CopilotKit Review

CopilotKit describes itself as the horizontal layer between your agents and your users: the same agent can power your web app, mobile app, and your team's Slack or Microsoft Teams workspace. The README lists features: Chat UI with streaming and tool calls, Backend Tool Rendering where agents call backend tools that return UI components rendered in the client, Generative UI where agents create and update components at runtime, Shared State synchronized between agents and UI, Human-in-the-Loop for pausing and requesting confirmation, and Rich Threads that persist across reloads and devices. It is the company behind the AG-UI Protocol, which the README says has been adopted by Google, LangChain, AWS, Microsoft, Mastra, PydanticAI, and others. You get started by handing a prompt to your coding agent that runs npx copilotkit@latest onboard start, install agent skills with npx copilotkit@latest skills install, or scaffold a project with npx copilotkit@latest create. Pricing for CopilotKit Intelligence: Developer is free for one developer (3-day thread retention, 200 threads, 1 GB), Pro is $39 per month, Team is $100 per seat per month for up to 5 seats, and Enterprise is custom; the inspector and frontend SDKs are included in all plans.

The recommended setup is to give your coding agent the onboarding prompt, which inspects your project and guides the integration, or run npx copilotkit@latest create to scaffold a new project in its own directory. There is no server to host for the open-source SDK itself, but your agent backend must be connected through supported agent frameworks. We did not integrate it.

Developers drop in components for chat and generative UI and wire them to agents. The result for end users is an in-app assistant that can render rich components and ask for approval. We did not build with it.

• Chat UI with streaming and tool calls
• Generative UI rendered from agent output
• Shared state between agent and UI
• Human-in-the-loop approvals
• AG-UI protocol support
• Rich Threads and memory through CopilotKit Intelligence
• React, Angular, Vue, React Native, Slack, and Teams

• Covers the frontend half of agent apps that many frameworks ignore
• Open protocol (AG-UI) adopted by several major frameworks according to the README
• Free tier for individual developers
• Popular, about 38,100 stars

• Persistent threads and learning features sit in the paid Intelligence product
• Developer plan retention is only 3 days and 200 threads
• Analytics and Self-Learning are enterprise early access only
• Adds a dependency to your UI layer

The SDK, Inspector, frontend SDKs, and agentic backend connections are included in every plan. CopilotKit Intelligence: Developer is free forever for one developer (3-day retention, 200 threads, 1 GB, 1 Slack or Teams org); Pro is $39 per month (5-day retention, 5,000 threads, 10 GB); Team is $100 per seat per month for up to 5 seats (14-day retention, 25,000 threads, 100 GB); Enterprise is custom. Cloud hosting is included in all plans, and VPC or on-prem is optional on Team.

The Vercel AI SDK focuses on streaming text and tool calls to React UIs from your backend. CopilotKit covers more of the agent-to-UI layer, such as shared state, generative UI, and human-in-the-loop, and adds a hosted layer for persistent threads.

• Teams adding an in-app copilot to a web product
• Developers building agent UIs across frameworks
• Projects that want agents available in Slack and Teams too

• Simple chat widgets that need only streaming text
• Teams that want to avoid a company-led protocol
• Projects needing long thread retention without paying