# appconfigdata ## Description AppConfig Data provides the data plane APIs your application uses to retrieve configuration data. Here’s how it works: Your application retrieves configuration data by first establishing a configuration session using the AppConfig Data StartConfigurationSession API action. Your session’s client then makes periodic calls to GetLatestConfiguration to check for and retrieve the latest data available. When calling `StartConfigurationSession` , your code sends the following information: * Identifiers (ID or name) of an AppConfig application, environment, and configuration profile that the session tracks. * (Optional) The minimum amount of time the session’s client must wait between calls to `GetLatestConfiguration` . In response, AppConfig provides an `InitialConfigurationToken` to be given to the session’s client and used the first time it calls `GetLatestConfiguration` for that session. #### WARNING This token should only be used once in your first call to `GetLatestConfiguration` . You *must* use the new token in the `GetLatestConfiguration` response (`NextPollConfigurationToken` ) in each subsequent call to `GetLatestConfiguration` . When calling `GetLatestConfiguration` , your client code sends the most recent `ConfigurationToken` value it has and receives in response: * `NextPollConfigurationToken` : the `ConfigurationToken` value to use on the next call to `GetLatestConfiguration` . * `NextPollIntervalInSeconds` : the duration the client should wait before making its next call to `GetLatestConfiguration` . This duration may vary over the course of the session, so it should be used instead of the value sent on the `StartConfigurationSession` call. * The configuration: the latest data intended for the session. This may be empty if the client already has the latest version of the configuration. #### WARNING The `InitialConfigurationToken` and `NextPollConfigurationToken` should only be used once. To support long poll use cases, the tokens are valid for up to 24 hours. If a `GetLatestConfiguration` call uses an expired token, the system returns `BadRequestException` . For more information and to view example CLI commands that show how to retrieve a configuration using the AppConfig Data `StartConfigurationSession` and `GetLatestConfiguration` API actions, see [Retrieving the configuration](http://docs.aws.amazon.com/appconfig/latest/userguide/appconfig-retrieving-the-configuration) in the *AppConfig User Guide* . ## Available Commands * [get-latest-configuration](get-latest-configuration.md) * [start-configuration-session](start-configuration-session.md)