Change the game.

A SNES-themed desktop companion that lets Astra investigate and alter a running game through natural-language prompts. Built for BizHawk, with an RPG-style interface and live memory tools.

The agent can inspect the actual game, find memory structures, write new memory routines or cartridge patches, test the result, and keep what it learns for that exact cartridge version. The same investigation tools are available for an unrecognized game and a previously unseen request.

This v0.3.2 prototype has passed real Snes9x game-behavior tests and automated Lua/protocol checks. The Windows Lua bridge connection has also been confirmed manually. See validation notes for the scope of these checks.

You need Windows or Linux, Python 3.10 or newer with Tkinter, a current BizHawk release, your ROM, and an OpenAI API key whose project can use gpt-6-astra.

1. Extract this entire folder somewhere writable. Keep its files together.
2. Double-click Start-Windows.cmd, or run python3 run.py on Linux.
3. In BizHawk, open the ROM. Use its BSNES SNES core. Open Tools → Lua Console, then open LOAD-IN-BIZHAWK.lua from this folder.
4. Keep emulation running. The companion will show the cartridge name.
5. Open Settings, enter your API key, and leave the model as gpt-6-astra. Type what you want and click Cast prompt.

This runs alongside the desktop emulator. It is not an iPhone emulator extension and is not a hosted website. The app requires no Python packages beyond the standard library. Linux distributions sometimes package Tkinter separately as python3-tk.

That is the intended workflow. The companion reads the running game, and Lua applies changes between frames. Emulation continues while Astra thinks or researches. A request is not instantaneous: it can require several API calls and observations. Generated ongoing effects execute locally each frame without an API call for each update.

Controlled experiments temporarily run an earlier checkpoint and return to the player's pre-experiment state. They can visibly interrupt play for up to 300 emulated frames per trial. This prototype uses the same emulator for those trials; it does not run a separate invisible emulator in the background.

The live engine behavior has been tested through Snes9x. Native BizHawk and a live Astra request still require an end-to-end desktop test.

Try the original examples in Super Mario World:

• “Drop a star.”
• “Put 5 Chucks on the screen.”
• “Make a new effect that gives me a cape whenever I collect a coin.”

For another game, ask directly for the alteration. Examples of investigation requests include “Find my health and keep it full while I'm playing” or “Figure out how this game stores enemies so we can spawn another one.” These are requests for Astra to investigate, not claims that those behaviors have been tested in every game.

The agent receives:

The general path works without a recognized game profile. Astra can create a new one-shot routine, an effect that runs each frame, or a guarded patch to code/data in the loaded cartridge. The built-in Mario actions provide optional shortcuts.

“Any game, any prompt” describes the interface and investigation goal, not a guarantee of success. The model still has to discover the right structures and verify its reasoning. An unfamiliar game can take multiple requests or need user observations, source notes or additional reverse engineering. Some requests need new assets, more cartridge space, a coprocessor debugger or a larger game engine rewrite. This version can edit existing loaded cartridge bytes; it cannot expand the ROM, create an exportable ROM patch, synthesize new artwork, or debug every special chip. Astra must identify a missing capability or unknown mechanic and report it honestly. No implementation can guarantee every imaginable prompt.

1. Read the screen, ROM identity/header candidates, registers and available domains.
2. Retrieve relevant saved knowledge, imported sources or primary web documentation.
3. Build a working model of the required mechanics: game mode, state fields, object lifecycle, initialization code and graphics dependencies as applicable.
4. Create a checkpoint. Compare a control run with one changed input or candidate alteration. Results include sampled values, WRAM differences and a branch screen.
5. Apply a successful candidate to the live game, verify it, and retain evidence.

Tool evidence is recorded automatically; hypotheses are kept separate from verified findings. Resume resumes saved work, including after restarting the companion. It refreshes live context and never automatically replays an old mutation. The latest bounded tool transcript and a compact working plan are retained; older tool evidence is searchable. The default is 32 API steps per request, adjustable to 1–256 in settings or with --steps.

Add context accepts multiple UTF-8 source/text files, up to 8 MiB each, 32 files and 32 MiB total per ROM. Astra searches them locally and requests relevant excerpts. Lexical search uses keywords, addresses and symbols. It does not upload an entire imported source collection automatically. Game knowledge displays the retained plan, recent evidence and available sources.

Each committed memory mutation gets a full emulator checkpoint. Undo restores the entire game to just before the last mutation, including gameplay since that moment, with the loaded-cartridge byte journal restored as well. Up to eight Undo states and four independent named experiment checkpoints are retained in memory.

