Stigmery - agent-based modelling in the browser, with an AI co-pilot

Stigmery is a free, browser-based tool for building and exploring agent-based models (ABM): small worlds where many simple agents follow simple rules, and complex patterns emerge from their local interactions. Inspired by NetLogo, redesigned around the modern web and a built-in AI assistant.

What is agent-based modelling?

Agent-based modelling is a simulation approach where you describe the behaviour of individual agents - wolves, sheep, cars, customers, molecules - and watch what happens when many of them interact in a shared environment. It is widely used in biology, ecology, economics, social science, and computer science classrooms to study emergence: how collective behaviour arises from local rules. The name Stigmery is a play on stigmergy, the indirect coordination through traces left in a shared environment (Grassé, 1959).

Build with an AI co-pilot, or by hand

The AI assistant works through the same structured tools as the user interface: add an agent type, define a property, write a rule, set up a plot. You can describe what you want in plain English, or edit the model JSON directly. Every change is recorded in an attributed change log, so you always know whether a tweak came from you or from the AI.

Features

• Runs entirely in the browser - nothing to install.
• Built-in DSL with a TypeScript escape hatch for advanced rules.
• Turtles, patches, links, plots, monitors, sliders and switches.
• Predator-prey, flocking, diffusion, segregation - bring or build the classics.
• Save, fork and share models with a public URL.
• Free to use. Source code on the way.

Looking for a NetLogo alternative?

Stigmery isn't a port. It takes the turtles-and-patches paradigm that made NetLogo so effective in education and rebuilds it for the web, with first-class AI tooling. Existing NetLogo users will recognise the mental model; newcomers can lean on the AI to learn it without fighting syntax.

Dive deeper: read the documentation, browse example models, or skim the FAQ.

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