@kar-mi/spirit-vale-tools-capture

Passive Windows packet capture and Spirit Vale protocol decoding for Bun.

Install

bun add @kar-mi/spirit-vale-tools-capture

Exports

• @kar-mi/spirit-vale-tools-capture — protocol decoding types and helpers
• @kar-mi/spirit-vale-tools-capture/capture — passive packet capture (requires Npcap)
• @kar-mi/spirit-vale-tools-capture/wire-reader — FishNet wire-format reader

Usage

import { PacketCapture, getNpcapStatus } from "@kar-mi/spirit-vale-tools-capture/capture";

const status = await getNpcapStatus();
if (status.availability !== "ready") throw new Error("Npcap is not ready");

const capture = new PacketCapture();
capture.on("fishNetPacket", (packet) => {
  console.log(packet.tick, packet.packetName);
});

await capture.start({
  protocols: ["udp"],
  targetProcessName: "SpiritVale.exe",
  decodeFishNet: true,
});

Import from /capture only in a Bun main process; it exposes the Windows Npcap APIs. The package root exports the pure protocol decoders (decodeLiteNetLibDatagram, decodeFishNetBundle, FishNetSessionDecoder) for replay and testing without a live capture.

Eternal Tower state

FishNetEternalTowerTracker consumes decoded capture packets and exposes the best-known tower name, floor, and instance information:

import { FishNetEternalTowerTracker } from "@kar-mi/spirit-vale-tools-capture";

const tower = new FishNetEternalTowerTracker();
capture.on("fishNetPacket", (packet) => {
  if (!tower.consume(packet)) return;
  const state = tower.current();
  console.log(state.known, state.inTower, state.towerName, state.floor, state.instanceId);
});

known remains false until either a DrawTitle banner matching "<tower name>\nFloor <n>" or a ClientInstancedMapReady with bindingSlot === "et" arrives. The former supplies towerName and floor; the latter confirms tower entry and can supply instanceId and instancedMapId. The tracker preserves tower state across reconnects because the server may not repeat either signal when reattaching to the same floor. A non-tower ClientInstancedMapReady clears the state.

The assembly-derived RPC map still registers PlayerController.ETUpdateRun and ETAdvanceFloor at wire hashes 95 and 96, but observed Eternal Tower captures contain no invocations of either method. Registration proves that the methods remain in the build; it does not prove that the server calls them.

See the package guide for registry setup and usage.