Slay the Spire 2 · modding tool

STS2 Mod Uploader UI

A local web dashboard for publishing & updating your Slay the Spire 2 mods to the Steam Workshop — review everything, fix the thumbnail, preview BBCode, and upload in one click.

View on GitHub How to run

MIT licensed Python · stdlib + Pillow Windows · Steam EN / 한국어

127.0.0.1:8791 — STS2 Steam Workshop Upload

My Skin Modv0.19.0 · 2h ago●

Map Tweaksv0.2.1 · 1d ago⟳

Speed Sliderv0.1.0 · unpublished

RNG Fixv0.1.1 · 3d ago●

thumbnail

My Skin Mod v0.19.0

✔ Title set
✔ Description set (BBCode)
✔ Thumbnail set (under 1 MB)
✔ Content to upload
✔ Workshop item linked

✔ Ready to publish

UploadBuild + Upload

This runs on your own machine. Steam Workshop uploads go through your local Steam client, so there is no hosted "upload from a website" — like every Steam mod uploader, you run it locally and it publishes under your Steam account, with your mods. This page is just the intro; grab it from GitHub and run it yourself.

What it does

Scans your mods/ folder

Auto-detects your Steam install and lists every installed mod. No config needed to get started.

Registration checklist

See at a glance whether the title, description, thumbnail, content and Workshop item are set — before you publish.

Thumbnail, handled

Pick any image; it is auto-converted to PNG and shrunk under Steam's 1 MB preview limit.

BBCode with live preview

Write your description with insert buttons and an Edit / Preview toggle that renders it the way Steam will.

Update detection

When a mod's version changes, a ⟳ badge shows the deployed → current diff and pre-fills the change note.

One-click upload

Packages the installed mod (skipping runtime junk) and runs the official uploader, streaming the log live.

Run it locally

Get the official uploader. Download ModUploader-win-x64 and put the folder next to the script (or point config.json / STS2_UPLOADER_DIR at it).
Get this tool. git clone https://github.com/ing-gom/sts2-mod-uploader-ui

Install Pillow & run.

pip install pillow
python workshop_dashboard.py

Open the dashboard at the printed URL (default http://127.0.0.1:8791), pick a mod, fill it in, and upload. Start with private, verify on Steam, then switch to public.

Requirements

Windows with Steam running and logged in (the uploader uses the Steam client — it can't run headless).
Python 3.8+ and Pillow (pip install pillow) for thumbnail processing.
The official STS2 mod uploader (ModUploader.exe + steam_api64.dll + steam_appid.txt).

Full setup, configuration and gotchas are in the README (English & 한국어).