manifest property:version), the package metadata (user_meta), and a package commit message (message).version is used to ensure backwards compatibility should the serialization format change. There is currently only one valid version: v0.user_meta is used to store any user-defined package metadata. In this case this package has no package metadata (yet) so user_meta is omitted.message stores the package commit message. It will be None if the package is pushed without a commit message. The field is omitted if the package was never subject to a push.logical_key - The path to the entry within the package.physical_keys - A list of files. Currently this field will always have a single entry. This field is omitted if the entry is a directory.size - The size of the entry in raw bytes. This field is omitted if the entry is a directory.hash - Materialized packages record a content hash for every entry in the package. This field is used to ensure package immutability (the tophash is partly a hash of these hashes).dict fragment of the form {'type': 'SHA256', 'value': '...'}. Un-materialized package entries have a hash of None, as in our example. Directory entries omit this field.meta - Package entry metadata. Package entries lacking metadata will have a meta of {} (empty dict).build, and push to handle sending manifests to and fro. However, there may be advanced use cases where you want to save or load a manifest directly. For that, you can use the low-level manifest API: