GOAP

GOAP (Goal-Oriented Action Planning) is a form of declarative programming used in artificial intelligence systems. It involves defining a set of actions that can be performed by an agent, each with preconditions and effects, to achieve specified goals within a dynamic environment.

Action planning is made using the A* search algorithm to find the optimal plan of action to achieve the desired state. Performance is improved by using a heuristic function to estimate the cost of each action.

Example

Import the library:

from goap import Action, create_plan

And define the current State of the world as:

initial_state = {
    "music_playing": False,
    "wood_count": 0,
    "has_fire": False,
    "is_warm": False,
}

And the goal we would like to achieve as:

goal_state = {
    "is_warm": True,
}

And then we define a set of possible Actions:

actions = [
    Action("play_the_piano", 3, {}, {"music_playing": True}),
    Action("gather_wood", 2, {}, {"wood_count": 1}),
    Action("build_fire", 1, {"wood_count": 3}, {"has_fire": True}),
    Action("sit_by_fire", 1, {"has_fire": True}, {"is_warm": True}),
]

Note: The Action class takes four arguments: name, cost, preconditions, and effects.

Finally, we can create_plan to find the optimal plan of action to achieve the desired state:

plan, cost = create_plan(goal, actions, initial_state)

This particular example will return the following plan:

Plan found: gather_wood -> gather_wood -> gather_wood -> build_fire -> sit_by_fire | Total Cost: 8

Quickstart

Clone the repository and set the root folder as the current working directory:

git clone https://github.com/FreddyWordingham/GOAP.git goap
cd goap

Install the package using Poetry:

poetry env use python@3.10
poetry install

And then run one of the example scripts:

poetry run python scripts/run.py