File Renaming

AB has four rename methods: pn, advance, template and none. Select one in Settings → Manage Setting → Rename Method. The default is pn.

Since 4.0, plugins supply the rename methods:

• AB supplies none. It is always available.
• The built-in rename plugin supplies pn, advance and template. This plugin is enabled by default.
• Other plugins can add rename methods. When you enable such a plugin, its methods appear in the drop-down.

If you disable the rename plugin in Settings → Plugins, AB handles every series as none. The same occurs when AB disables the plugin after 5 errors in a row. When the selected method is not available, AB writes one log entry and uses none.

pn

Short for pure name. This method uses the title that AB parses from the file name.

Example:

[Lilith-Raws] 86 - Eighty Six - 01 [Baha][WEB-DL][1080p][AVC AAC][CHT][MKV].mkv
>>
86 - Eighty Six S01E01.mkv

advance

Advanced renaming. This method uses the name of the series folder.

/downloads/Bangumi/86 - Eighty Six(2023)/Season 1/[Lilith-Raws] 86 - Eighty Six - 01 [Baha][WEB-DL][1080p][AVC AAC][CHT][MKV].mkv
>>
86 - Eighty Six(2023) S01E01.mkv

pn and advance give the same result as in 3.x. Movies do not get SxxExx. Subtitle files get the language before the extension, for example .zh.ass.

template

This method uses your own template. Write the template in the template option of the rename plugin in Settings → Plugins.

none

No renaming. Files keep their names.

Template Rename

The default template is below. For normal episodes it gives the same result as pn. For movies, pn adds no SxxExx, but the default template does:

{{ title }} S{{ season|pad(2) }}E{{ episode|pad(2) }}

The template uses Jinja2 syntax. AB renders it in a sandbox. Variables:

Variable	Meaning	Example
title	Title that AB parses from the file name	Frieren
bangumi_name	Name of the series folder	Frieren (2023)
season	Season, from the Season folder. It includes the season offset	1
episode	Episode. It includes the episode offset. Half episodes keep the decimal	5, 12.5
episode_type	episode, movie or special	episode
group	Release group. It can be empty	ANi
kind	media (video) or subtitle	media
language	Subtitle language. It is empty for videos	zh

The filter pad(n) adds zeros to the integer part of a number until it has n digits. If you do not give n, n is 2. The decimal part does not change. {{ episode|pad(3) }} gives 005. {{ 12.5|pad(2) }} gives 12.5.

• The template makes only the base of the file name. AB adds the extension. For subtitles, AB adds .<language> before the extension, for example .zh.ass.
• The template does not handle movies in a special way. To name movies differently, use episode_type, for example {% if episode_type == "movie" %}{{ bangumi_name }}{% else %}…{% endif %}. The check at save time renders only one sample episode. An error in a branch that the sample does not use shows only when AB renames a file.

Example: [{{ group }}] {{ bangumi_name }} - {{ episode|pad(2) }} → [ANi] Frieren (2023) - 05.mkv

Template errors

• When you save: AB renders the template once with a sample file. If the syntax is incorrect, a variable does not exist, or the result is not a valid file name, AB does not save the template. The old template stays.
• When AB renames: if a file does not render, the result is empty, or the result contains /, \ or a control character, the file keeps its name. AB sends a "Files kept their names" notification. AB sends it one time for each torrent and reason while AB runs. AB does not add the ab:renamed tag to the torrent. After you correct the template, AB tries again in the next round. AB does not use pn as a fallback.
• When you edit config.json manually: if the saved template is not valid, the full rename plugin does not load. Then pn, advance and template are not available, and AB handles every series as none. The plugin card shows the error.

WARNING

A change of rename method (or of the template) applies only to torrents that AB organizes after the change. AB does not rename torrents that it organized before (torrents with the ab:renamed tag).

For the config.json keys, see Bangumi Manager.

Collection Renaming

AB supports renaming collections. Collection renaming requires:

• Episodes are in the collection's first-level directory
• Episode numbers can be parsed from file names

AB can also rename subtitle files in the first-level directory.

After renaming, episodes and directories are placed in the Season folder.

Renamed collections are moved and categorized under BangumiCollection.

Episode Offset

Since v3.2, AB supports episode offset for renaming. This is useful when:

• RSS shows different episode numbers than expected (e.g., S2E01 should be S1E29)
• Anime has "virtual seasons" due to broadcast gaps

When an offset is configured for a bangumi, AB automatically applies it during renaming:

Original: S02E01.mkv
With offset (season: -1, episode: +28): S01E29.mkv

To configure offset:

1. Click on the anime poster
2. Open Advanced Settings
3. Set Season Offset and/or Episode Offset values
4. Or use "Auto Detect" to let AB suggest the correct offset

See Bangumi Management for more details on auto-detection.

After Renaming

After AB renames a torrent, it publishes a "torrent organized" event. AB also publishes this event when the rename method is none. Built-in plugins can then do more work on the files:

• Hard Links to a Media Library: links the organized files into a different folder. The torrent continues to seed from the download folder.
• media-server-refresh: asks Jellyfin, Emby or Plex to refresh the library. See Bangumi Manager.