autism-mcp

MCP server + Fabric addon that let an AI agent drive and observe AUTISM Client (Minecraft 26.2) for exploit-hunting research on local test servers: run a controlled experiment, observe state and packets before and after, record a reproducible finding.

Safety model

• Default and intended target: a local Paper or Fabric server you stand up yourself.
• allowed_targets in config.toml (default 127.0.0.1, localhost). Both the MCP server and the addon refuse to connect, chat, run commands, interact, or send packets against anything else.
• The bridge binds 127.0.0.1 only and requires a random per-session token in a chmod 600 file. Off by default — enable the MCP Bridge module in the client.
• Packet tools are rate-limited (hard cap 100/s), experiments have packet/time caps. No flooding, no telemetry, no upload. Findings stay in local files.
• No account/credential handling. Use an offline throwaway account.

Requirements

Linux, Java 25, Node 20+, a Prism Launcher instance of AUTISM Client on Minecraft 26.2 (the client has no headless mode — it runs on your display). No root needed.

Setup

You bring your own local test server (Paper or Fabric, 127.0.0.1 or another address listed in config.toml's allowed_targets). tests/ has optional helper scripts (server-start.sh, server-stop.sh, world-backup.sh, world-restore.sh) for a disposable local Paper instance if you'd rather not set one up by hand; scripts/e2e.sh itself doesn't call them.

git clone <this repo> && cd autism-mcp          # the client checkout must sit next to it: ../Autism-Client
scripts/build-all.sh                            # client API -> ~/.m2, addon jar, mcp-server build
PRISM_INSTANCE=<your-instance> scripts/install-addon.sh

1. Edit config.toml: point [bridge] dir at <prism instance>/minecraft/autism-mcp, and set allowed_targets to wherever your test server runs.
2. Start your test server. Join it offline-mode with an offline throwaway account.
3. PRISM_INSTANCE=<your-instance> scripts/run-client.sh, log in the same way, enable the MCP Bridge module in the client's module menu.
4. Register the MCP server with your agent, e.g. in .mcp.json:

{ "mcpServers": { "autism": { "command": "node", "args": ["/abs/path/autism-mcp/mcp-server/dist/index.js"],
  "env": { "AUTISM_MCP_ROOT": "/abs/path/autism-mcp" } } } }

Tools

All tools return JSON {ok, data | error:{code,message}, tick}.

Group	Tools
Session	mc_status, mc_connect, mc_disconnect, mc_wait_ticks, mc_wait_for
Observe	mc_get_state, mc_get_inventory, mc_get_screen, mc_get_entities, mc_get_blocks, mc_get_block, mc_get_chat
Act	mc_look, mc_set_input, mc_use_item, mc_attack, mc_interact_block, mc_interact_entity, mc_click_slot, mc_close_screen, mc_drop, mc_swap_hands, mc_select_slot, mc_chat, mc_command, mc_teleport_via_command
Modules	mc_list_modules, mc_get_module_settings, mc_toggle_module, mc_set_module_setting
Packets	mc_packet_capture_start/stop/get, mc_packet_send, mc_packet_delay, mc_packet_drop
Research loop	mc_experiment_start/snapshot/diff/stop, mc_finding_record/list/get/replay, mc_reset_world_state

Not implemented, on purpose: screenshots (no clean client API), macro list/run (no public entry point in the client's macro system), S2C packet delay/drop (receive listeners can't cancel).

Tests

cd mcp-server && npm test     # MCP layer against a mock bridge
scripts/e2e.sh                # real client + your own test server; launch the client from Prism when prompted

License

GPL-3.0-only (see LICENSE); the addon links against AUTISM Client, which is GPL-3.0.