Shared State Setup - Copilotkit

<Steps> <Step> ### Put shared state in the system prompt and tools

The demo exposes frontend preferences to Claude and gives the agent a tool
for writing notes back into CopilotKit state. Keep the state contract small,
typed, and mirrored by the UI components that read the same values.

<DemoCode file="src/agents/shared_state_read_write_agent.py" region="shared-state-setup" />

</Step> <Step> ### Register `set_notes` with Claude

This dedicated demo uses the Anthropic Messages API directly. Pass the
schema to `client.messages.stream` so Claude can call `set_notes`.

<DemoCode
  file="src/agents/shared_state_read_write_agent.py"
  region="shared-state-tool-registration"
/>

</Step> <Step> ### Write the tool result back to shared state

When Claude calls `set_notes`, replace the notes array, emit a
`StateSnapshotEvent` for the UI, and return a `ToolCallResultEvent` to
Claude before the loop continues.

<DemoCode
  file="src/agents/shared_state_read_write_agent.py"
  region="shared-state-set-notes"
/>

</Step> <Step> ### Serve the shared-state loop

Mount the dedicated runner on `/shared-state-read-write` and return its
AG-UI events as a streaming response.

<DemoCode
  file="src/agent_server.py"
  region="shared-state-read-write-route"
/>

</Step> </Steps> <Callout type="info"> This Python route intentionally uses its own Messages API loop. It does not use `ClaudeAgentAdapter` or an MCP server. </Callout>