The tool-rendering-reasoning-chain demo previously promised chained tool
calls in its pill titles but the agent and fixtures only delivered single
tools — clicking "Weather + flights to Tokyo" produced just a WeatherCard,
"Compare two stocks" only fetched AAPL, "Find flights from SFO to JFK"
showed flights but no destination weather. Three changes close the gap.
Agent: replace the soft "call 2+ tools when relevant" system prompt with
concrete per-pill chain examples mirroring the pattern already used by the
langgraph-typescript `tool-rendering` agent (weather→flights, ticker→peer,
roll→contrast die, flights→destination weather).
Pills: drop the redundant Tokyo pill (it was the SFO/JFK chain in reverse)
and reword each remaining pill message to PRE-DISCLOSE the chain so the
model commits to the follow-up call:
- "Compare AAPL and MSFT stocks for me."
- "Roll a 20-sided die for me and compare it to a smaller one."
- "Find flights from SFO to JFK and show me the weather there."
Fixtures: 9 fixtures (3 per pill: final-content → second-leg → first-leg,
ordered by toolCallId specificity for first-match-wins). Each fixture is
scoped by a langgraph-python-UNIQUE userMessage tail ("Compare AAPL and
MSFT stocks", "compare it to a smaller one", "show me the weather there").
Those substrings appear nowhere else across the 14+ integrations sharing
showcase-aimock on Railway, so the new fixtures cannot cross-contaminate
the other reasoning-chain demos that still ship the older prompt set.
A toolName-based gate was considered and rejected because most fleet
agents register `roll_dice` and aimock's `toolName` matcher is a tool-LIST
gate, not a tool-CALL gate — it would NOT have isolated this demo.
Probe: collapse the two-turn flow (Tokyo + SFO/JFK) into one chained turn
(SFO→JFK + JFK weather) that asserts BOTH per-tool renderers
(FlightListCard + WeatherCard) mount in a single response. Same coverage
at half the wall-clock and exercises the actual chained-tool path.
CopilotKit
Docs · Examples · Copilot Cloud · Discord
Build agent-native applications with generative UI, shared state, and human-in-the-loop workflows.
What is CopilotKit
CopilotKit is a best-in-class SDK for building full-stack agentic applications, Generative UI, and chat applications.
We are the company behind the AG-UI Protocol - adopted by Google, LangChain, AWS, Microsoft, Mastra, PydanticAI, and more!
https://github.com/user-attachments/assets/72b7b4f3-b6e7-460c-a932-5746fe3c8db3
Features:
- Chat UI – A React-based chat interface that supports message streaming, tool calls, and agent responses.
- Backend Tool Rendering – Enables agents to call backend tools that return UI components rendered directly in the client.
- Generative UI – Allows agents to generate and update UI components dynamically at runtime based on user intent and agent state.
- Shared State – A synchronized state layer that both agents and UI components can read from and write to in real time.
- Human-in-the-Loop – Lets agents pause execution to request user input, confirmation, or edits before continuing.
https://github.com/user-attachments/assets/55bf6714-62a7-4d5d-9232-07747cc0763b
Quick Start
New projects:
npx copilotkit@latest create -f <framework>
Existing projects:
npx copilotkit@latest init
https://github.com/user-attachments/assets/7372b27b-8def-40fb-a11d-1f6585f556ad
What this gives you:
- CopilotKit installed – Core packages are fully set up in your app
- Provider configured – Context, state, and hooks ready to use
- Agent <> UI connected – Agents can stream actions and render UI immediately
- Deployment-ready – Your app is ready to deploy
Complete getting started guide →
How it works:
CopilotKit connects your UI, agents, and tools into a single interaction loop.
This enables:
- Agents that ask users for input
- Tools that render UI
- Stateful workflows across steps and sessions
⭐️ useAgent Hook
The useAgent hook is a proper superset of useCoAgent and sits directly on AG-UI, giving more control over the agent connection.
// Programmatically access and control your agents
const { agent } = useAgent({ agentId: "my_agent" });
// Render and update your agent's state
return <div>
<h1>{agent.state.city}</h1>
<button onClick={() => agent.setState({ city: "NYC" })}>
Set City
</button>
</div>
Check out the useAgent docs to learn more.
https://github.com/user-attachments/assets/67928406-8abc-49a1-a851-98018b52174f
Generative UI
Generative UI is a core CopilotKit pattern that allows agents to dynamically render UI as part of their workflow.
https://github.com/user-attachments/assets/3cfacac0-4ffd-457a-96f9-d7951e4ab7b6
Compare the Three Types
Explore:
Generative UI educational repo →
🖥️ AG-UI: The Agent–User Interaction Protocol
Connect agent workflow to user-facing apps, with deep partnerships and 1st-party integrations across the agentic stack—including LangGraph, CrewAI, and more.
npx create-ag-ui-app my-agent-app
🤝 Community
Have questions or need help?
Join our Discord →Read the Docs →
Try Copilot Cloud →
Stay up to date with our latest releases!
Follow us on LinkedIn →Follow us on X →
🙋🏽♂️ Contributing
Thanks for your interest in contributing to CopilotKit! 💜
We value all contributions, whether it's through code, documentation, creating demo apps, or just spreading the word.
Here are a few useful resources to help you get started:
-
For code contributions, CONTRIBUTING.md.
-
For documentation-related contributions, check out the documentation contributions guide.
-
Want to contribute but not sure how? Join our Discord and we'll help you out!
📄 License
This repository's source code is available under the MIT License.