---
id: engines/mesa
about:
  label: Mesa
  description: >-
    Open-source Python library for building agent-based models, with grids,
    networks, data collection and a browser view; Mesa-Geo adds maps, so agents
    can live in real geography loaded from GIS files.
  tags:
    - agent-based
    - Python
    - simulation framework
    - GIS
    - teaching
tool:
  form: open-source Python library
  group: People and populations
  homepage: 'https://mesa.readthedocs.io/stable/'
  licence: Apache-2.0
  cost: free
domains:
  - people
  - places
open:
  source: open
  data: open
  api: 'yes'
  participation: open
  licence: Apache-2.0
relations:
  - predicate: alternative_to
    target: engines/netlogo
  - predicate: alternative_to
    target: engines/gama
provenance:
  origin: agent
  sources:
    - title: Mesa documentation
      url: 'https://mesa.readthedocs.io/stable/'
    - title: mesa/mesa (README)
      url: 'https://github.com/mesa/mesa'
    - title: mesa/mesa-geo (README)
      url: 'https://github.com/mesa/mesa-geo'
    - title: 'Mesa 3: Agent-based modeling with Python in 2025 (Crossref record)'
      url: 'https://api.crossref.org/works/10.21105/joss.07668'
    - title: mesa/mesa releases
      url: 'https://github.com/mesa/mesa/releases'
    - title: mesa/mesa commit history
      url: 'https://github.com/mesa/mesa/commits/main'
  created: '2026-10-23'
  reviewed: '2026-10-23'
  reviewed_by: 'Claude, from the sources listed'
  status: draft
---
Mesa is a toolkit for writing agent-based models in Python. An agent-based model describes individuals, people, animals or firms, and the rules each follows, then runs them together to see what patterns emerge from their interaction. Mesa supplies the common parts: agents and a way to step them, spaces such as grids and networks, tools to record each step, and an interactive view in a web browser or a Jupyter notebook.[^1,2] The project presents it as the Python alternative to NetLogo, Repast and MASON.[^2]

It is an open-source project that welcomes contributions.[^1] The paper describing version 3, by Ewout ter Hoeven and six co-authors, appeared in the Journal of Open Source Software in March 2025.[^1,4] Version 3.5.1 came out in March 2026, version 4 is in pre-release, and the project is very active, with commits in October 2026.[^5,6] It takes part in Google Summer of Code.[^1,2]

The same project makes Mesa-Geo, which adds a geographic space. Its agents carry a real geometry, a Shapely shape, with a coordinate reference system, and can be loaded from shapefiles, GeoJSON or GeoPandas tables.[^3] With it, agents can stand on real streets and parcels instead of an abstract grid.

Both install with pip.[^2,3] Models are plain Python, so they can use Python's data tools for input and analysis.[^1] Mesa ships with no population or disease of its own; everything specific to a place has to be built by the modeller. For a visual, lower-code start, see [NetLogo](/engines/netlogo/); for a platform built around GIS from the outset, see [GAMA](/engines/gama/). Mesa and Mesa-Geo are Apache-2.0.[^2,3]