[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.