();
COPY

You still need to generate a unique key for anonymous users. Session IDs or UUIDs work best for this. Each unique user key registers a user in the system, so capture and reuse your anonymous user's key between requests.

Here's an example of a user:

local user = ld.makeUser({
    key       = "user-key-123abc",
    firstName = "Sandy",
    lastName  = "Smith",
    email     = "sandy@example.com",
    custom    = {
        groups = { "Google", "Microsoft" }
    }
})
COPY

The argument to ld.makeUser is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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 more about configuration options, read the API docs.

In the Node.js SDK, contexts are JSON objects.

Here's an example:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  firstName: 'Sandy',
  lastName: 'Smith',
  email: 'sandy@example.com',
  groups: ['Google', 'Microsoft'],
};
COPY

The key property is the user's key. The key should uniquely identify each user. You can use a primary key, an email address, 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".

Private attributes in the Node.js SDK

You can optionally configure the Node.js SDK to treat some or all attributes as private attributes. You can use private attributes for targeting purposes, but they are removed from the data sent back to LaunchDarkly.

In the Node.js SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• In the LaunchDarkly LDOptions, you can set allAttributesPrivate to true. If you enable this, the SDK removes all user attributes for all users before sending the user to LaunchDarkly, except the key.
• In the LaunchDarkly LDOptions object, you can define a list of privateAttributes. If any user has a custom or built-in attribute named in this list, the SDK removes it before sending the user to LaunchDarkly.

You can also define a set of privateAttributes on the context object. For example:

const context = {
  kind: 'user',
  key: 'user-key-123abc',
  email: 'sandy@example.com',
  _meta: {
    privateAttributes: ['email'],
  }
};
COPY

When the SDK sends this user context back to LaunchDarkly, it removes the email attribute.

Anonymous users in the Node.js SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

const context = {kind:'user', key:'user-key-123abc', anonymous: true};
COPY

You still need to generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

In the PHP SDK, use a builder pattern to construct contexts.

Here's an example:

$context = LDContext::builder("context-key-123abc")
    ->set("firstName", "Sandy")
    ->set("lastName", "Smith")
    ->set("email", "sandy@example.com")
    ->set("groups", ["Google", "Microsoft"])
    ->build();
COPY

The first argument to LDContextBuilder is the context's key. The key should uniquely identify each context. 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. In this example, the hash is "context-key-123abc".

Private attributes in the PHP SDK

You can optionally configure the PHP SDK to treat some or all attributes as private attributes. Private attributes can be used for targeting purposes, but are removed from the data sent back to LaunchDarkly.

In the PHP SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• In the LaunchDarkly config, you can set all_attributes_private to true. If you enable this, the SDK removes all attributes except the key and kind from a context before sending the context to LaunchDarkly.
• In the LaunchDarkly config object, you can define a list of private_attribute_names. If any context has a custom or built-in attribute named in this list, the SDK removes it before sending the context to LaunchDarkly.

You can also mark attributes as private when building the context object by calling the equivalent "private" LDContextBuilder method.

For example:

$context = LDContext::builder('context-key-123abc')
    ->set('email', 'sandy@example.com')
    ->private('email')
    ->build();
COPY

When the SDK sends this context back to LaunchDarkly, it removes the email attribute.

Anonymous contexts in the PHP SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

$context = LDContext::builder("aa0ceb")->anonymous(true)->build();
COPY

You still need to generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

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

In the Python SDK, users are dictionaries.

Here's an example:

context = Context.builder("context-key-123abc") \
    .set("firstName", "Sandy") \
    .set("lastName", "Smith") \
    .set("email", "sandy@example.com") \
    .set("groups", ["Google", "Microsoft"]) \
    .build()
COPY

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

Private context attributes in the Python SDK

You can optionally configure the Python SDK to treat some or all attributes as private context attributes. Private context attributes can be used for targeting purposes, but are removed from the context data sent back to LaunchDarkly.

In the Python SDK there are two ways to define private attributes for the LaunchDarkly client:

• In the LaunchDarkly config, you can set all_attributes_private to true. If you enable this, the SDK removes all context attributes for all contexts before sending the context to LaunchDarkly, except the key.
• In the LaunchDarkly config object, you can define a list of attributes in private_attributes. If any context has a custom or built-in attribute named in this list, the SDK removes it before sending the context to LaunchDarkly.

