Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.242 Home All releases olderv2.1.241 v2.1.243newer
Claude Code v2.1.242

Cloud sessions answer each control request with a specific yes, forward, or reason it cannot

You'll notice
Useful3 Signal3
Cloud Sessions

Mid-run changes to a cloud session are either handled, forwarded, or refused with a stated reason.

What

Requests that change a running session (switch model, toggle MCP, rewind, change permission mode) are now routed one of four ways for a cloud session: handled locally, forwarded, forwarded while later sends are held, or rejected with a message naming the reason. Anything anchored to your local machine is rejected rather than silently failing.

Details
  • Handled locally: initialize, interrupt, end_session, cancel_async_message. Forwarded with sends held: set_model, mcp_toggle, rewind_conversation, set_permission_mode and others.
  • Rejected because they name a path on this machine: set_cwd, add_directory, register_repo_root, rewind_files.
  • Also rejected: mcp_set_servers and mcp_message (in-process MCP servers), remote_control, channel_enable, ultrareview_launch, the claude_/mcp_ auth subtypes, set_color, poll_event, stage_file, and agent-originated requests such as can_use_tool, hook_callback and elicitation.
  • Unrecognised request types get a generic "is not supported in a cloud-hosted session" rejection, recorded in telemetry as "unknown".
Evidence

MCP server changes are not available in a cloud-hosted session yet; this machine's MCP servers reach cloud sessions through the device link

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.242 →