Stop effects removes active routines, memory freezes and loaded-cartridge patches. It leaves current WRAM values as they are. Stop thinking prevents the next AI tool operation; it does not undo previous actions. Undo and Stop effects can also be used while Astra is waiting for the API. An in-progress temporary experiment is restored when cancelled. External state/ROM loads supersede the experiment.

Opening another ROM, loading a state externally, or restarting the Lua bridge clears effects and checkpoints. Undo can restore earlier routines and cartridge patches. Your original ROM file is never patched by this app. Cartridge changes are limited to 4096 bytes per operation and 64 KiB of distinct journaled offsets per bridge session; a core must expose writable ROM for these operations.

• ipc/: the connection token, short-lived requests/responses, the latest screenshot and a local cartridge copy for indexing. Start the app before loading the Lua script. Do not run two companion apps against the same folder.
• knowledge/<ROM-SHA1>.json: working context, findings, tool evidence, source metadata and generated routines. Up to 1000 findings and 500 tool events are retained, with bounded excerpts of large tool results.
• knowledge/<ROM-SHA1>.investigation.json: the latest bounded investigation transcript and status, including encrypted API reasoning items for continuation. Screenshots are omitted from the persisted transcript; a fresh one is requested.
• knowledge/sources/<ROM-SHA1>/: locally indexed imported text. Retained context is never executed merely because it exists. Astra decides what to reuse.
• profiles/: optional exact-hash field maps. No manual profile is needed to use the general agent tools.

API keys entered in settings are kept in memory, not written to these files. You can instead set OPENAI_API_KEY; OPENAI_MODEL optionally overrides the model. Prompts, screenshots, requested memory/code windows, notes and selected findings are sent to OpenAI. Full cartridge and RAM dumps are processed locally. Enabling web research also lets Astra send game-related search queries. API usage is billed to the configured OpenAI project; the app shows token counts after a turn.

Run these from the extracted folder:

python run.py --doctor
python run.py --status
python run.py --prompt "Drop a star"
python run.py --prompt "Find the code that updates my health" --no-web
python run.py --prompt "Continue" --steps 64

The explicit Local Mario shortcuts mode needs no API key. It understands a few phrases, including the two original examples, and is useful for checking the emulator connection:

python run.py --local --prompt "Drop a star"
python run.py --local --prompt "Put 5 chucks on the screen"
python run.py --local --prompt "Undo"

The supplied shortcuts accept the unmodified USA SMW SHA-1 and the exact Ice Flower build used for game testing. Other revisions still have the general agent tools. Vanilla sprite slots and level graphics limits still apply: a request for five enemies needs five free slots, and Chucks may have missing or wrong tiles in levels that do not load their graphics.

When loaded-cartridge patches are active, the verified-layout Mario shortcuts are disabled; the general tools remain available to reassess the modified game.

Stop the Lua bridge and companion, then replace their source files together with this version. Preserve your existing knowledge/ directory to keep discoveries; the older notebook format is read automatically. Restart both components. Do not mix files from different releases. Checkpoints exist only in the emulator session.

• If the Lua Console says Open LOAD-IN-BIZHAWK.lua by its full path, replace that launcher with the file from this release. Earlier versions incorrectly assumed BizHawk would expose the script filename through Lua debug information.
• Confirm the app and Lua script came from the same extracted folder.
• Keep BizHawk unpaused, including its background emulation setting when the companion window has focus.
• Check the Lua Console error output. If WRAM is unavailable, select the BSNES core and reopen the ROM and script.
• After a crash, close the crashed companion and remove ipc/client.lock if it remains. Do not remove another running app's lock.
• A timed-out mutation is never automatically repeated: it might have executed before its acknowledgement was lost. Inspect the game or use Undo.
• If Astra's API request is rejected, check the key's project, billing and access to the configured model. There is no automatic substitution of another model.

See CONTRIBUTING.md for development and release instructions, architecture for extension points, and validation for exactly what was tested.

Unit/integration tests require the optional Lua test runtime:

python -m pip install -r requirements-dev.txt
python -m unittest discover -s tests -v

No emulator binary or commercial ROM is included. The small json.lua dependency is included under its MIT license in emulator/json-LICENSE.txt. This project's original source is MIT-licensed; see LICENSE. The Spellbook logo is a separate brand asset; see asset credits.

• BizHawk Lua API
• BizHawk source and releases
• SMW Disassembly X
• GPT-6 Astra model
• Responses function calling
• Responses web search