What it does

Sims 4 Mod Folder Steward is for players whose Mods folder has grown past the point of sorting by hand. It checks the folder, proposes a plan, and only changes files once the whole plan is approved. Every change can be undone.

The desktop app has one window and three pages. Start finds the usual Mods folder by itself and accepts a dropped folder, an optional Inbox, a ZIP, a .package or a .ts4script. Check results shows only three groups: Safe to handle, Needs your approval, and Leave for now. The technical evidence stays inside expandable details. Confirm & recover reviews the totals, offers a complete Mods backup with a space estimate, asks for one approval of the whole plan, then opens the result or undoes the run.

Unknown current files stay where they are. Unknown Inbox files stay in the run’s review area and are not installed. The same engine is available from a command line (s4mod scan, run, run --apply, undo) for terminal and agent users, with a dry run by default.

The app switches between English and Simplified Chinese while it runs, and the README and guides ship in both languages.

Safety rules

  • A read-only scan before every plan.
  • Installing, replacing and organising files need approval of the whole plan.
  • Replaced originals are quarantined before the new file is installed.
  • Hash and path checks run immediately before every operation and every Undo.
  • No permanent deletion, and no reads or writes in Saves.
  • No network access, login, AI API, MCP, automatic download or plugin system.

For help from an AI assistant, the app exports one ZIP of anonymised reports with a prepared prompt. It never contacts an AI service itself, and no mod contents go into that ZIP. Anything an assistant suggests downloading still has to come back through the local planner and executor.

What I worked on

I worked on the product definition and engineering: the three-page workflow, the planner and executor, the safety rules, the bilingual interface and the packaging, using AI-assisted development. The main design decision was to reduce a technical scan to three answers a player can act on, and to keep the evidence one click away instead of on the first screen.

What has been checked

The repository’s test workflow runs pytest and ruff on Ubuntu, Windows and macOS with Python 3.11, 3.12 and 3.13. It passed on the 21 October 2026 snapshot (54272f6). The tests cover scanning, planning, execution, archives, backups, the command line, the GUI, localisation, path handling and privacy, and they use synthetic bytes only: no real mods, paid content or user inventories are in the repository.

A separate workflow builds the Windows and macOS apps; its last recorded run, on 3 August 2026, succeeded. The screens in the case study are the real app, rendered off-screen on a sample Mods folder.

What remains unproven

This is a beta candidate. The README asks people to try it on a test copy before trusting it with an important Mods library, and these checks don’t establish behaviour on every real collection of mods or how players get on with it. Development builds are unsigned, so the operating system will warn before opening them. It is an unofficial fan-made utility, not affiliated with Electronic Arts, Maxis or The Sims.

The public repository holds the code, the bilingual guides and the safety notes. The case study in RIRRI’S replays a sample run: four files, three answers, one approval.