WTEM (World Translation Extractor Mod)

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WTEM is a client-side Fabric mod that turns hardcoded text in Minecraft worlds, world data packs and world-generated structures into translation keys, and writes the matching i18n entries. It supports several Minecraft versions.

Parts of this mod were created with AI assistance. The AI tools used include gpt-5.6-sol and claude-opus-5.

Supported versions

Release	Game versions	Java
1.21.1	1.21 ~ 1.21.1	21
1.21.3	1.21.2 ~ 1.21.3	21
1.21.4	1.21.4	21
1.21.5	1.21.5	21
1.21.8	1.21.6 ~ 1.21.8	21
1.21.10	1.21.9 ~ 1.21.10	21
1.21.11	1.21.11	21
26.1.x	26.1 ~ 26.1.2	25
26.2.x	26.2	25

Usage

1. Put the mod file for your Minecraft version into the client's mods directory.
2. Start the game, select the target world in the singleplayer world list and open its "Edit" page.
3. Click the "Extract" button.
4. Create a backup on the backup confirmation page. Always backing up is strongly recommended; extraction modifies world data in place.
5. Wait for extraction to finish. The screen shows chunk progress and a warning count; the game log has the details.

Extraction can be cancelled once it has started. Chunks, SavedData and structures already written before the cancellation or before an error are not rolled back, so back up first.

What gets extracted

Save data:

• Block entity text in chunks, such as container names, signs and command block output.
• Text in entities and their nested data: passengers, equipment, inventories, villager trades.
• Scoreboard team, objective and score display names.
• Custom boss bar names.
• NBT structures actually present in the world's generated/<namespace>/structure(s).
• Every non-vanilla compressed *.dat SavedData file below the world's data/ directory, including nested custom files, with conservative field detection and per-file/path filtering. Every NBT string in the selected scope records a saved_data_string warning; only strings identified as text components are extracted. The recognized field names are configurable through saved_data_text_fields (which includes back_text by default).

Datapacks:

• Known text fields in advancements, enchantments, jukebox songs, armor trims, paintings, instruments, dialogs and dimension types (for example attributes.minecraft:gameplay/bed_rule.error_message).
• Translatable text components in item modifiers, loot tables and predicates.
• Entity, block entity and item text in NBT structures.
• Text component arguments in functions, entity text in the nbt argument of summon, and arguments that parse as an item or a block entity, such as give's item components and the block entity NBT of setblock and fill.

Output

A finished extraction may produce:

• <world>/en_us.json: the mapping from translation keys to the original text.
• <world>/en_us.csv: the extraction report, recording where each piece of text was found. See the next section.
• <world>/datapacks/<original pack>_<short hash>_wtem/: an override data pack paired with the original world data pack.
• The default client resource pack, resources.zip, under <world>/ before 26.1 and under <world>/resourcepacks/ in 26.1 and newer.
• Modified block entities, entities, scoreboard, bossbar and structures, with hardcoded text components replaced by translate components.

WTEM will not modify the original world datapack. The generated new data package will only save the resources that have actually changed and pack.mcmeta. Before re-entering the world, confirm in the datapack configuration that the overlay pack is enabled and above the original pack.

Extraction report

Extraction also exports a report, named after the language file with a .csv suffix.

Its columns:

Column	Contents
key	The generated translation key.
text	The original text that was replaced.
source	The extraction stage, i.e. the name used in the config's stages, for example region or datapacks.
location	Where the data lives: dimension and chunk, data pack and resource ID, or structure file.
subject	The chain of containing objects, outermost first, joined by >, for example minecraft:chest (12, 64, -30) > minecraft:shulker_box.
reused	Whether this occurrence reused an existing key. true means it added no language file entry, and that editing the key affects more than one place.
replaced	Whether the original world/data-pack value was replaced with a translate component. false identifies catalog-only text instead of a replaced one.

