Datapack Sandbox

Run, test, and debug datapacks before shipping

A clean-room local runtime for Minecraft Java datapack authors. Run with the CLI, lock regressions into manifests, and debug interactively in VS Code.

Run a datapack

Write a manifest

View on GitHub

Datapack Sandbox cube and command prompt mark

ONE RUNTIME · THREE WORKFLOWS

Move from an idea to a reproducible test

Use the same deterministic runtime from the terminal, a manifest suite, or your JVM tests. Reports share the same outputs, traces, diagnostics, and snapshots.

01
Load
Read packs and version-specific resource formats.
02
Run
Execute commands, functions, ticks, and player events.
03
Assert
Compare observable output and world state.

manifest regression26.2

$ dps check --strict examples

loading 7 manifests · profile 26.2

PASS generator-output.dps.json

PASS player-events.dps.json

PASS full-stack.dps.json

ALL CHECKS PASSED

4commands2outputs7state changes

DESIGNED FOR TRUST

Fast feedback without pretending to be a server

Datapack Sandbox is intentionally explicit about what it models. Use it for deterministic development feedback, then reserve vanilla integration runs for behavior that genuinely requires the game engine.

Deterministic

Stable seeds, snapshots, and structured reports make failures reproducible.

Inspectable

Every command can expose source locations, output events, traces, and state diffs.

Version-aware

Built-in profiles cover modern datapack formats from 1.20.4 through 26.2.

1. Run a datapack

Use `run` with a pack, function, or single `.mcfunction`, then inspect outputs, traces, and snapshot diffs immediately.

Open the CLI workflow

2. Write a manifest

Combine world fixtures, steps, assertions, version matrices, and coverage thresholds in `.dps.json`.

Lock down a regression

3. Debug in VS Code

Run functions from the editor, inspect traces, keep an active sandbox, or connect the Jupyter kernel.

Configure VS Code

Browser and JVM integration

Embed the Playground, Core, Renderer, or Serve JSONL in websites, test frameworks, and editors.

Choose an integration API