Youtu-Agent is a modular framework designed for building and running autonomous agents. It emphasizes flexibility and extensibility, allowing developers to create tailored agents, tools, and environments. The framework separates its core components to facilitate robust agent development, which includes defining agents, environments, and toolkits for actions, all of which can be evaluated using a dedicated Evaluation Framework. The architecture consists of several key modules. Configuration is managed through a system that utilizes pydantic and hydra with YAML files to dictate agent behavior and experiment settings. Two main agent paradigms are supported: SimpleAgent, which operates in a loop, and OrchestraAgent, which coordinates multiple agents through a Plan-and-Execute strategy. Environments provide context and state for agents, with various options like ShellLocalEnv for filesystem tasks and BrowserEnv for web interactions. Toolkits offer pre-built capabilities for tasks such as web searches and document analysis. The Evaluation Framework is crucial for assessing agent performance, featuring a structured pipeline for data management, processing, and execution. It allows for automatic benchmarking, ensuring that performance metrics are consistent and reliable. For those interested in getting started, a Quickstart Guide is available to help set up the necessary environment and run the first agent efficiently.