OpenEnv

Connect4 Environment

A classic Connect Four board game environment for training agents on turn-based strategy with a 6×7 grid. Players alternate dropping pieces into columns, aiming to connect four in a row horizontally, vertically, or diagonally.

Quick Start

import asyncio
from connect4_env import Connect4Action, Connect4Env

async def main():
    async with Connect4Env(base_url="http://localhost:8000") as client:
        obs = await client.reset()
        print(f"Board: {obs.board}")
        print(f"Legal moves: {obs.legal_actions}")

        # Drop a piece in column 3
        result = await client.step(Connect4Action(column=3))
        print(f"Reward: {result.reward}, Done: {result.done}")

asyncio.run(main())

Action Space

Field	Type	Description
`column`	`int`	Column index (0–6) where the piece will be dropped

Invalid moves (out-of-range or full column) result in a reward of -1 and end the episode.

Observation Space

Field	Type	Description
`board`	`list[list[int]]`	6×7 grid — `1` = current player, `-1` = opponent, `0` = empty
`legal_actions`	`list[int]`	Column indices that are valid moves

Rewards

Outcome	Reward
Win (4 in a row)	`+1.0`
Draw (board full)	`0.0`
Invalid move	`-1.0`
Otherwise	`0.0`

State

Field	Type	Description
`episode_id`	`str`	Unique ID for the current game
`board`	`list[list[int]]`	Current board state
`next_player`	`int`	Whose turn it is (`1` or `-1`)
`step_count`	`int`	Number of steps taken

Update on GitHub