ClaudePlaysTheSpire - Watch ChatGPT and Friends Think and Climb the Spire

HermesBridge — Let an AI Play Slay the Spire 2

Watch it live: twitch.tv/ClaudePlaysTheSpire

What this is
HermesBridge exposes Slay the Spire 2's run state to an external process so an LLM (or any program) can play the game. The mod writes the current game state to a file every tick and reads queued actions back. No HTTP, no sockets — just two files on disk and a polling loop.
That's it on the mod side. The intelligence lives in whatever you point at it.

How it works

• state.json — written every game tick. Contains hand, deck, monsters, map, rewards, potions, energy, HP, relics, current screen, available actions.
• actions.jsonl — append-only command queue. Drop a JSON line, the mod consumes and executes it next tick.
• A driver script — reads state, decides what to do, writes actions. The included PowerShell helper (autopilot-lib.ps1) shows the pattern; any language works.

The included SKILL.md is the real product — a behavioral spec teaching an LLM how to play through the bridge without falling into the named failure modes (hand-index shifts after PlayCard, multi-Proceed Rewards→Map flow, post-potion stat lag, etc.). It's the distilled output of multi-hour autopilot runs with frontier models.

Requirements

• BaseLib — required dependency. Install first.
• Slay the Spire 2 v0.103.2 or compatible.
• Frontier-tier LLM — the autopilot workflow has been validated only on Claude Opus 4.7-class models. Weaker models repeatedly fail in characteristic ways (writing wrapper scripts instead of per-tick driving, ignoring SKILL.md constraints, energy-math errors). The bridge itself is model-agnostic; the autopilot SKILL is not.

Install

1. Install BaseLib.
2. Extract this archive into <Slay the Spire 2 install>/mods/. You should end up with mods/HermesBridge/HermesBridge.dll.
3. Launch the game. The bridge starts writing state.json to the mod folder.
4. See INSTALL.txt and docs/hermes-sts2-runbook.md for driver setup.

What's in the package

• HermesBridge/ — the mod (drop into mods folder)
• SKILL.md — autopilot behavioral spec
• autopilot-lib.ps1 — PowerShell driver helpers
• docs/bridge-protocol-notes.md — state.json / actions.jsonl reference
• docs/hermes-sts2-runbook.md — operator runbook
• docs/example-run-necrobinder.md — annotated successful run
• README.md, INSTALL.txt, LICENSE (MIT)

Status
Early / experimental. Singleplayer only. Used in production on the Twitch stream. Source on GitHub: github.com/hiKareeem/ClaudePlaysTheSpire.

Links

• Twitch: twitch.tv/ClaudePlaysTheSpire
• GitHub: github.com/hiKareeem/ClaudePlaysTheSpire
• Issues / feedback: GitHub Issues

Credits
Built on BaseLib by Alchyr. MIT licensed.