LOGICX package

Apple does not publish this format. The facts on these pages come from the Library of Congress’s description and from open-source readers, written by studying files from recent versions of Logic Pro: LogicFiles, and LogicProFormatWriter for Logic 11.2.2 and 12.0.1.

Package layout

Logic saves a project in one of two forms with the same contents.

Project.logicx/
  Resources/
    ProjectInformation.plist
  Alternatives/
    000/                        the first alternative
      ProjectData
      MetaData.plist
      DisplayState.plist
      DisplayStateArchive
      WindowImage.jpg           optional
      Undo Data.nosync/         may be empty
      Project File Backups/
    001/                        further alternatives, optional
  Media/
    Audio Files/                may be empty

The package form. Finder shows it as one file.

Project/                        a plain folder
  .musicapps-project-folder     an empty marker file
  Audio Files/
  Project.logicx/
    Resources/ProjectInformation.plist
    Alternatives/000/…

The folder form. The inner bundle has no Media folder.

A project needs only ProjectData, MetaData.plist, ProjectInformation.plist and any audio to open; the window image and display state can be missing. The Library of Congress also lists playlists (.plst) and images in Resources.

Alternatives

Each numbered folder in Alternatives is a full saved state of the project. 000 is the default. Their names are in ProjectInformation.plist, and they share the project’s media.

Files in an alternative

File	Kind	Holds
`ProjectData`	Binary	The arrangement, tracks, automation, mixer, plug-ins and MIDI. See ProjectData.
`MetaData.plist`	Binary property list	A summary of the project. ProjectData wins if the two disagree.
`DisplayState.plist`	Binary property list	Windows and editors. Not documented.
`DisplayStateArchive`	Keyed archive	Display settings; a binary property list starting `bplist00`
`WindowImage.jpg`	JPEG	A screenshot of the project window
`Undo Data.nosync/`	Folder	Undo history; the suffix keeps it from syncing to iCloud
`Project File Backups/`	Folder	Earlier copies of the project

ProjectInformation.plist

Key	Type	Meaning	Example
`BundleVersion`	Integer	Format version	`2`
`LastSavedFrom`	String	The app and version that last saved it	`Logic Pro 12.0.1 (6590)`
`HasProjectFolder`	Boolean	True in the folder form	`false`
`projectAssetFlags`	Integer	Asset settings; values not documented	`8265`
`VariantNames`	Dictionary	Alternative number (as text) to name	`{"0": "Project"}`
`VariantNamesV2`	Dictionary	The same, with template tokens	`{"0": "{PROJECT_NAME}"}`
`WasOnceSavedFromLPX`	Boolean	Saved at some time by Logic Pro X	`true`

MetaData.plist

Key	Type	Meaning
`BeatsPerMinute`	Number	Tempo
`SampleRate`	Integer	Sample rate in Hz. Setting it alone does not change a project’s rate.
`SongKey`	String	Musical key
`SongGenderKey`	String	Mode, such as `major`
`SignatureKey`	Integer	Internal key signature index; values not documented
`SongSignatureNumerator`, `SongSignatureDenominator`	Integer	Time signature
`NumberOfTracks`	Integer	Track count
`Version`	Integer	Metadata version, such as 3
`FrameRateIndex`, `SurroundFormatIndex`, `SurroundModeIndex`	Integer	Indexes; values not documented
`HasARAPlugins`	Boolean	Uses ARA plug-ins
`HasGrid`	Boolean	Live Loops grid in use
`isTimeCodeBased`	Boolean	Uses timecode
`AudioFiles`, `UnusedAudioFiles`	Array	Paths of the audio files used and unused
`SamplerInstrumentsFiles`, `QuicksamplerFiles`, `ImpulsResponsesFiles`, `UltrabeatFiles`, `PlaybackFiles`	Array	Paths of other assets. The spelling `ImpulsResponsesFiles` is Logic’s.

Session Player data

Drummer and Session Player settings are UTF-8 JSON embedded in ProjectData, found by LogicFiles by scanning for it. The state includes drummerModelTrackStates, keyed by track UUID, with fields such as selectedCharacterIdentifier and isUsingProducerKit. Region presets include RegionType and Preset with its Parameters: intensity and dynamics (0 to 127), humanize, swing, rComp, mComp and fillsAmount (0 to 100), and variation (1 to 4).

Not confirmed

The contents of DisplayState.plist, and the values of index and flags fields.
Whether the keys differ in Logic before version 11.

.LOGICX File Format – Package