Overview
CopilotKit connects to your agents through the Agentic Protocol of your choice
CopilotKit is fully compatible with three major agentic protocols: AG-UI, MCP, and A2A.
Learn about these protocols and how to connect your app to agents which support them using CopilotKit.
Connection | Protocol | Purpose |
|---|---|---|
| Agent ↔ User Interaction | AG-UI (Agent–User Interaction Protocol) | The open, event-based standard that connects agents to user-facing applications — enabling real-time, multimodal, interactive experiences. |
| Agent ↔ Tools & Data | MCP (Model Context Protocol) | Open standard that lets agents securely connect to external systems — tools, workflows, and data sources. |
| Agent ↔ Agent | A2A (Agent to Agent) | Defines how agents coordinate and share work across distributed agentic systems. |
| Agent ↔ Generative UI | A2UI (Google) MCP Apps (MCP Ecosystem) Open-JSON-UI (OpenAI) | Declarative, LLM-friendly generative UI specs that define what to render and how to structure agent responses visually. CopilotKit fully supports all of these. |
Mixing and Matching Protocols#
CopilotKit lets developers connect to any of these protocols directly or in combination. CopilotKit can connect through any of the Interaction Protocols to your agentic backend.
Or, since AG-UI also includes handshakes with both MCP and A2A, CopilotKit can connect to MCP or A2A supporting agents through AG-UI.
This means that if your host agent connects to subagents using MCP or A2A, their UI properties can be propagated all the way through to the user-facing application — while preserving full security, policy, and observability controls.
