WASM Chasm

WASM Chasm

You could just bookmark your MSFS 2024 WASM folder and delete things by hand. Honestly, that works fine. WASM Chasm is for people who'd rather press a few keys and watch aircraft WASM files fall into a chasm.

Pick the aircraft, press Enter, and off they go into the WASM Chasm.

What it does:

• Lists your aircraft by their proper names where it can find them (otherwise by package ID)
• Removes the compiled WASM files the sim made, which the sim rebuilds next time
• Keeps each aircraft's work folder by default, because that's where add-on settings and licence files can live
• Sends everything to the Recycle Bin, so you can get it back
• Has a dry run option that shows what would be removed without touching anything
• Checks the sim isn't running before it deletes anything

Yes, the retro terminal is completely unnecessary. A plain window would do the same job. But it was fun to make, so why not?

If you'd rather skip the theatre of Fun mode, there's a Serious mode: no animation, no sound, one plain font. Both modes do exactly the same thing to your files, and you can switch with F4. See Using it.

It's free, with no installer, no telemetry, no network access and no admin rights. For Windows, Steam or Microsoft Store.

Not affiliated with Microsoft, Asobo Studio or any aircraft developer.

By default WASM Chasm removes only the compiled files the sim generated, and keeps the work folder. The sim rebuilds those files.

Warning: purging an aircraft's work folder is a separate, stronger option. It erases that aircraft's own settings and saved state, and anything add-on tools stored there — for example installed navdata, a SimBrief alias, a Hoppie ID, or licence and activation files. You may need to re-enter, reinstall or reactivate them. Everything goes to the Recycle Bin by default so you can restore it.

Download

The first releases are pre-releases. The app hasn't been tried on a real Steam install. If you use Steam, please run it with dry run on first and tell me in Issues whether it found your install. See Status.

Get it only from the repository's Releases page. It is one small zip with the exe inside, for 64-bit Windows 10 or 11, with nothing to install. Each release includes SHA256SUMS.txt, so you can check your download in PowerShell:

Get-FileHash wasm-chasm-win-x64.zip -Algorithm SHA256

The app isn't code-signed at the moment, so Windows SmartScreen may warn you when you first run it.

Where WASM data lives

A package folder holds two different things:

Using it

Fun and Serious: the app asks which you want the first time it runs. Fun is the retro look, with animations and optional sound. Serious is the same app without any of that: one plain font at one size. It only changes how the app looks and sounds, never what happens to your files. The choice is remembered, and F4 switches at any time.

Settings (F3): CRT effects on/off, sound on/off (Fun only, and off by default; a gentle hum, a power-up at launch, a soft blip as you move, a rising ratchet as you mark aircraft, a crumble and a chime), disposal method (Recycle Bin — default; zip backup then Recycle Bin; permanent delete), backup folder (paste or type its path), scope (compiled cache only — default; work folder only; or whole package folder) and dry run.

Dry run shows what would be removed and touches nothing. In Fun it plays the same fall into the chasm, and the rows return afterwards.

More than five aircraft at once requires typing Y to confirm.

After a purge: Serious always shows a results page. Fun skips it after a clean purge and shows a one-line summary instead, because each row falling into the chasm has already shown its folder is done. Fun still shows the results page after a dry run, if animations are off, if a link was removed, if a backup was written, and whenever anything was skipped or failed.

The gauge beside the chasm shows how much data you have marked. A full bar means all the data that could be purged.

Aircraft are listed by the title in their manifest.json. If it can't be found, for example because an add-on manager has unlinked the aircraft or the sim streams it, the list shows the package ID instead.

Safety

• Every target path is canonicalised and must sit inside the detected WASM root (at least two levels down), and no ancestor between the root and the target may be a link. Anything else is refused.
• Symlinks and junctions are never followed: if a work folder is a link (Addons Linker and similar), only the link is removed and the result says so.
• The sim (FlightSimulator2024.exe) is checked before the run and before every folder. If it starts mid-run, the rest are skipped.
• A locked or access-denied folder is skipped and reported; there are no retries and no elevation.
• If the Recycle Bin is disabled or too small, you're asked: zip a backup first and then delete, or cancel. Nothing is ever silently deleted permanently. The check uses the drive the data is really on, even when a moved Store install reaches it through a junction.
• Each session is appended to %LOCALAPPDATA%\WasmChasm\wasmchasm.log. Settings are kept beside it in settings.json.