PAAMS 2023 - MAIN TRACK -- Brain waves classification using a single-channel dry EEG headset: an application for controlling an intelligent wheelchair -- AJAN: An Engineering Framework for Semantic Web-Enabled Agents and Multi-Agent Systems -- Adaptive consumption by continuous negotiation -- When Extrinsic Payoffs meet Intrinsic Expectations -- Multi-Agent Reinforcement Learning for Structured Symbolic Music Generation -- A multi-level density-based crowd simulation architecture -- Resolving the Dilemma of Responsibility in Multi-Agent Flow Networks -- Lessons Learned on the Design of a Predictive Agent for LoRaWAN Network Planning -- A solution concept with an exploration bias for repeated stochastic coalitional games -- Governing online forum interactions with multi-agent system: A Reddit use case with the JaCaMo platform -- Fuzzy Hyperplane based Twin-KSVC and Its Applications to Stock Price Movement Direction Prediction Based on News Articles -- Enhancing Safety Checking Coverage withMulti-swarm Particle Swarm Optimization -- A Decentralized Resource Allocation Protocol in Social Networks -- Multi-agent learning of causal networks in the Internet of Things -- Investigation of Integrating Solution Techniques for Lifelong MAPD Problem Considering Endpoints -- Towards Norm Entrepreneurship in Agent Societies -- Velluscinum: A Middleware for Using Digital Assets in Multi-Agent Systems -- Parking Problem with Multiple Gates -- UAV Swarm Control and Coordination Using Jason BDI Agents on top of ROS -- Traffic Assignment Optimization using Flow-based Multi-Maps -- A Monitoring Agent for Advancing Elderly Care through Mobile Health Technology -- Extrinsic Emotion Regulation by Intelligent Agents: A computational model based on Arousal-Valence dimensions -- Optimization of Complex Systems in Photonics by Multi-Agent Robotic Control -- GTG-CoL: A new Decentralized Federated Learning based on Consenssus for dynamic networks -- A novel framework for multi-agent knowledge-based federated learning systems -- Exploring Planner-Guided Swarms Running on Real Robots -- Integrating Policy Summaries with Reward Decomposition for Explaining Reinforcement Learning Agents -- A Multi-Agent Based Dynamic Network Slice Tarification Framework -- An IDE to Support the Development of Embedded Multi-Agent Systems. Bioinspired Artificial Cockroach Colony Strategy combined with 2-type Fuzzy Logic for the Priority-Based Sanitization of Railway Stations -- Embedding Autonomous Agents into Low-Power Wireless Sensor Networks -- Safe Autonomous Decision-Making with vGOAL -- PAAMS 2023 - DEMONSTRATIONS -- Towards Exception Handling in the SARL Agent Platform -- Multi-Agent Path Finding for Indoor Quadcopters -- Energy community integration of a smart home based on an open source multiagent system -- Cognitive Assistant for Enhanced eHealth Monitoring -- Extended Green Cloud - Modeling Cloud Infrastructure with Green Energy Sources.

This book constitutes the proceedings of the 21st International Conference on Practical Applications of Agents and Multi-Agent Systems, PAAMS 2023, held in Guimaraes, Portugal, in July 2023. The 32 full papers in this book were reviewed and selected from 70 submissions. 5 demonstration papers are also included in this volume. The papers deal with the application and validation of agent-based models, methods, and technologies in a number of key applications areas, including: advanced models and learning, agent-based programming, decision-making, education and social interactions, formal and theoretic models, health and safety, mobility and the city, swarms and task allocation.