[DP] DevAssist

In-game datapack profiling and runtime inspection for Fabric servers.

[DP] DevAssist is built for datapack authors, map makers, and technical server operators who need to see what is happening inside a world without leaving Minecraft. It combines a server-side lag profiler with a client-side inspector for entities, markers, display entities, command storage, scoreboards, tags, and raw SNBT.

What It Does

Profiles datapack functions and commands on the server.
Streams compact entity performance snapshots to the client every 5 ticks.
Shows nearby entities within 30 blocks, including invisible entities and vanilla marker entities.
Displays per-entity tick cost, peak MSPT drain, lifecycle, top hot path, and recent tick history.
Provides a full in-game inspector for entity SNBT, scoreboard values, scoreboard tags, and command storage.
Includes raw SNBT editing plus a structured tree view for easier inspection.
Adds searchable text views for SNBT, scoreboards, and storage.
Lets permitted users teleport to or delete inspected entities.
Includes creative noclip while flying, server-authorized, similar to Carpet's creative noclip behavior.

Why Use It

Datapack lag can be hard to diagnose from outside the game. [DP] DevAssist lets you look at the actual entities and functions involved while you are standing in the affected area.

Use it to answer questions like:

Which marker or display entity is causing a spike?
What function path is currently hot?
What changed inside this entity's SNBT?
Which scoreboard values are attached to this entity?
What command storage entries exist and what do they contain?
Is the server MSPT spike global, or tied to a specific entity?

Basic Usage

The default assist key is Left Alt. Hold the assist key to show entity markers and compact runtime information in-world. While holding the assist key, right click an entity marker or targeted entity to open the inspector.

The inspector includes:

Entity list sorted by heat
Server and entity MSPT snapshots
Profiler hot paths
Entity overview
Scoreboard values
Scoreboard tags
Raw SNBT editor
Structured SNBT tree view
Command storage browser and editor

Creative noclip is automatic when permitted by the server: enter creative mode, start flying, and you can pass through blocks. It does not force flying by itself.

Commands

Main command:

/dpdevassist

Short alias:

/dpda

Available subcommands:

/dpdevassist status
/dpdevassist monitor on
/dpdevassist monitor off
/dpdevassist threshold spike <ms>
/dpdevassist threshold command <ms>
/dpdevassist threshold function <ms>

All commands require admin-level command permissions. In singleplayer, the world owner is allowed automatically.

Safety Notes

This is a developer and operator tool. It can edit entity SNBT, scoreboard values, scoreboard tags, command storage, and it can delete entities. Use it carefully on production worlds.

Recommended:

Back up important worlds before editing SNBT or storage.
Test changes in a staging copy first.
Only give access to trusted operators.

Performance Notes

[DP] DevAssist is designed to stay responsive without flooding the client:

Entity summaries sync every 5 ticks.
Full entity SNBT is sent only when requested.
Scoreboard resolution is throttled.
The client renders nearby synced entities and keeps heavy editing views inside the inspector.