KwaiAgents is a series of open-source intelligent agent works from Kuaishou Technology's KwaiKEG. The open-source contents include: KAgentSys-Lite system: A streamlined version of the KAgentSys system in the paper; KAgentLMs series models: Large language models with agent functions such as planning, reflection, and tool usage; KAgentInstruct: Thousands of refined agent instruction data from the paper; KAgentBench: Over 3,000 human-assessed datasets for testing agents' planning, tool usage, reflection, summarization, and descriptive abilities, etc.