🚀 ABTree

Asynchronous behavior tree framework built on Python asyncio, designed for intelligent decision systems with declarative programming paradigm

中文 | English

---

📑 Table of Contents

• ✨ Core Features
• 🎬 Quick Start
• 📖 Documentation
• 🔧 Technology Stack
• 🗺️ Roadmap
• 🤝 Contributing
• 📜 License

---

✨ Core Features

🚀 Async Engine	🎯 Node System	💾 Data Management	🌲 Behavior Forest
Based on asyncio High Performance Concurrency	Rich Node Types Dynamic Registration	Blackboard System Event Driven	Multi-tree Collaboration Internal & External Communication

⚡ Asynchronous Behavior Tree Engine

• High Performance Async Execution - Concurrent node scheduling based on Python asyncio
• Smart Tick Management - Automated execution cycle management and resource control
• Event Driven Architecture - Asynchronous event dispatcher supporting real-time response
• Memory Optimization - Efficient state management and garbage collection

🎯 Rich Node System

• Composite Nodes - Sequence, Selector, Parallel and other classic control flows
• Decorator Nodes - Inverter, Repeater, UntilSuccess and other behavior modifiers
• Action Nodes - Action, Log, Wait, SetBlackboard and other execution units
• Condition Nodes - Condition, CheckBlackboard, Compare and other judgment logic
• Dynamic Registration - Runtime node type registration and extension mechanism

💾 Smart Data Management

• Blackboard System - Cross-node data sharing and state persistence
• Event Dispatcher - Asynchronous event listening, publishing and subscription mechanism
• State Management - Complete tracking of behavior tree execution state
• Data Validation - Type-safe data access and modification

🌲 Behavior Forest Collaboration

• Multi-tree Coordination - Multiple behavior trees working together as a forest
• Communication Modes - Pub/Sub, Req/Resp, Shared Blackboard, State Monitoring, Behavior Invocation, Task Board, External IO
• Forest Management - Centralized forest configuration and lifecycle management
• Performance Monitoring - Real-time performance analysis and optimization suggestions

---

🎬 Quick Start

🔧 Environment Setup

Development Environment Installation

For source code development, debugging, and contributing:

git clone https://github.com/xiongwc/abtree.git
cd abtree
pip install -e .

Production Environment Installation

For production deployment and daily use:

pip install abtree

📝 Basic Usage

🚀 Method 1: Programmatic Building

import asyncio
from abtree import BehaviorTree, Sequence, Selector, Action, Condition
from abtree.core import Status

# Define action nodes
class OpenDoor(Action):
    async def execute(self):
        print("Opening door")
        return Status.SUCCESS

class CloseDoor(Action):
    async def execute(self):
        print("Closing door")
        return Status.SUCCESS

# Define condition nodes
class IsDoorOpen(Condition):
    async def evaluate(self):
        return self.blackboard.get("door_open", False)

# Build behavior tree
root = Selector("Robot Decision")
root.add_child(Sequence("Door Control Sequence"))
root.children[0].add_child(IsDoorOpen("Check Door Status"))
root.children[0].add_child(CloseDoor("Close Door"))

# Create behavior tree instance
tree = BehaviorTree()
tree.load_from_node(root)

# Execute
async def main():
    blackboard = tree.blackboard
    blackboard.set("door_open", True)
    
    result = await tree.tick()
    print(f"Execution result: {result}")

asyncio.run(main())

📄 Method 2: Declarative XML Configuration

import asyncio
from abtree import load_from_xml_string

# Declarative XML: Express behavior logic in a readable, structured format
xml_string = '''
<BehaviorTree name="Robot Decision">
    <Sequence name="Door Control Sequence">
        <CheckBlackboard name="Check Door Status" key="door_open" expected_value="true" />
        <Log name="Close Door Log" message="Door detected open, preparing to close" />
        <Wait name="Close Door Wait" duration="1.0" />
    </Sequence>
</BehaviorTree>'''

# Load behavior tree from declarative XML configuration
tree = load_from_xml_string(xml_string)

# Execute
async def main():
    blackboard = tree.blackboard
    blackboard.set("door_open", True)
    
    result = await tree.tick()
    print(f"Execution result: {result}")

asyncio.run(main())

