dfhack-remote-node

dfhack-remote-node

A small, strictly-typed Node client for the DFHack Remote RPC protocol — protobuf over raw TCP (127.0.0.1:5000). It lets a Node process read from (and, later, act on) a live Dwarf Fortress fort without compiling against DFHack's C++.

This is a TypeScript port of the original browser client (alexchandel/dfhack-remote, ISC). The protocol codec is carried over; the transport was rewritten from WebSocket + websockify to Node net.Socket, RunCommand console output is now captured instead of discarded, and methods bind lazily on first use.

Built primarily as the RPC layer for a DFHack MCP server.

Install

npm install dfhack-remote-node

The published package ships prebuilt (dist/ ESM + type declarations, proto bundle inlined), so no build step is needed to consume it.

To work on the library from a clone instead:

npm install
npm run build     # regenerates build/proto.json and bundles dist/

build/proto.json (the compiled protobuf bundle) is committed, so the source runs immediately; npm run build produces the distributable dist/ (ESM + type declarations, with the proto bundle inlined).

Usage

import { DwarfClient } from 'dfhack-remote-node';

const df = new DwarfClient(); // defaults to 127.0.0.1:5000
await df.connect(); // handshake

console.log(await df.getVersion()); // DFHack version string
const world = await df.getWorldInfo(); // decoded GetWorldInfoOut
console.log(world.worldName?.englishName);

// Arbitrary Lua snippet; returns whatever it prints (captured console output):
const text = await df.runLuaSnippet('print(#df.global.world.units.active)');

// Any method in the METHODS table, by name:
const map = await df.call('GetMapInfo');

df.close();

Every reply object also carries _text — the concatenated console output from any TEXT frames the call produced.

Package layout

src/ is split by concern (all TypeScript ESM):

File	Responsibility
codec.ts	wire framing: magic bytes, frame ids, encodeMessage, readHandshake, readFrame
errors.ts	RpcError, ProtocolError
connection.ts	DfConnection — the net.Socket transport + call queue
methods.ts	the METHODS table (fully-qualified protobuf type names)
proto.ts	loads the committed proto bundle as a JSON module import
client.ts	DwarfClient — the high-level API
index.ts	public exports

The source imports the proto bundle as a JSON module (import protoJson from '../build/proto.json' with { type: 'json' }), so the bundler inlines it into dist/ — there is no runtime file lookup.

Protos

The .proto files are pinned to DFHack 53.15-r2 (pulled from DFHack/dfhack at the commit the running build reports via getGitDescription). To retarget another version, replace the files from the matching tag and re-run npm run gen-proto. Method input/output types in METHODS (src/methods.ts) are fully-qualified names that must match DFHack's registration, or BindMethod reports a "wrong signature" at runtime — which makes drift detectable per method.

Scripts

npm run build       # gen-proto + tsup -> dist/ (ESM + .d.ts, proto inlined)
npm run gen-proto   # regenerate build/proto.json from proto/*.proto
npm run typecheck   # tsc --noEmit
npm run lint        # eslint (flat config)
npm run format      # prettier --write
npm test            # offline: mock server speaks the real wire format, no game needed
npm run spike       # live: connect to a running fort, print version + world + fort name

npm test validates handshake, framing, lazy binding, protobuf round-trip, and TEXT-frame capture against an in-process mock. npm run spike (M0) requires Dwarf Fortress running with DFHack and a fort loaded.

Protocol notes

• Handshake: client sends DFHack?\n + i32(1), server replies DFHack!\n + i32(1).
• Message header: id:i16, pad:u16, size:i32 (little-endian), then size body bytes.
• A call's reply is zero or more TEXT frames (console output) followed by one RESULT frame (reply protobuf) or one FAIL frame (errno in the size field).
• Calls are serialized — DFHack handles one at a time per socket.
• GetBlockList only returns blocks changed since the last call — don't build a full-map snapshot on it naively (use ResetMapHashes to force a resend).

Contributing

Issues and PRs welcome. Please keep the module boundaries above intact, run npm run typecheck, npm run lint, and npm test before opening a PR, and add new RPC methods to src/methods.ts with their fully-qualified protobuf type names. Changes touching the live protocol should be verified against a running fort with npm run spike.

License

ISC. Ported from alexchandel/dfhack-remote (Copyright © 2020 Alexander Chandel); the original copyright and license are preserved in LICENSE.md.