> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bluejutzu.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# batch

> Apply the same tag fields to every audio file in a directory.

```bash theme={"system"}
bmux batch <directory> [options]
```

`batch` is [`tag`](/bmux/commands/tag) for a whole album folder at once — set the artist, album,
year, and cover art on every file in one pass. Title and track number are inherently per-file, so
edit those individually with `tag`.

```bash theme={"system"}
bmux batch "Spaces" --artist "Nils Frahm" --album "Spaces" --year 2013 --cover front.jpg
```

## Arguments

<ParamField path="directory" type="string" required>
  Directory of audio files (`.mp3`, `.flac`, `.m4a`/`.m4b`).
</ParamField>

## Options

<ParamField query="--artist" type="string">Set the artist on every file.</ParamField>
<ParamField query="--album" type="string">Set the album on every file.</ParamField>
<ParamField query="--year" type="number">Set the release year on every file.</ParamField>

<ParamField query="--cover" type="string">
  Embed this cover art on every file, resized to fit 300x300px.
</ParamField>

<ParamField query="--no-recursive" type="boolean">
  Only tag files directly inside the directory. By default subdirectories are searched too.
</ParamField>

<ParamField query="--unique-artist-tag" type="boolean" default="false">
  Append an invisible per-album suffix to each file's artist tag — see
  [`tag`](/bmux/commands/tag#the-unique-artist-tag-workaround). Off by default.
</ParamField>

<ParamField query="--musicbrainz" type="boolean" default="false">
  Look up title/artist/album/year on [MusicBrainz](https://musicbrainz.org) for whatever's still
  blank after the flags above, and its cover art via the Cover Art Archive if no cover is set.
  Fields you passed explicitly, or that the file already had, are never overwritten.

  <Warning>
    This is the **only** thing in bmux that contacts a third party — everything else runs fully
    offline. It's off by default, and printing a one-line warning when you turn it on.
  </Warning>
</ParamField>

<ParamField query="--dry-run" type="boolean" default="false">
  Show what would change without writing any files.
</ParamField>

## A failed file doesn't stop the batch

Like `convert` and `optimize`, one bad file is reported and skipped — the rest of the directory
still gets tagged, and the command exits non-zero only if something failed:

```
✔ Spaces/01 - Says.mp3
✔ Spaces/02 - Says (reprise).mp3
✘ Spaces/03 - corrupt.mp3: not a valid FLAC file (missing "fLaC" marker)

2 succeeded, 1 failed.
```