cs2parser

A fast, typed CS2 demo parser for Node.js, Bun, and modern browsers. Both exports use an embedded WASM Snappy decoder; production installs require no native addons.

Parses .dem files and live HTTP GOTV broadcasts from Counter-Strike 2, providing typed access to entities, players, game events, and more.

Install

npm install cs2parser

Quick Start

import { createReadStream } from 'fs';
import { DemoReader, EntityMode } from 'cs2parser';

const parser = new DemoReader();

parser.gameEvents.on('player_death', event => {
	const attacker = event.attackerPlayer;
	const victim = event.player;
	if (attacker && victim) {
		console.log(`${attacker.name} killed ${victim.name} with ${event.weapon}`);
	}
});

parser.on('end', () => {
	for (const player of parser.playerControllers) {
		console.log(player.name, player.kills, player.deaths, player.position);
	}
});

await parser.parseDemo(createReadStream('path/to/demo.dem'), { entities: EntityMode.ALL });

EntityMode.ALL enables player helpers and full entity state. Use EntityMode.ONLY_GAME_RULES for round events and game rules, or the default EntityMode.NONE when you only need messages and basic player info. Each DemoReader handles one demo or broadcast.

See Parsing demos for supported inputs, completion results, settings, and cancellation.

Browser

Import from cs2parser/browser to parse a file or web stream without Node globals or separate WASM assets:

import { DemoReader, EntityMode } from 'cs2parser/browser';

// file is a File from an <input type="file"> or drag-and-drop.
const parser = new DemoReader();
parser.gameEvents.on('player_death', event => console.log(event.weapon));
await parser.parseDemo(file.stream(), { entities: EntityMode.ALL });

See Browser usage for fetch, metadata, runtime requirements, and WASM Snappy details.

Live HTTP broadcasts

await new DemoReader().parseHttpBroadcast('https://relay.example.com/match-id/', {
	entities: EntityMode.ALL
});

Uses the same events as demo parsing. See Live HTTP broadcasts for relay options, mid-stream joins, and cancellation.

Documentation

Guide	Topics
Parsing demos	Inputs, entity modes, settings, reader state, and cancellation
Pausing and seeking	Tick-boundary playback controls, FullPackets, and seekable sources
Reading metadata	Header, server info, and file info without a full parse
Browser usage	Files, web streams, metadata, and WASM Snappy
Live HTTP broadcasts	GOTV relays, options, descriptors, and wire format
Players and pawns	Rosters, lookups, bot analysis, and helper properties
Entities and match state	Teams, game rules, and typed entity access
Smokes	Seed voxels, density simulation, and visual comparison
Game and parser events	Typed game events and parser lifecycle events
Network messages	Subscriptions, user commands, and message discovery
Encrypted demo chat	Match keys, public chat decryption, and browser support
Development	Entity types, protobuf bindings, and generated registries
Performance	Benchmark commands, methodology, and custom cases
Examples	Runnable scripts and command-line usage

Upgrading from 1.x? See the migration guide.

Acknowledgements

Creating this library wouldn't be possible without awesome work of:

• LaihoE, creator of demoparser
• Saul, creator of demofile-net
• markus-wa, creator of demoinfocs-golang

Huge thanks to all of them, as they all have helped me in some way or the other during the past few years.