Overview
The Built-in Agent is CopilotKit's simplest agent option, i.e what you get "built-in". It connects directly to an LLM with full support for tools, generative UI, shared state, and all CopilotKit features — without requiring an external agent framework.
It supports most popular models from OpenAI, Anthropic, Google, and AI-SDK defined models out of the box
When to use Built-in Agent
- Quick setup — no external agent framework to configure or deploy
- Chat + tools — your use case is primarily conversational with frontend and server tools
- Direct model access — you want to use OpenAI, Anthropic, Google, or AI-SDK models directly
Info
If you need more control over your agent loop, consider using an agent framework instead.
Features
Generative UI
Render rich React components in the chat.
Frontend Tools
Let the agent interact with your UI using frontend tools.
Server Tools
Define backend tools with Zod schemas that the agent can invoke.
MCP Servers
Connect MCP servers for extended tool capabilities.
Shared State
Bidirectional state sharing between your app and the agent.
Model Selection
Choose from OpenAI, Anthropic, and Google models — or bring your own.
Agent Context
Share app-specific context with the agent automatically.
Advanced Configuration
Fine-tune temperature, tool choice, multi-step calling, and more.
Getting Started
Head to the Quickstart to set up a working Built-in Agent in minutes.