Dumpy is a developer only mod for dumping resolved, in-game data at runtime.

What it does:

Dumpy answers: “What does the game think is true right now?” after datapacks, configs, and reloads have applied. It’s built for debugging, balancing, validation, and pack development.

Features:

Rich runtime dump commands (registries, recipes, tags, loot, worldgen, config/state, players)
Output formats: JSON, Markdown, CSV
Filtering for most dumps (--namespace, --contains, --type, etc.)
Optional diff tracking to compare dumps over time
Exports .json to worldsave folder, specifically: <world>/avalorn_dumps/<category>_<timestamp>.<format>

Registry dumps

/dump registries # Summary of all registries
/dump blocks|items|fluids # Specific registry contents
/dump entities|blockentities # Entity and block entity types
/dump menus|sounds|particles # UI, audio, visual registries
/dump enchantments|effects|potions|attributes

Data-driven dumps

/dump recipes # All recipes
/dump recipes produces <item> # Recipes that output specific item
/dump recipes uses <item> # Recipes that use specific item
/dump tags # All tags
/dump tags reverse [item] # Show what tags an item belongs to
/dump tags contents <tag> # Resolved tag contents
/dump loot # Loot tables
/dump loot resolve <table> # Full loot table definition
/dump advancements # Advancements with requirements

Worldgen dumps

/dump biomes # Biome registry with spawn info
/dump dimensions # Loaded dimensions
/dump spawns # Spawn rules per biome
/dump features # Placed features
/dump structures # Structures and structure sets

Config / state dumps

/dump config # Server configuration snapshot
/dump gamerules # All gamerules with values
/dump datapacks # Enabled datapacks in load order
/dump datapacks overrides <resource> # Which pack affects a resource
/dump mods # Loaded mods with versions
/dump commands # Registered commands

Player dumps

/dump player # Your own player state
/dump player <name> # Specific player's state

Diff tracking

/dump diff enable # Enable tracking for comparisons
/dump diff disable # Disable tracking
/dump diff clear # Clear history
/dump diff # Show tracked categories

Examples

/dump items filter --namespace minecraft --contains stone
/dump recipes filter --type ShapedRecipe --output iron_ingot
/dump spawns filter --contains zombie --format csv
/dump tags filter --namespace forge

Permissions

By default, DumPy requires OP-level permissions (permission level 2) to run dump commands.

Installation

Install like any other NeoForge mod.
Drop the jar into your instance’s mods folder.
Launch, then use /dump help in-game.

License

MIT License.