Skip to content

Supported Environments

All environments implement the PettingZoo parallel API and use discrete action spaces. Experiment notebooks wrap them with a LabelledEnv subclass so reward and focal-agent safety cost are recorded independently.

Environment Matrix

Environment Slug Notebook agents Actions/agent Export includes agents? Safety objective
Congestion congestion 2, 4, 6, or 8 3 Yes A vehicle is unsafe after an adjacent same-slot merge collision.
Gathering gathering 2 by default; configurable ≥2 9 Yes Tagged-out/frozen agent is unsafe.
Markov Stag Hunt markov_stag_hunt 2 5 No A damaged agent is unsafe.
Pursuit Evasion pursuit 2 by notebook default; 2 or 3 supported 5 Yes Unsafe once all intruders occupy goals.
Bertrand bertrand 2 2 No Price-war flag.
Chicken chicken 2 2 No Crash flag.

“Notebook agents” describes the maintained training/export workflows, which may be narrower than the raw class constructor. The full cluster matrix runs Pursuit at two and three agents.

Canonical Classes

Slug Environment Labelled wrapper Safety model
congestion CongestionNetwork LabelledCongestion CongestionSafetyModel
gathering Gathering LabelledGathering GatheringSafetyModel
markov_stag_hunt MarkovStagHunt LabelledMarkovStagHunt MarkovStagHuntSafetyModel
pursuit Pursuit LabelledPursuit PursuitSafetyModel
bertrand BertrandMatrix LabelledBertrand BertrandSafetyModel
chicken ChickenMatrix LabelledChicken ChickenSafetyModel

Agent-Count Consistency

Congestion, Gathering, and Pursuit include n_agents in their canonical export root. Pass the same value to WM, OM, and experiment stages. A graph or opponent checkpoint from another agent count has incompatible state/action dimensions and must not be reused.

Markov Stag Hunt’s raw environment accepts additional agents, but the maintained notebook export root does not include the count. Treat the standard workflow as two-agent unless the notebook/export scheme is extended first.

An earlier matrix-road environment also called Congestion was retired after a fresh safety-first screen. The active congestion slug refers only to the merge-network benchmark above, which passed its five-seed reward--safety gate. Ice Duel, Dynamic Public Goods, Inspection, and the earlier matrix-road implementation remain recoverable from Git history and are maintained as general-purpose environments in rl-engine, but they are not discoverable or launchable from this repository.

Discovery

notebooks.env_discovery discovers classes exported from src.environments and applies the maintained slug, alias, count, and export-path metadata. Use its get_env_spec(...), instantiate_env(...), and export_root(...) helpers in generic notebooks rather than duplicating registries.