Fields of Mistria Mods & MOMI Installer Guide

Last checked: August 27, 2026. The game had a major engine change on July 7, 2026, so an older mod should not be assumed compatible. Check each mod against the current loader and release notes before installing it.

Before installing mods

Back up your save, close the game, and record which mods you enable. That makes a broken update or incompatible mod reversible. Use the official MOMI repository and official Releases page as the source for the installer.

MOMI release channels

The visible GitHub status checked on August 27, 2026 was:

• v0.13.3: Latest stable release, released July 18, 2026.
• v0.14.3 Beta 9: visible current pre-release, released July 29, 2026.

Use stable for the least experimental path, or choose the clearly labelled beta only when you have a reason to test it. MOMI is actively developed, so return to the official Releases page for the newest build instead of assuming this snapshot stays current.

Install and manage a mod

On Windows:

1. Download MOMI from the official release channel.
2. Run the installer.
3. If the game is not detected, place the installer near the game directory / Maybe.toml area as appropriate.
4. Click Install.
5. Create a folder named mods in the game directory, at the same level as FieldsOfMistria.exe.
6. Extract each mod into that folder and follow the mod's own manifest instructions.

For Steam Deck / Linux, supported locations include the mods folder inside the game directory or a home-directory folder named mistria-mods. The game must be closed while changing files. After a game update, rerun MOMI when required.

Manifest files and common errors

Current MMAPI documentation supports a mod manifest in either manifest.json or manifest.toml; it does not require TOML every time. Use the MMAPI Manifest documentation when a mod's README and installer behavior disagree.

If a mod does not load, check these first:

• the ZIP was actually extracted
• there is no extra nested folder layer
• the manifest can be found where the mod expects it
• the game directory is correct
• the mod is compatible with the current engine and MOMI version

If the issue began after a game update, disable the newest mod first, restore the backup if needed, and check the official release page before reinstalling. See the platform availability guide for the verified Steam Deck / Linux support boundary.