Stored in sessionStorage. Cleared when the tab is closed. Never sent anywhere except api.anthropic.com.
Your proxy must accept POST with the same body as /v1/messages, inject the Anthropic API key server-side,
and stream the response back. See the comment block in the source for a Cloudflare Worker template.
Engine: Streaming responses with prompt caching enabled. Subsequent requests in the same session read from cache.
