Status

esx is in active development. Some areas are not complete yet.

Area	State
Plugin engine and CLI	Works. Records, references, masters, cleaning, conflicts, ESL, copy, diff, merged patch, SEQ and strings.
Fallout 4 definitions	Complete. Some callback differences remain; see docs/porting/notes.
Archives	Works. Read, check, extract and pack for BSA and BA2.
Windows	An automatic test run covers a part of the tests on Windows and on Linux. The game tests and the Creation Kit tools have tests on Linux only.
Load order	Works. Steam, Proton and explicit paths. Native Windows registry lookup is not tested.
Project build	Works. esx build builds a project folder: the plugin, the behavior files, the archives and the release check. Tested on Linux. The Papyrus step has no test with the Creation Kit compiler. On Windows, the before and after commands have no test. See Project and build.
Bulk edits	Work with a Rhai file. Pascal source from xEdit does not run.
Other games	Planned. Starfield asset metadata loads, but its record definitions are not available.
Papyrus	Works. papyrus inspect reads compiled scripts, and plugin check-scripts compares the scripts of a plugin with them. To compile, esx runs the compiler of the Creation Kit. See Papyrus and Creation Kit tools.
Creation Kit tools	Work for the Papyrus compiler, Archive2 and the Spriggit bridge. You install the tools. The tests with the installed tools ran on Linux through Proton. Windows runs the tools directly. That route has a test under Wine, and none on a Windows computer yet.
Weapon animations	Works for weapons that copy a vanilla animation keyword. Variants for seven actions, in first and third person. See Weapon animations.
Game tests	Work on Linux with Proton, for Fallout 4 runtime 1.11.240. An optional F4SE plugin reads ammunition, animation events, clips, graph files, the camera and the player model, and takes screenshots. A test plan runs as one command. You supply F4SE and the Address Library, and you build the plugin DLL. See Game tests.
Meshes and materials	Partial. nif reads Fallout 4 meshes and edits names, paths, node transforms, connect points and furniture markers. material reads and edits each field of a BGSM or BGEM file. esx does not edit geometry, collision or bone weights. See Meshes and materials.
Saves and LOD	Not implemented.

Validation

The tests use synthetic assets, fixtures and an installed Fallout 4. On the Fallout 4 base master:

• A full decode scan reads 1,549,276 records.
• An in-memory round trip reproduces 1,548,613 record bodies byte for byte.
• Definition callbacks change 663 records. There are no other byte differences.

Game tests cover the weapon animation tools and the plugins that they make. The counted reloads of the reference weapon mod run as an automatic test plan with esx probe run. Other areas have no game test yet. Back up your plugins before you edit them.