1 · Choose a pack

Drop your pack's .zip here or press Enter or tap to pick a file

A .zip data pack or resource pack, or a folder of Mythic configs zipped up. You can choose several at once and they are reported together.

Or paste a link to a pack on ModrinthNew

2 · How deeply to check

The structural, layout, reference and lint checks always run. The deeper layers need Minecraft's own generated data, which is a few megabytes and is fetched once, then cached by your browser. Whatever you choose, the report states plainly which layers ran and which did not — a check that was skipped is never reported as a pass.

Command grammar — parse every .mcfunction line against Mojang's command tree 3.1 MB JSON schemas — check the contents of loot tables, predicates, recipes and the rest 2.5 MB Mythic registry — mechanic, condition and targeter names, for MythicMobs server packs 120 KB

Report from Treat as

3 · Check it

Loading the checker…

Run these checks from an AI assistantClaude, ChatGPT and Gemini can use MCDDD too. Step-by-step setup →

Same checks, on the command line

This page and the command-line tool run the identical checking core, so they cannot disagree. For CI, use the command line: it exits non-zero on findings and can write machine-readable JSON. Download mcddd.zip (no unzipping, no dependencies) and run it with Python 3:

PYTHONPATH=mcddd.zip python -m mcddd check ./my_pack
PYTHONPATH=mcddd.zip python -m mcddd check ./my_pack --format json --require-complete

On Windows, in Command Prompt run set PYTHONPATH=mcddd.zip first; in PowerShell run $env:PYTHONPATH="mcddd.zip". Then python -m mcddd check my_pack.

MCDDD · runs on Pyodide

1 · Choose a pack

2 · How deeply to check

3 · Check it

Report

Passed — badge earned

Same checks, on the command line