continual-foragax 0.33.2

A continual reinforcement learning benchmark

foragax

Foragax is a lightweight, JAX-first grid-world environment suite for continual / procedural experiments. It provides a small collection of environment variants (weather, multi-biome, etc.), a registry factory for easy construction, and simple example scripts for plotting and visualization.

This version is a Gymnax environment implemented in JAX. The original implementation of Forager is implemented in Numba is available at andnp/forager. In addition to the original features, this implementation includes: biomes, visualization, and a weather environment.

Key ideas:

• Functional, JAX-friendly API (explicit PRNG keys, immutable env state objects).
• Multiple observation modalities: Object and RGB, as well as aperture based or full-world observations.
• Customizable biomes
• Customizable object placement, respawning, and rewards.
• Visualization via RGB rendering and plotting.

Quickstart

We recommend installing with pip from https://pypi.org/project/continual-foragax/.

pip install continual-foragax

We support Python 3.8 through Python 3.13.

The codebase expects JAX and other numeric dependencies. If you don't have JAX installed, see the JAX install instructions for your platform; the project uv.lock pins compatible versions.

Minimal example (from examples)

Use the registry factory to create an environment and run it with JAX-style RNG keys and an explicit environment state.

from foragax.registry import make
import jax

# create env (observation_type is one of: 'object', 'rgb', 'world')
env = make(
		"ForagaxWeather-v1",
		aperture_size=5,
		observation_type="object",
)

# environment parameters and RNG
env_params = env.default_params
key = jax.random.key(0)
key, key_reset = jax.random.split(key)

# reset returns (obs, env_state)
_, env_state = env.reset(key_reset, env_params)

# sampling an action and stepping (functional-style)
key, key_act, key_step = jax.random.split(key, 3)
action = env.action_space(env_params).sample(key_act)
_, next_env_state, reward, done, info = env.step(key_step, env_state, action, env_params)

# rendering supports multiple modes: 'world' and 'aperture'
frame = env.render(env_state, env_params, render_mode="aperture")

See examples/plot.py and examples/visualize.py for runnable scripts that produce a sample plot and saved videos using Gym/Gymnasium helpers.

Registry and included environments

Use foragax.registry.make to construct environments by id. Example environment ids include:

• ForagaxTwoBiomeSmall-v1 / -v2 — hand-crafted small multi-biome layouts
• ForagaxWeather-v1 — small weather-driven two-biome environment used by examples

The make factory accepts the following notable kwargs:

• observation_type: one of "object", "rgb", or "world".
• aperture_size: integer or tuple controlling the agent's local observation aperture.
• file_index: used to pick weather locations.

Custom objects and extensions

The codebase includes an object system for placing items into biomes and controlling behaviour (rewards, respawn / regen behavior, blocking/collectable flags). See foragax.objects for the canonical object definitions and helpers like create_weather_objects used by the registry.

If you want to add new object classes, follow the examples in foragax.objects and add the class into registry configs or construct environments programmatically.

Design notes

• JAX-first: RNG keys and immutable env state are passed explicitly so environments can be stepped inside JIT/pmapped loops if desired.
• Small, composable environment variants are provided through the registry (easy to add more).

Examples

• examples/plot.py — runs a short random policy in ForagaxWeather-v1 and produces a temperature vs reward plot (saves to plots/sample_plot.png).
• examples/visualize.py — runs environments at multiple aperture sizes and saves short videos under videos/ using save_video.

Development

Run unit tests via pytest.

Acknowledgments

We acknowledge the data providers in the ECA&D project. Klein Tank, A.M.G. and Coauthors, 2002. Daily dataset of 20th-century surface air temperature and precipitation series for the European Climate Assessment. Int. J. of Climatol., 22, 1441-1453.

Data and metadata available at https://www.ecad.eu