A key that appears in several places has one language file entry but one report row per occurrence, so the report usually has more rows than the language file has entries. If extraction is cancelled or fails partway, the part already written is exported along with the language file.

Warning types

Warnings are non-fatal diagnostics. Each warning includes its type and the source file, resource ID, command, or NBT path that caused it. The warnings below identify cases that need review or could not be rewritten safely.

Type	Meaning
region_snbt	A per-region SNBT export could not be written.
saved_data	A SavedData file could not be read, decompressed, parsed, or selected.
saved_data_string	A plain string was found in the selected SavedData scope. It remains unchanged unless it is in a configured text field.
datapack	A data-pack resource could not be read or processed.
datapack_staging	A generated override data pack could not be staged or published.
function_index	The function call index could not be built for a data pack.
function_parse	A function command could not be parsed by Minecraft's command parser.
function_command	A parsed command could not be processed.
function_reparse	A rewritten command did not pass the validation reparse.
function_component_rewrite	A text component or structured argument in a function could not be rewritten safely.
function_selector_name	A selector name that looks like a text-bearing argument could not be resolved.
function_storage_string	A literal string was written directly into command storage by data modify storage ... set value.
function_macro_binding	A macro caller/storage binding was missing, ambiguous, or not statically resolvable.
function_macro_restore	A materialized macro command could not be restored and validated for its callers.
writable_book	A writable-book writable_book_content.pages[*].raw string was cataloged but cannot be replaced by a component (replaced=false).
written_book_string	A written-book plain string such as author remains unchanged.
generated_structure	A world-generated structure could not be read or rewritten.
language	The primary language catalog could not be written.
manifest	The CSV extraction report could not be written.
schema	The optional extraction schema could not be written.
resource_pack	The optional client resource pack could not be written.
ai_key_naming	AI semantic key naming failed or returned an invalid key; structured naming is used as a fallback.
ai_translation	The AI translation request or response failed; the normal catalog is retained.
close	An extraction resource could not be closed cleanly after the run.

Configuration

The first launch writes a default config to config/wtem.json, with every option spelled out at its default value so it can be edited directly. Every option is optional: deleting one or leaving it out keeps the default behavior. You can also access the YACL configuration interface by clicking the Configuration button in the extraction screen.

The Select sources button on the extraction screen opens a YACL screen for datapacks, SavedData files, and entity/block entity types. The Configuration button is reserved for the other extraction settings. Editing wtem.json externally is hot-reloaded automatically. A running extraction keeps its startup snapshot, so changes apply to the next run.

