CopilotKit is a platform for building agentic applications where an AI agent acts inside the user's product. It connects agent frameworks to user-facing apps through an open protocol, with ready-made UI components or headless APIs.

Agent-to-user connection - an open protocol linking agentic backends such as OpenAI Agents SDK, Claude Agent SDK, LangChain, Google ADK, and Mastra to any frontend.
Frontend SDKs - React, Angular, Vue, iOS, Android, Slack, Teams, and WhatsApp surfaces.
Generative UI - agents render charts, forms, and approvals with the product's own components.
In-app actions and shared state - agents take action through APIs and keep state in sync with the app.
Learning loop - interactions become signals that improve the agent, with analytics on runs, outcomes, and tool calls.
Self-hosting - run the open-source SDK and runtime on your own infrastructure or use the managed cloud.

It is used by product and engineering teams embedding support, knowledge, and workflow agents directly into their applications.