Add-on File Types and Extensions Reference

When distributing add-ons or worlds, you compress the development folders into standard ZIP archives and rename their extensions. Minecraft Bedrock registers these extensions with the operating system so that double-clicking a file launches the game and imports the content automatically into the internal storage folders.

When creating these archives, zip the contents of your pack folder directly so that manifest.json sits at the root of the archive, rather than zipping the parent folder itself. If manifest.json is buried inside a subfolder within the archive, the game importer will fail to recognize the pack.

Almost all declarative definitions in both Behavior Packs (BP) and Resource Packs (RP) use the .json extension. This includes entities, blocks, items, recipes, loot tables, spawn rules, client entity definitions, models, particles, and UI screens. The engine parses these files during pack loading and validates them against internal schemas tied to the format_version string.

While standard JSON strictly forbids comments, the Bedrock engine's parser supports JSON with Comments (JSONC) in most definition files, allowing single-line (//) and multi-line (/* */) comments. However, trailing commas after the last element in an object or array will cause a syntax error in newer format versions. Certain files in the RP/models/entity/ directory frequently use the double extension .geo.json by convention, though the engine only requires that they end in .json.

{
  "format_version": "1.20.50",
  "minecraft:item": {
    "description": {
      "identifier": "example:copper_wrench",
      "menu_category": {
        "category": "equipment"
      }
    },
    "components": {
      "minecraft:max_stack_size": 1,
      "minecraft:hand_equipped": true,
      "minecraft:icon": {
        "texture": "copper_wrench"
      }
    }
  }
}

Behavior packs support two distinct types of executable text files: command functions (.mcfunction) and Script API code (.js). Files ending in .mcfunction live in the BP/functions/ directory and contain plain-text lists of slash commands, executed sequentially from top to bottom within a single game tick. Commands inside a function file are written without the leading forward slash, and lines starting with a hash symbol (#) are ignored as comments.

JavaScript files (.js) belong in the BP/scripts/ directory and run inside the QuickJS engine when the manifest declares a script module. If you author your scripts in TypeScript (.ts), you must compile them down to standard ES2020 JavaScript (.js) before the game can load them; Bedrock cannot execute TypeScript files directly.

import { world } from "@minecraft/server";

world.afterEvents.playerSpawn.subscribe((event) => {
  if (event.initialSpawn) {
    event.player.sendMessage("Welcome to the server!");
  }
});

All 2D artwork, block textures, item icons, entity skins, and custom UI elements reside in the RP/textures/ directory. Standard raster images use the .png format, while high-end Physically Based Rendering (PBR) and deferred rendering packs can also utilize .tga (Targa) files when distinct alpha channel handling is required without PNG compression artifacts.

When references to textures are made inside JSON files such as terrain_texture.json or item_texture.json, you always omit the file extension (.png or .tga). This allows the engine to dynamically select between standard textures or Texture Set (.texture_set.json) definitions if Vivid Visuals or ray tracing is active.

Sound effects and music tracks belong in the RP/sounds/ folder and are mapped to sound events via RP/sounds/sound_definitions.json. Just like texture references, paths inside sound_definitions.json omit the file extension. Ogg Vorbis (.ogg) is the standard, recommended format for all custom audio because it balances small file sizes with reliable cross-platform decoding.

The engine uses the FMOD audio system under the hood. While .wav files and FMOD Sound Banks (.fsb) are technically supported by the audio engine, .wav files drastically inflate pack size and must be formatted strictly as 16-bit PCM to play cleanly. Mono audio files are required for any 3D positional sound (like entity noises or block breaks); stereo files will bypass positional attenuation and play at constant volume regardless of the player's distance.

All human-readable text in an add-on—such as item names, entity names, custom death messages, and UI labels—is stored in .lang files inside the RP/texts/ directory (and inside BP/texts/ exclusively for translating pack manifest names and descriptions). Each file is named after a specific locale code, such as en_US.lang or ja_JP.lang, and listed inside RP/texts/languages.json.

A .lang file uses a simple key=value format per line. Comments begin with two hashes (##) and can be placed on their own line or after a tab character on a translation line. These files must be encoded in UTF-8 without a Byte Order Mark (BOM).

## Items
item.example:copper_wrench.name=Copper Wrench

## Entities
entity.example:Automaton.name=Copper Automaton	## Spawn egg and nametag text

Applies to all modern Minecraft Bedrock versions (1.16.0 through 1.21+). No experimental toggles are required for standard file parsing, though specific Script API modules in .js files may require Beta APIs depending on the module version.

Read out of the game itself, so the ids match the version you are building for.