{
  "stages": {
    "region": true,
    "entities": true,
    "scoreboard": true,
    "boss_bar": true,
    "datapacks": true,
    "generated_structures": true,
    "storage": true
  },
  "resources": {
    "advancement": true,
    "enchantment": true,
    "jukebox_song": true,
    "trim_material": true,
    "trim_pattern": true,
    "painting_variant": true,
    "instrument": true,
    "dialog": true,
    "dimension_type": true,
    "item_modifier": true,
    "loot_table": true,
    "predicate": true,
    "function": true,
    "structure": true
  },
  "key_reuse": {
    "default": true,
    "overrides": {}
  },
  "key_naming": {
    "scheme": "structured",
    "random_length": 8
  },
  "nbt_max_depth": 32,
  "rebuild_nested_keys": false,
  "skipped": {
    "command_block_output": true,
    "filtered_text": true
  },
  "skipped_paths": [
    "animated_java:function"
  ],
  "builtin_entries": {
    "wtem.blank": "",
    "wtem.space": " ",
    "wtem.0": "0",
    "wtem.1": "1",
    "wtem.2": "2",
    "wtem.3": "3",
    "wtem.4": "4",
    "wtem.5": "5",
    "wtem.6": "6",
    "wtem.7": "7",
    "wtem.8": "8",
    "wtem.9": "9"
  },
  "language_file": "en_us.json",
  "saved_data_text_fields": [
    "name",
    "custom_name",
    "customname",
    "title",
    "subtitle",
    "description",
    "text",
    "message",
    "label",
    "display_name",
    "displayname",
    "lore",
    "messages",
    "pages",
    "lines",
    "raw",
    "front_text",
    "back_text",
    "prompt",
    "tooltip",
    "error_message"
  ],
  "filters": {
    "region": [],
    "datapack": [],
    "storage": [],
    "entity": [],
    "block_entity": [],
    "selection": {
      "datapacks": [],
      "entities": [],
      "block_entities": [],
      "storage_files": []
    }
  },
  "outputs": {
    "export_region_snbt": false,
    "export_schema": false,
    "region_snbt_directory": "wtem/regions",
    "schema_file": "wtem-schema.json"
  },
  "ai_translation": {
    "enabled": false,
    "endpoint": "https://api.deepseek.com",
    "api_key": "",
    "model": "deepseek-v4-flash",
    "target_language": "zh-CN",
    "output_file": "zh_cn.json",
    "timeout_seconds": 60,
    "protocol": "responses",
    "translation_prompt": "Translate the values of the supplied JSON object into {target_language}. Return only one JSON object with exactly the same keys. Preserve Minecraft formatting codes, placeholders such as %s and %1$s, escape sequences, whitespace, and intentional line breaks. Do not translate JSON keys, commands, identifiers, or formatting tokens.",
    "key_naming_prompt": "Create one concise semantic Minecraft translation key for the supplied text and suggested_path. Return only a JSON object in the form {\"key\":\"...\"}. Use lowercase ASCII letters, digits, underscores, and dots only. Prefer the source category (item, entity, block, sign, book, or datapack) as the first segment and preserve the semantic role such as .name, .title, or .description as the last segment. Translate the meaning into concise English key words even when the visible text is in another language. Describe the visible text rather than the material id: for example, The Best Sword on a wooden sword should be item.the_best_sword.name. Never include numeric occurrence indexes."
  },
  "resource_pack": {
    "enabled": true,
    "format": "zip",
    "name": "resources.zip",
    "description": "WTEM translations",
    "pack_format": 0
  }
}

• stages: switches per extraction stage. region is block entities in chunks, entities is entity chunks, storage recursively reads every *.dat below data/, and the rest are the scoreboard, boss bars, world data packs and world-generated structures.
• resources: switches per data pack resource type, keyed by registry directory name. The generated file lists every type the current version actually supports; a type that is not listed counts as enabled.
• key_reuse: whether identical text reuses an existing translation key. default is the global policy and overrides overrides it by key prefix, with the longest matching prefix winning. To translate the same text separately in different places, set the matching prefix to false, for example {"datapack.": false}.
• key_naming: how translation keys are named. See below.
• nbt_max_depth: the recursion limit for NBT extraction, which keeps mutually nested items and the like from exhausting the stack. Each nested item, entity or block entity costs one level, and data past the limit is left as it is. A value below 1 is treated as the default.
• rebuild_nested_keys: whether block_entity_data on an item names itself from scratch. It is false by default, so, reuse aside, a wooden sword inside a shulker box gets a key such as item.shulker_box.1.container.wooden_sword.1.name. With true, nested items restart their key and produce a key such as item.wooden_sword.1.name.
• skipped: text that can be translated but usually does not need to be. See below.
• skipped_paths: skips resources below selected directories under data/; skipped resources are not written to the companion pack. The resource-location form is like <namespace>:<resource path>: animated_java:function matches data/animated_java/function/**. *:function/generated matches that directory in every namespace, and a resource path of * skips a whole namespace.
• builtin_entries: entries seeded into the language file. Extracted text that matches one of them reuses its key instead of taking a key of its own. The defaults seed the empty string, a space and 0~9: text with no translation value that nonetheless shows up constantly (blank sign lines, numbers on a scoreboard), which after seeding takes one line each. An empty object {} seeds nothing; deleting the whole option keeps the defaults.
• language_file: the name of the language file written into the world directory. Only a plain file name is accepted; a name containing a path separator or not ending in .json is ignored.
• saved_data_text_fields: field names used to identify likely text components while scanning SavedData. The default list includes back_text; every other string in the selected SavedData scope is retained and reported as saved_data_string instead of being guessed as text.
• filters: unified source filters. A normal rule includes a location, ! excludes it, and */? are wildcards; exclusions always win. Region locations are dimension/chunk/x_z, data-pack locations are pack/namespace:path, SavedData locations are <path below data>.dat/<NBT path>, and the entity filters match full namespaced type IDs.
• filters.selection: exact choices saved by the extraction screen. Data packs and SavedData files are discovered from the current world. Entity and block-entity choices come from the current version's registries. An empty list means all current. Unchecking every item stores the internal sentinel ["!none"], which explicitly means none.
• outputs: enables per-chunk SNBT files under the world-relative region_snbt_directory and a schema JSON file.
• ai_translation: when enabled, sends the complete catalog in one request to an OpenAI-compatible Responses or chat-completions endpoint. You may enter either a BaseURL or a complete /responses or /chat/completions URL; protocol selects the protocol when a BaseURL is used. translation_prompt supports the {target_language} placeholder, and key_naming_prompt controls optional AI semantic key naming.
• resource_pack: when enabled, writes a folder, ZIP, or both using only the configured pack name. The pack contains pack.mcmeta and assets/wtem/lang/ catalogs.

