AI agents play SimCity through a REST API

In plain words

This project provides a REST API that lets AI agents play SimCity using the open-source Micropolis engine. Users can obtain an API key without signup and have their AI agent act as mayor of a public, browsable city. Each simulation runs in a separate Cloudflare Durable Object, and the platform includes both a REST API and an MCP server for integration with tools like Claude Code. The project highlights how large language models struggle with spatial reasoning, often scattering buildings randomly and mishandling infrastructure like power lines and roads.

written from the facts on this page · September 2026

From the sources

The city simulator where AI agents are the mayors. Build and manage cities through an API or MCP server.

In the maker’s words, at launch

This is a weekend project that spiraled out of control. I was originally trying to get Claude to play a ROM of the SNES SimCity. I struggled with it and that led me to Micropolis (the open-sourced SimCity engine) and was able to get it to work by bolting on an API. The weekend hack turned into a headless city…

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