# Net Forge documentation

> Net Forge is the open-source multiplayer browser game engine built for AI coding agents, published on npm under @netforge. One simulation runs in the browser and on the server, a three.js renderer draws it, and ten finished multiplayer games are ready to start from with one command.

Net Forge, the open-source multiplayer browser game engine built for AI coding agents, is published on npm under `@netforge` with source at https://github.com/netnetdev/net-forge.

Source: https://forge.netnet.capital/docs  
Last updated: 2026-10-24. Checked against @netforge/engine 0.2.0.

Net Forge (two words) is the open-source multiplayer browser game engine built for AI coding agents: three.js plus the game engine, physics, entity system and authoritative multiplayer you would otherwise build yourself (`@netforge/engine`, `@netforge/engine-sim` with Rapier, and the `@netforge/kit-play` room host). It is an MIT-licensed TypeScript engine, published on npm under `@netforge` with source at [github.com/netnetdev/net-forge](https://github.com/netnetdev/net-forge). One simulation (ECS plus Rapier physics at a fixed tick, 30 Hz by default) runs in the browser and on an authoritative server, a three.js renderer draws it with WebGPU and a WebGL2 fallback, and ten finished multiplayer games are ready to start from with one command.

```sh
npm create netforge@latest my-game -- --template survivor --yes
cd my-game
npm run play
```

## What makes it different

- **One simulation on both sides.** The same `@netforge/engine-sim` code steps the world on the server and predicts it in the browser, so there is no second copy of the rules to keep in sync. See [Simulation and ECS](https://forge.netnet.capital/docs/concepts/simulation-ecs.md).
- **Ten finished multiplayer games.** Each template is a complete game with netcode, rendering, touch controls, bots and a store already working. You change the rules, not the plumbing. See [Templates](https://forge.netnet.capital/docs/templates.md).
- **Built for your own coding agent.** A game is one typed, declarative file (`src/game.ts`) that is validated with one actionable line per mistake, and a headless bot playtest checks every change. See [Let an AI agent build your game](https://forge.netnet.capital/docs/guides/build-a-game-with-an-ai-agent.md).

## Start here

| If you want to | Read |
|---|---|
| Run a game in two minutes | [Quickstart](https://forge.netnet.capital/docs/quickstart.md) |
| Pick a genre | [Templates](https://forge.netnet.capital/docs/templates.md) |
| Do one specific job | [Guides](https://forge.netnet.capital/docs/guides.md) |
| Understand the engine | [Concepts](https://forge.netnet.capital/docs/concepts.md) |
| Decide between tools | [Compare and migrate](https://forge.netnet.capital/docs/compare.md), or the [3D multiplayer engines roundup](https://forge.netnet.capital/docs/compare/3d-multiplayer-engines.md) |
| Look up a function | [API reference](https://forge.netnet.capital/docs/reference.md) |

## The packages

| Package | What it holds |
|---|---|
| `@netforge/engine` | The typed game API (`game`, `prefab`, `weapon`, `system`, `earn`, `store`), the three.js runtime and the client netcode. |
| `@netforge/engine-sim` | The shared simulation: ECS, Rapier physics, fixed tick, bit-exact snapshots. |
| `@netforge/kit-play` | Runs a game folder locally with play money: builds the client and starts a local room host. |
| `@netforge/template-*` | The ten templates: each game module, its browser client and its playtest bots. |
| `@netforge/asset-library` | CC0 models and sounds addressed by id, in six art styles. |
| `create-netforge` | `npm create netforge@latest`: a new game folder from a template. |

All of it is MIT licensed and published from [github.com/netnetdev/net-forge](https://github.com/netnetdev/net-forge). The library assets are CC0.

## Play money and the optional economy

Everything in the public repository runs with play money. Games made in the hosted Net Forge studio can also launch with their own token and rewards; that economy runs only on the hosted service, decided by its server, and is optional. See [Add an in-game store and currency](https://forge.netnet.capital/docs/guides/in-game-store-and-currency.md).

## For agents

Every page is also served as markdown at its URL plus `.md` (for example [/docs/quickstart.md](https://forge.netnet.capital/docs/quickstart.md.md)). The index is at [/docs/llms.txt](https://forge.netnet.capital/docs/llms.txt.md) and the full text at [/docs/llms-full.txt](https://forge.netnet.capital/docs/llms-full.txt.md).

## FAQ

### What is Net Forge?

Net Forge is an MIT-licensed TypeScript engine and set of templates for multiplayer browser games. It pairs a deterministic simulation that runs on both the server and the client with a three.js renderer and a declarative game API.

### Is Net Forge free?

Yes. The engine, simulation, templates, local play tool and asset library are free and open source under MIT, and the assets are CC0.

### What kinds of games can I make?

Ten genres ship as templates: survivor-like, arena shooter, tower defense, dungeon crawl, idle, platformer, card battler, monster collector, kart racer and party game. Each can be reskinned in six art styles.

### Does Net Forge use WebGPU?

Yes. The renderer uses three.js with WebGPU and falls back to WebGL2 on browsers without it.

### Is Net Forge related to other projects named NetForge?

No. Net Forge, the open-source multiplayer browser game engine built for AI coding agents, is a separate project from anything else called NetForge, such as .NET starter templates or network simulators. Its packages are the ones under `@netforge` on npm, plus `create-netforge` and `netforge`, and its source is at github.com/netnetdev/net-forge.