Datapack Debugger
by Alumopper
Datapack Debugger lets a datapack author set breakpoints inside .mcfunction files so the game pauses at a chosen line, which suits debugging command logic on a Fabric client and server.
What it does
A breakpoint is placed by inserting a breakpoint line into a .mcfunction file. When the game reaches it, execution freezes so the state of the world can be inspected, and the rest of the world keeps responding to movement and other commands while the tick is held. Once inspected, the frozen function can be advanced one command at a time, or released to run to the end.
The mod also exposes macro arguments. When a macro function is executed, a breakpoint can read the value of a named argument at the moment the game pauses, which helps when a macro call receives a value that is hard to trace from the code alone. The mod requires Fabric API and runs on Fabric 1.21 only, with its latest file 1.1.1 for 1.21, released 2024-07-24 under the GNU General Public License v3.0 only. The code is not open source under that license's terms as listed by the catalog, and the mod is published for no other game version.
Key features
Breakpoints in functions
A breakpoint line placed in a .mcfunction file freezes the game when execution reaches it.
Step through commands
A frozen function can be advanced one command at a time, so each result can be checked before the next runs.
Continue execution
A paused function can be released to resume normal execution through the rest of its commands.
Read macro arguments
A breakpoint can read the value of a macro argument while a macro function is paused, showing what was passed in.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Just Macros is a Fabric mod for 1.21.4 with a client-side only environment, released under the MIT License and not open source. Chat Macro is also client-side only and covers 1.21 – 26.2 under the MIT License, so it does not change how functions run on a server. Command Profiler is server-side only, open source under the GNU Lesser General Public License v3.0 only, and covers 1.21.9 – 26.3, which makes it a performance tool rather than a pause-and-inspect one.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Datapack Debugger | Fabric | 1.21 | Client and server | 2024-07-24 |
| Just Macros | Fabric | 1.21.4 | Client-side only | 2026-09-01 |
| Chat Macro | Fabric | 1.21 – 26.2 | Client-side only | 2026-08-06 |
| Command Profiler | Fabric | 1.21.9 – 26.3 | Server-side only | 2026-09-06 |
Questions
Does Datapack Debugger need to be installed on the client?
Which loader and game version does Datapack Debugger support?
Does Datapack Debugger require Fabric API?
In the catalog
Datapack Debugger is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 15,770 mods support Minecraft 1.21.
More from Alumopper
Similar mods
What the author says
This is a fabric mod for Minecraft 1.21, which allows you to set breakpoints in the game and "freeze" the game when the breakpoint is reached. In this case, after the game executes say 2, the game will be "frozen" because it meets the breakpoint.
Official listing
- Modrinth page
- modrinth.com/mod/datapack-debugger
- Owner
- Alumopper
- Published
- 2024-07-20
- Updated on Modrinth
- 2024-07-24
- Facts verified
- 2026-10-15