Communication Mod
A ModTheSpire mod that launches an external process and talks to it over stdin/stdout, sending game state as JSON and accepting text commands. Most Slay the Spire bots are built on it.
Projects
Interfaces, libraries, bots, simulators and community tools. Status comes from each repository's last commit: active within six months, maintained within eighteen, dormant after that.
53 projects
CommunicationModExtension
Adds socket communication and save/load-state commands to Communication Mod.
LudicrousSpeed
Mod that lets a calling library execute commands in the real game, optionally very quickly, for AI projects.
MCPTheSpire
Slay the Spire mod that runs an MCP server inside the game (Streamable HTTP on port 8080) with tools to read state, play cards, choose options and start runs, so language-model agents can play.
STS2MCP
Slay the Spire 2 mod that exposes game state and actions over a localhost REST API, with an optional MCP server so language-model agents can play. Covers single player and co-op (beta).
STSStateSaver
Mod that saves and loads in-game state, which gives search over the real game a state it can rewind.
SuperFastMode
Speeds up Slay the Spire's animations and delays. Bots playing the real game use it to cut the time per run.
BaseLib
Slay the Spire 2 mod library that standardizes how mods add content. Many STS2 mods list it as a dependency.
BaseMod
Modding API and developer console for Slay the Spire. Communication Mod and most bots list it as a required mod.
ModTemplate-StS2
Project template for starting a Slay the Spire 2 mod.
ModTheSpire
External mod loader for Slay the Spire that loads mod JARs without modifying the game's files. Every STS1 bot stack runs on it.
RitsuLib
Shared framework library for Slay the Spire 2 mods.
STS2 modding tutorials
Work-in-progress tutorials for Slay the Spire 2 modding: setup, BaseLib and RitsuLib, adding content, and visuals. They note that game code still changes often during Early Access.
sts2-mod-uploader
Mega Crit's official tool for packaging Slay the Spire 2 mods and uploading them to the Steam Workshop, configured with a workshop.json file.
spirecomm
Python package that wraps Communication Mod's protocol in game-state objects and actions, with a simple example agent.
AgenticSTS
Research testbed for long-horizon language-model agents on Slay the Spire 2, built around bounded, typed memory instead of a growing transcript. Reports 3/10 wins at Ascension 0 without learned skills and 6/10 with them.
ai-spire
Slay the Spire 2 mod that asks an OpenAI-compatible model (DeepSeek by default) for decisions, adds Spire Codex card data to its prompts, and falls back to a rule engine when the API call fails.
AutoClad
Imitation-learning pipeline on sts_lightspeed: it generates scenarios, records a scripted agent's choices, trains a network to copy them, and exports it for C++ inference. Early work aimed at A20 Ironclad.
Bottled AI
Full-run bot on Communication Mod using hand-built priority lists for choices and a simulated search over hand orderings in combat. The README reports a 52% win rate with its best Watcher strategy.
CombatSolver
In-game combat solver for Slay the Spire 2 single player. It simulates hands, draw piles, enemy intents, potions and relics across turns in the background, then recommends a line or plays it automatically.
LearnTheSpire
Early experiment (2018) training a feed-forward network on local run files to predict which card a player picks, with cards encoded as 1×234 vectors.
slay_the_spire_agent
Knowledge-grounded language-model agent for Slay the Spire on Communication Mod, with an operator dashboard, decision traces and replay.
SlayTheSpireAI
Lets any language model play Slay the Spire through Communication Mod.
STS battle AI (scumthespire)
Combat AI that searches inside the real game, using Communication Mod with STSStateSaver and LudicrousSpeed to try lines and rewind.
STS-AI-Master
Reinforcement-learning decision system for Slay the Spire with headless multi-process training and protobuf messaging between processes.
sts-ironclad-agent
A20 Ironclad bot: one frozen network makes every out-of-combat choice and simulator search plays combat. The README reports a 50.1% Heart win rate over 501 runs in the original game (95% interval 45.7–54.5%).
sts-rl-agent
A0 Ironclad agent: a learned policy handles every out-of-combat choice and sts_lightspeed MCTS plays combat. On 50 held-out seeds it reaches floor 42.5 and wins 14%, against 31.2 and 6% for heuristics.
