# addMetadata(_:completion:) Adds metadata to the sample. ``` func addMetadata(_ metadata: [String : Any], completion: @escaping @Sendable (Bool, (any Error)?) -> Void) ``` ## Parameters `metadata` The metadata dictionary contains extra information describing all the samples created by the builder. The dictionary’s keys are all strings. The values may be strings, numbers, or date objects. For a complete list of predefined metadata keys, see . Using predefined keys helps facilitate sharing data between apps; however, you are also encouraged to create your own, custom keys as needed to extend the samples’ capabilities. `completion` The completion handler called by the builder after it attempts to add the metadata to the series. The completion handler takes the following parameters: - `success`: A Boolean value that indicates whether the builder successfully added the heartbeat. - `error`: If the `success` parameter is , this contains an object that describes the error; otherwise, `nil`. ## Discussion The builder adds the metadata to the resulting series sample. It incorporates new data using . --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)