MCP Apps: Bring MCP Apps to your users!

Introducing Pydantic AI Integration with AG-UI
By Steven Hartland and Nathan Tarbert
July 23, 2025

Pydantic AI is now natively supported with AG-UI

We’re excited to share that AG‑UI, the open Agent–User Interaction Protocol from CopilotKit, is now natively supported in Pydantic AI, thanks to a new integration built by Steven Hartland at Rocket Science, working hand in hand with the Pydantic AI team.

Why it matters

Pydantic AI is quickly becoming the standard for building reliable, type-safe AI agents in Python. But while the backend agent stack was solid, this integrations now enables first-class UI that improves the users experience:

  • Structured, streaming agent output
  • Live user inputs and corrections
  • Human-in-the-loop checkpoints
  • Frontend tools

That’s exactly what AG‑UI is designed for. It’s a composable protocol that connects AI agents to rich, interactive frontends, with minimal glue and strong separation of concerns.

"We originally began the AG‑UI integration as a standalone library, but with support from the Pydantic AI team, it became clear that this functionality belonged in the framework itself.”
"We collaborated closely with the Pydantic AI team to build in native support for AG‑UI, and shipped it alongside their new toolset abstraction."
  • Steven Hartland - VP Engineering @ Rocket Science

The result is a seamless dev experience:

  • No glue code
  • Streaming agent updates in structured JSON
  • Automatic wiring of tool inputs/outputs to UI state

AG‑UI now works out-of-the-box with Pydantic AI - meaning developers can instantly add structured agent interaction to any AG‑UI-compatible frontend.

What’s next

Rocket Science is very close to using this integration in production, and they’re helping drive AG‑UI forward as an open protocol for building real-time agentic systems.

We’re collaborating closely through the AG‑UI working group, and more patterns, docs, and examples are coming soon, especially around structured editing, tool chaining, and UX for error recovery.

If you're building AI agents in Python and need a clean bridge between backend logic and interactive UI, this integration is built for you.

👉 Try it out: https://ai.pydantic.dev/examples/ag-ui/

👉 Check out the docs: https://ai.pydantic.dev/ag-ui/

Stay up to date and follow @CopilotKit, Pydantic AI, and @rocketsciencegg.

Want to learn more?

Top posts

See All
The Developer's Guide to Generative UI in 2026
Anmol Baranwal and Nathan TarbertJanuary 29, 2026
The Developer's Guide to Generative UI in 2026AI agents have become much better at reasoning and planning. The UI layer has mostly stayed the same, and it is holding back the experience. Most agent experiences still rely on chat, even when the task clearly needs forms, previews, controls, or step-by-step feedback. Generative UI is the idea that allows agents to influence the interface at runtime, so the UI can change as context changes. This is usually done through UI specs like A2UI, Open-JSON-UI, or MCP Apps. We'll break down Generative UI, the three practical patterns, and how CopilotKit supports them (using AG-UI protocol under the hood).
Bring MCP Apps into your OWN app with CopilotKit & AG-UI
Anmol Baranwal and Nathan TarbertJanuary 22, 2026
Bring MCP Apps into your OWN app with CopilotKit & AG-UIToday, we are excited to announce CopilotKit’s support for MCP Apps. Now, MCP servers can finally ship an interactive UI that works out of the box in real agent applications.
How to build a Frontend for LangChain Deep Agents with CopilotKit!
Anmol Baranwal and Nathan TarbertJanuary 20, 2026
How to build a Frontend for LangChain Deep Agents with CopilotKit!LangChain recently introduced Deep Agents: a new way to build structured, multi-agent systems that can plan, delegate, and reason across multiple steps. It comes with built-in planning, a filesystem for context, and subagent spawning. But connecting that agent to a real frontend is still surprisingly hard. Today, we will build a Deep Agents powered job search assistant and connect it to a live Next.js UI with CopilotKit, so the frontend stays in sync with the agent in real time.
Are you ready?

Stay in the know

Subscribe to our blog and get updates on CopilotKit in your inbox.