You can also mark attributes as private when building the context object by calling the private builder method. For example:

context = Context.builder("context-key-123abc") \
    .set("email", "sandy@example.com") \
    .private("email") \
    .build()
COPY

When the SDK sends this context back to LaunchDarkly, it removes the email attribute.

Anonymous users in the Python SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

context = Context.builder("context-key-123abc").anonymous(True).build()
COPY

You still need to generate a unique key for anonymous users. Session IDs or UUIDs work best for this. Anonymous users still count toward your plan's MAU limit, so make sure you capture and reuse your anonymous user's key between requests.

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

Here's an example:

context = LaunchDarkly::LDContext.create({
    key: "user-key-123abc",
    kind: "user",
    firstName: "Sandy",
    lastName: "Smith",
    email: "sandy@example.com",
    groups: ["Google", "Microsoft"]
}
COPY

The key property is the context's key. The key should uniquely identify each context. 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. In this example the hash string is "user-key-123abc".

Private context attributes in the Ruby SDK

You can optionally configure the Ruby SDK to treat some or all context attributes as private context attributes. Private context attributes can be used for targeting purposes, but are removed from the context data sent back to LaunchDarkly.

In the Ruby SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• In the LaunchDarkly config, you can set all_attributes_private to true. If you enable this, the SDK removes all context attributes for all contexts before sending the context to LaunchDarkly, except the key.
• In the LaunchDarkly config object, you can define a list of private_attributes. If any context has a custom or built-in attribute named in this list, the SDK removes it before sending the context to LaunchDarkly.

You can also define a set of privateAttributes on the context object. For example:

context = LaunchDarkly::LDContext.create({
  key: "user-key-123abc",
  kind: "user",
  firstName: "Sandy",
  lastName: "Smith",
  email: "sandy@example.com",
  groups: ["Google", "Microsoft"],
  _meta: {
    privateAttributes: ['email']
  }
})
COPY

When the SDK sends this context back to LaunchDarkly, it removes the email attribute.

Anonymous contexts in the Ruby SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

context = { key: "context-key-123abc", anonymous: true }
COPY

You still need to generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.

The Rust SDK defines a Context struct and a ContextBuilder.

Here's an example:

// Context with only a key
let context = ContextBuilder::new("context-key-123abc").build()?;
// Context with a key plus other attributes
let custom = hashmap! {
    "groups".into() => vec!["Google", "Microsoft"].into(),
};
let context = ContextBuilder::new("context-key-123abc")
    .set_value("first_name", "Sandy".into())
    .set_value("last_name", "Smith".into())
    .set_value("email", "sandy@example.com".into())
    .set_value("Google", "groups".into())
    .set_value("Microsoft", "groups".into())
    .build();
COPY

The most common attribute is the context's key. In the example, the string "context-key-123abc" is the context key. The context key is the only mandatory context attribute. The combination of the key and kind should also uniquely identify each context. You can set the kind, or, if you do not set it, LaunchDarkly assumes that the context kind is "user". 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.

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

Private attributes in the Rust SDK

You can optionally configure the Rust SDK to treat some or all attributes as Private attributes. You can use private attributes for targeting purposes, but the SDK removes them from the user data it sends back to LaunchDarkly.

In the Rust SDK there are two ways to define private attributes for the entire LaunchDarkly client:

• In the LaunchDarkly config object, you can set all_attributes_private to true. If you enable this, the SDK removes all attributes for all contexts before sending the context to LaunchDarkly, except the key and kind.
• In the LaunchDarkly config object, you can define a list of private_attributes. If any contexts has an attribute named in this list, the SDK removes it before sending the context to LaunchDarkly.

You can also define private attributes on the context object. For example:

let context = ContextBuilder::new("context-key-123abc")
    .set_value("email", "youremail@example.com".into())
    .add_private_attribute(Reference::new("email"))
    .build()?;
COPY

When the SDK sends this user back to LaunchDarkly, it removes the email attribute.

Anonymous contexts in the Rust SDK

If your application has both anonymous and logged-in states, you can distinguish logged-in end users from anonymous end users in the SDK.

Here's how:

// Anonymous context with only a key
let context = ContextBuilder::new("context-key-123abc").anonymous(true).build();
// Anonymous context with a key plus other attributes
let context = ContextBuilder::new("context-key-123abc").
    anonymous(true).
    set_value("country", "US".into()).
    build();
COPY

You still need to generate a unique key for anonymous contexts. Session IDs or UUIDs work best for this.