Skipped text

Both options default to true. Set to true, the matching text stays out of the language file and the original text in the save is left alone.

• command_block_output: the cached result of the last execution of a command block or command block minecart (LastOutput).
• filtered_text: the chat-filtered copy of sign lines and written book pages (filtered_messages / filtered).

Key naming schemes

• scheme:
  • structured (default): readable keys derived from the extraction site, for example entity.zombie.1.name. Because extraction is unordered, repeated extraction is not guaranteed to be consistent.
  • hashed: keys derived from a hash of the extraction site, of the form wtem.<hash>. Repeated extraction of the same save produces the same keys.
  • random: random letters, of the form wtem.<random>. The key is unrelated to the extraction site, and repeated extraction is not guaranteed to be consistent.
  • ai: sends the original text and suggested source path to the configured OpenAI-compatible endpoint. For example, a wooden sword named The Best Sword may become item.the_best_sword.name. Responses must be valid dotted keys.
• random_length: how many random letters the random scheme uses. 8 by default.

Development and building

The repository's default active project is 26.2.x. Before and after editing shared sources, use Stonecutter's switch tasks to generate the sources for the version you want.

PowerShell example:

.\gradlew.bat "Set active project to 1.21.11"
.\gradlew.bat :1.21.11:compileJava :1.21.11:compileTestJava :1.21.11:test :1.21.11:validateAccessWidener

Build and collect the release JAR for one version (26.2.x):

.\gradlew.bat "Set active project to 26.2.x"
.\gradlew.bat :26.2.x:buildAndCollect

The output lands in build/libs/<mod version>/. Before committing, run:

.\gradlew.bat "Reset active project"

which restores the shared sources to the 26.2.x state the repository is configured for.

To build every version in one go:

.\gradlew.bat buildAll

License and credits

This project uses CC BY 4.0. You may copy, modify and redistribute it, including commercially, as long as you keep the attribution.

Attribution means naming the author, pointing at this project, stating the license (CC BY 4.0, with its text or a link), and saying whether you changed anything. When redistributing the mod or a modified version, shipping LICENSE and NOTICE.

Distributing the tool's output requires attribution too. When you publish the language file, the extraction report or the generated data packs, on their own or inside a world, state that those files were produced by WTEM and give the attribution above. This covers the generated files only, not the world extracted from, translations, or anything else you distribute alongside them.

Inspired by WorldTranslationExtractor.