Installations provides a unique identifier for each app instance and a mechanism to authenticate and authorize actions (for example, sending an FCM message).
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2021-08-27 UTC."],[],[],null,["# firebase::installations Namespace\n\nfirebase::installations\n=======================\n\nSummary\n-------\n\n| ### Enumerations ||\n|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------|\n| [Error](#namespacefirebase_1_1installations_1a63045507e4d5479a50cc9455219f584f)`{` ` `[kErrorUnknown](#namespacefirebase_1_1installations_1a63045507e4d5479a50cc9455219f584fa5ba79a07d99409fe9d48cefdd02c531e)`,` ` `[kErrorNoAccess](#namespacefirebase_1_1installations_1a63045507e4d5479a50cc9455219f584fad57b3cb9651c3bc1f7ac67f2d6deb330)`,` ` `[kErrorInvalidConfiguration](#namespacefirebase_1_1installations_1a63045507e4d5479a50cc9455219f584faea0546f226bedc3671829fec15d844ad) `}` | enum [Installations](/docs/reference/cpp/class/firebase/installations/installations#classfirebase_1_1installations_1_1_installations) error codes. |\n\n| ### Classes ||\n|----------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| [firebase::installations::Installations](/docs/reference/cpp/class/firebase/installations/installations) | [Installations](/docs/reference/cpp/class/firebase/installations/installations#classfirebase_1_1installations_1_1_installations) provides a unique identifier for each app instance and a mechanism to authenticate and authorize actions (for example, sending an FCM message). |\n\nEnumerations\n------------\n\n### Error\n\n```c++\n Error\n``` \n[Installations](/docs/reference/cpp/class/firebase/installations/installations#classfirebase_1_1installations_1_1_installations) error codes.\n\n| Properties ||\n|------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `kErrorInvalidConfiguration` | Some of the parameters of the request were invalid. |\n| `kErrorNoAccess` | [Installations](/docs/reference/cpp/class/firebase/installations/installations#classfirebase_1_1installations_1_1_installations) service cannot be accessed. |\n| `kErrorUnknown` | An unknown error occurred. |"]]
