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Export and import

Metronomo does not sync to the cloud, but it does provide Export and Import capability via a simple text file JSON schema. This allows you to back up and restore your Grooves and transport them between devices and app installs. The JSON file also makes Grooves programmatically accessible, for whatever possibilities that opens up.

Exporting

Utilities → Export writes your saved Groove library to a file. The file is named metronomo-yyyy-mm-dd-hhmmss.json, stamped in UTC to the second so a folder of export files sorts chronologically. If the default name is taken, the new file appends a count, e.g. metronomo-yyyy-mm-dd-hhmmss (2).json.

The export file

The export file is a plain UTF-8 JSON document. You can open it in any text editor.

The library schema

{
  "format": "metronomo.backup",
  "version": 1,
  "exportedAt": "2026-08-26T14:22:31.004Z",
  "appVersion": "1.0.0 (4)",
  "grooves": []
}

The Groove schema

Each entry in the grooves array defines a Groove:

{
  "id": "mt1d6i07-4f2a91",
  "name": "Shuffle",
  "bpm": 96,
  "beats": 4,
  "accents": [
    "strong",
    "medium",
    "soft",
    "medium"
  ],
  "subdivision": 3,
  "subdivisionPatterns": {
    "3": [
      "mute",
      "tick",
      "soft"
    ],
    "4": [
      "mute",
      "tick",
      "strong",
      "tick"
    ]
  },
  "countIn": 4,
  "alarm": {
    "enabled": true,
    "seconds": 300
  },
  "pause": {
    "enabled": false
  },
  "createdAt": 1787220902311,
  "updatedAt": 1787752724902
}

An accent level on a beat or a subdivision slot is one of strong, medium, soft, tick, or mute. In a subdivisionPatterns entry, slot 0 is the beat’s own place in the grid and is always mute.

Importing

Utilities → Import imports any UTF-8 file that observes the Grooves JSON schema.

A file that parses opens a dialog box with two modes:

• Merge adds the file’s Grooves to your library. Nothing you have already saved is changed or dropped.
• Replace discards your library and installs the import in its place. This cannot be undone.

Under either mode, the Groove you are working on is left alone and can still be saved after the import even if its saved version is replaced. Settings and Preferences are unaffected.

Names and id collisions

Collisions under Merge, or between Grooves in the same file:

• An id already taken forces the duplicate to a fresh id and the name <name> (imported).
• A name already taken forces the duplicate to a new name with a number: Shuffle arriving against Shuffle becomes Shuffle (2), then Shuffle (3).

Parse failures

Four conditions stop an import before anything is read. In each case nothing on the device changes:

The last one is a guard on Replace more than Merge; it prevents you from replacing your Groove library with an empty set.

Import repairs

Given that a Metronomo Grooves file can be created and edited outside of Metronomo, the Import process is designed to repair boundary issues, unrecognized values, and unrecognized keys:

• A number outside the range for a known property is clamped.
• A number that is missing or unreadable for a numeric property takes the app’s default.
• An unrecognized accent level label becomes medium.
• An accents array that does not match the beat count is trimmed or padded.
• Keys the app does not know are dropped.

In short, a Groove that survives import is one the app could have created itself.

Four things are not repaired by Import:

• A Groove with no usable name, or no usable beats, is skipped entirely.
• A subdivisionPatterns entry is kept only if it describes its own count exactly. If any level is unrecognized, that entry is dropped and replaced by the default tick level.
  • Unlike accents, a subdivisionPatterns entry is never trimmed or padded to fit.
  • Slot 0 is always pinned back to mute, since the beat sounds from accents.
• A file whose format is not metronomo.backup is not importable.
• An alarm or pause whose seconds is missing or unreadable is switched off, rather than set to a default.