LibreAI / AI Agents / SimWorld
// agents · SimWorld-AI/SimWorld

SimWorld

SimWorld: an Unreal Engine 5 simulator for evaluating LLM/VLM agents in physical and social worlds.

★ 793 stars⑂ 90 forksApache-2.0updated 2026-06
▦ visual — this project's README ships no embeddable screenshot,
so here's a placeholder. The guide below is complete regardless.
// project facts

Project facts

SimWorld is an open-source ai agents project by SimWorld-AI (SimWorld-AI/SimWorld on GitHub). It has 793 GitHub stars and 90 forks, is released under the Apache-2.0 license, and was last updated on GitHub on 26 June 2026.

GitHub stars
793
Forks
90
License
Apache-2.0
Last updated on GitHub
26 June 2026
Category
AI Agents
Listing
Full install guide
Official site
Official site
// how it works

How it works

  1. Clarify your goal

    Check your hardware against the requirements (dedicated GPU, ample RAM and disk) and decide which environment package you need.

  2. Get the project

    Clone the repository, create a Conda environment, and install the Python client in editable mode.

  3. Install and configure

    Download and extract the Base UE server package for your OS, and optionally add extra map packs.

  4. Run your first task

    Start the UE server, then run an example such as the gym-interface demo so an LLM agent navigates the world.

// features

Why people love it

Unreal Engine 5 backend

Realistic, open-ended environments with accurate physics and a rich asset library for embodied agent research.

Procedural city generation and scene editing

Language-based procedural generation, a city layout generator, and a live asset retrieval and placement editor create varied scenarios.

Gym-like agent interface

LLM/VLM agents receive multimodal observations (including RGB, segmentation, and depth) and act through a local action planner for pedestrians, vehicles, and robots.

Traffic and weather systems

Built-in traffic simulation and weather modules add dynamic, social-world complexity to scenarios.

Tiered environment packages

Start with the lightweight Base package, expand with 100+ pre-built maps, or import your own Unreal environments, assets, and agent models.

YAML configuration system

A single configuration file controls global simulator settings and module behaviour for city generation, traffic, assets, and agents.

Advertisement
// run it

Run it yourself

  1. Clone and install the Python client

    Use Python 3.10 or later in a fresh Conda environment.

    git clone https://github.com/SimWorld-AI/SimWorld.git
    cd SimWorld
    conda create -n simworld python=3.10 && conda activate simworld
    pip install -e .
  2. Download the UE server package

    Get the Base package for your OS from the README's Hugging Face links and extract it. # see README setup section

    # download Base UE server package (Windows or Linux) per README
  3. Start the server and run an example

    Launch the UE server first, then run a Python example from the examples folder.

    ./SimWorld.sh # from the extracted UE server directory on Linux
    # then run an example such as examples/gym_interface_demo.ipynb
// use cases

What you can build

Advertisement
// faq

Questions, answered

Who maintains it?

It is maintained by the SimWorld-AI organisation, with the underlying research presented at venues including NeurIPS and CVPR demo tracks per the README.

Is it free to use?

Yes, SimWorld is Apache-2.0 licensed. The agents you run inside it use your own LLM or VLM access, such as an OpenAI key for the example agent.

Does it need a paid API key?

The simulator itself needs no key, but its LLM/VLM agents call model APIs, so you provide a key for whichever model you plug in.

How does it compare to a well-known alternative?

Simple grid-world or purely text simulators are cheaper to run; SimWorld trades that for Unreal-grade visual realism, physics, and multimodal perception for embodied agents.

How do I get started?

Clone the repo, pip install -e . in a Python 3.10 Conda env, download the Base UE package, start the server, and run an example.

// keep exploring

Similar tools

AI Agents

harbor

A framework for evaluating and improving AI agents.

★ 5.9k starsApache-2.0
View guide →
AI Agents

coze-loop

A full-lifecycle platform for developing, debugging, evaluating and monitoring AI agents.

★ 5.8k starsApache-2.0
View guide →
AI Agents

SimpleMem

Research-backed lifelong memory for LLM agents, text and multimodal.

★ 3.8k starsMIT
View guide →
Agents

agentic-context-engine

Make your agents learn from experience with a dedicated context engine.

★ 2.6k starsApache-2.0
View guide →
AI Agents

A-mem-sys

Agentic memory for LLM agents, from a published research project.

★ 401 starsMIT
View guide →
AI Agents

opik

Open-source LLM observability: trace, evaluate and monitor apps and agents

★ 22.5k starsApache-2.0
View guide →
// alternatives

Alternatives in AI Agents

The most-starred other AI Agents projects in the LibreAI catalogue — the realistic shortlist if SimWorld is not the right fit.

Get SimWorld

Free and open — grab the source, star the repo, and start creating.