STS2-Agent
Slay the Spire 2 mod with a local HTTP API, an MCP endpoint and an in-game overlay (F8) that drives any OpenAI-compatible model. It can launch a second game instance where the model plays as your co-op teammate.
sts2-ai-teammate
Mod that adds a local AI teammate so Slay the Spire 2 co-op can be played alone.
sts2-llm
Customization pack that sets up GitHub Copilot as a Slay the Spire 2 player agent, playing through STS2MCP.
sts2-rl-agent
Reinforcement-learning setup for Slay the Spire 2: a Python combat simulator (577 cards, 121 monsters, about 1,200 combats per second per the README), MaskablePPO training, and a C# bridge mod into the real game.
STS2FableBot
Full-run Slay the Spire 2 bot with a deterministic, search-based decision engine, playing through a fork of STS2MCP. The README reports a 20.7% win rate at Ascension 0 over 343 runs and 19.4% at Ascension 1 over 175.
conquer-the-spire
C++17 Slay the Spire simulator covering Ironclad, Silent and Defect cards, intended for reinforcement learning with the PyTorch C++ API.
decapitate-the-spire
Headless Python clone of Slay the Spire made for reinforcement learning and published on PyPI. The README calls it very much a work in progress, focused on Silent in Exordium.
sts_lightspeed
Standalone C++17 reimplementation of Slay the Spire built for tree search, designed to be RNG-accurate. The README reports 1M random playouts in 5 seconds on 16 threads.
sts2-cli
Runs the real Slay the Spire 2 engine headless in a terminal, so damage, card effects, enemy AI, relics and RNG match the game exactly. It needs a Steam copy of the game, and the README says it was tested on v0.111.0.
sts2-sim
Unofficial headless Slay the Spire 2 simulator in C# (.NET 9) against a v0.111.0 baseline. Combat states and RNG streams can be cloned for search. Covers full runs and ascension 0–10.
better-run-logs
Mod that logs every action, potion, choice and RNG state of a run. Useful for building test cases that check a simulator against the real game.
cuda-the-spire
Sieves Slay the Spire seeds on the GPU for properties such as card rewards, map layout and Neow options.
Filter the Spire
Mod that picks seeds before a run so it starts with chosen Neow bonuses, such as a specific boss-relic swap.
RunReplays
Slay the Spire 2 mod that replays a full recorded run, for demos and teaching.
SeedSearch
Runs Slay the Spire headless to search seeds against a configurable filter: rooms, card and relic rewards, events, bosses and Neow options.
Slay the Relics
Twitch extension and game mod that let stream viewers inspect the streamer's deck, relics, potions and powers.
Slay-I (fight predictor)
Neural network trained on over 325,000 fights that predicts damage taken in a fight and scores card picks by damage saved. Shipped as a Steam Workshop mod.
Spire Codex
Database and public API for Slay the Spire 2 (cards, relics, monsters, events and more in 15 languages), built from the game files, plus community run statistics, leaderboards and patch-to-patch diffs.
Spire Codex mod
In-game Slay the Spire 2 companion that shows community win rates in tooltips, helps with map and reward choices, and uploads finished runs to Spire Codex.
Spirescope
Local-first Slay the Spire 2 companion with a card, relic and enemy browser, live run tracker, deck analyzer and overlay mode.
sts_map_oracle
Exact copy of Slay the Spire's map generation: given a seed it prints all three act maps and can export them as JSON.
sts2-advisor
Slay the Spire 2 overlay that recommends cards and relics from community win-rate data.
Orak
Benchmark for training and evaluating language-model agents across 12 video games, Slay the Spire among them, with a public leaderboard.
slay-the-spire-bench
Benchmark of language-model planning on Slay the Spire tasks: turn sequencing, combat, card recognition and Act 1 rollouts, including a comparison of JSON and plain-English prompts.
sts_lean
Models Slay the Spire's card, draw and shuffle rules in Lean 4 to prove which decks have infinite combos. It covers cards and enemy state, not relics or full combat.
typed-decision-slay-the-spire
Benchmark where small language models choose among typed options on the same 200 A0 Ironclad seeds. Nimble-9B averaged floor 14.1 and Laya English 10.4; fine-tuning on a search bot's decisions raised them to 19.5 and 17.1.
Nothing matches those filters.