PackTest
by Misode
With PackTest installed on a Fabric server, data pack authors can run game tests from chat and from the command line.
What it does
PackTest is a Fabric mod for testing data packs. It registers test commands that load and run the tests a data pack defines, so a pack's behavior can be checked without manual play. Tests can be run all at once, by namespace, by a given name, or only the ones that failed in the previous run. A test can also be run on every test within 200 blocks of the player.
Test results come from the function a test returns: one function marks the current test as failed, and another marks it as always succeeding. For continuous integration, a system property switches on GitHub annotations, so failed tests and resource load errors appear as annotations in a GitHub Actions run. The author text includes an adapted workflow for that setup.
The mod is server-side only: the server runs the tests, and players joining the server do not need it. It requires Fabric API. Files are published for Fabric across 20 release versions, 1.20.4 – 26.3, and snapshot builds are published as well. The mod is released under the MIT License and is open source, with public source code and an issue tracker.
Key features
Run all tests
A single command runs every test the loaded data packs define.
Run by namespace or name
Tests can be selected by namespace or by a specific test name.
Rerun failed tests
A command reruns only the tests that failed in the previous run.
Nearby tests
Tests within 200 blocks of the player can be run without listing them.
Pass or fail from a function
A test's function can mark the test as failed or as always succeeding.
GitHub annotations
A system property makes failed tests and resource load errors appear as GitHub annotations.
Gallery
Compatibility
Latest build for each game version and loader.
26.x5 of 5 versions with builds
1.21.x12 of 12 versions with builds
1.20.x3 of 3 versions with builds
This mod also publishes snapshot builds. Snapshots are not shown in the matrix.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Who it’s for: Data pack authors and server owners who want automated checks for datapacks. Players who only join a server need nothing installed.
How it compares
Ward is server-side only and open source under the Mozilla Public License 2.0, with files for 26.1.2 – 26.3, so it covers a narrower range than PackTest. MineCaptcha is also server-side only and open source under the MIT License, but it is published for 1.21.8 – 26.2 and does not test data packs. FastSuite [FABRIC] is client-side only and not open source, released under the MIT License for 1.21.1 – 1.21.11.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| PackTest | Fabric | 1.20.4 – 26.3 | Server-side only | 2026-09-20 |
| Ward | Fabric | 26.1.2 – 26.3 | Server-side only | 2026-10-13 |
| MineCaptcha | Fabric | 1.21.8 – 26.2 | Server-side only | 2026-06-16 |
| FastSuite [FABRIC] | Fabric | 1.21.1 – 1.21.11 | Client-side only | 2026-02-25 |
Questions
Does PackTest need Fabric API?
Does a player need PackTest to join a server running it?
Which game versions does PackTest support?
In the catalog
PackTest is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 8,071 mods support Minecraft 26.3.
More from Misode
Similar mods
What the author says
Setting -Dpacktest.auto.annotations will emit GitHub annotations for all test failures and resource load errors. The following example can be adapted into a GitHub action workflow.
Official listing
- Modrinth page
- modrinth.com/mod/packtest
- Owner
- Misode
- Published
- 2023-12-17
- Updated on Modrinth
- 2026-09-20
- Facts verified
- 2026-10-15