Cloudflare Agents 0.27.0 adds Web Search and new harnesses, including containers that can run Claude Code or Codex

What changed

Cloudflare released Agents 0.27.0 on October 7. The stable package adds AiSdkHarness, ThinkHarness, ContainerHarness and OpenCodeHarness. ContainerHarness can run agent CLIs such as Claude Code or Codex inside Cloudflare Containers while Durable Objects manage sessions, recovery and persistent state. The release also adds agents/websearch, exposing Cloudflare's Web Search API as a web_search tool for Pi, the AI SDK and TanStack AI. Channels moves to experimental/channels around a rebuilt conversation-and-turn model, with a Web Channel, terminal TUI, and fixes across MCP credentials, Streams and reconnection. The new harnesses and Channels APIs are explicitly experimental and may change.