🌲 Behavior Forest Example

import asyncio
from abtree import (
    BehaviorForest, ForestNode, ForestNodeType,
    BehaviorTree, Sequence, Selector, Action, Condition
)
from abtree.core import Status

# Simple robot action node
class RobotAction(Action):
    def __init__(self, name: str, action_type: str):
        super().__init__(name)
        self.action_type = action_type
    
    async def execute(self):
        print(f"Robot {self.action_type}")
        if self.action_type == "cleaning":
            self.blackboard.set("cleaning_needed", False)
        return Status.SUCCESS

# Simple condition node
class SimpleCondition(Condition):
    def __init__(self, name: str, key: str, default: bool = True):
        super().__init__(name)
        self.key = key
        self.default = default
    
    async def evaluate(self):
        return self.blackboard.get(self.key, self.default)

def create_robot_tree(robot_id: str) -> BehaviorTree:
    """Create a simple robot behavior tree"""
    root = Selector(f"Robot_{robot_id}")
    
    # Cleaning sequence
    cleaning_seq = Sequence("Cleaning")
    cleaning_seq.add_child(SimpleCondition("Check Cleaning", "cleaning_needed"))
    cleaning_seq.add_child(RobotAction("Clean", "cleaning"))
    cleaning_seq.add_child(RobotAction("Navigate", "navigating"))
    root.add_child(cleaning_seq)
    
    tree = BehaviorTree()
    tree.load_from_node(root)
    return tree

async def main():
    # Create behavior forest
    forest = BehaviorForest("Robot Forest")    

    # Add robot nodes
    for robot_id in ["R1", "R2", "R3"]:
        tree = create_robot_tree(robot_id)
        node = ForestNode(
            name=f"Robot_{robot_id}",
            tree=tree,
            node_type=ForestNodeType.WORKER,
            capabilities={"cleaning", "navigation"}
        )
        forest.add_node(node)
    
    # Start forest
    await forest.start()
    
    # Execute ticks
    for i in range(3):
        results = await forest.tick()
        print(f"Tick {i+1}: {results}")
        await asyncio.sleep(0.5)
    
    await forest.stop()

if __name__ == "__main__":
    asyncio.run(main())

---

📖 Documentation

• 📚 Quick Start: examples/
• 🔧 API Reference: docs/api.md
• 🛠️ CLI Tools: cli/
• 🧪 Testing: tests/

📁 Project Structure

abtree/
├── abtree/                     # 📦 Core package
│   ├── core/                   # 🔧 Core functionality
│   ├── engine/                 # ⚙️ Engine system
│   ├── forest/                 # 🌲 Behavior forest
│   ├── nodes/                  # 🎯 Node implementations
│   ├── parser/                 # 📝 Configuration parsing
│   ├── registry/               # 📋 Node registration
│   └── utils/                  # 🔧 Utilities
├── cli/                        # 🖥️ Command line tools
├── docs/                       # 📖 Documentation
├── examples/                   # 📚 Example code
├── tests/                      # 🧪 Test suite
├── scripts/                    # 📜 Script tools
├── test_reports/               # 📊 Test reports
└── pyproject.toml              # ⚙️ Build and dependency configuration

---

🔧 Technology Stack

Component	Technology	Version
Language	Python	3.8+
Async Framework	asyncio	Built-in
XML Processing	xml.etree	Built-in
Testing	pytest	7.0+
Type Checking	mypy	1.0+

---

🗺️ Roadmap

• ✅ v0.1 - Core asynchronous behavior tree framework
• ✅ v0.2 - XML configuration support
• ✅ v0.3 - event dispatcher and blackboard optimization
• 🎯 v0.4 - Advanced node types
• 🤖 v0.5 - ROS2 integration support

---

🤝 Contributing

1. Fork the project repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

---

🙏 Acknowledgments

Inspiration from BehaviorTree.CPP.

---

📜 License

This project is licensed under the MIT License.

---

⭐ If this project helps you, please give us a Star to support development! ⭐