Under the hoodTier: how much it should matter to you
3Useful: my rating, 1 to 5
4Signal: worth watching, 1 to 5
MCPArea: what it touches
Internal ChangesKind: in v2.1.288,
What probably matters to youSection of the release
What
Claude Code now recognises a control message called mcp_tasks_changed. MCP (Model Context Protocol) is the way Claude Code connects to outside tools, and the message name suggests it reports a change in tasks from those tools.
A host, meaning a program driving Claude Code, is not allowed to send this message. If one tries, it is refused with the error "mcp_tasks_changed is sent to a cloud agent by the service, not by a host", the same rule that already covered stage_file and turn_handoff. Claude Code also registers a handler for the message when it does arrive.
Why
This looks like groundwork for the service to notify cloud agents about MCP task changes. Programs that host Claude Code cannot use it.
Read from
Names in the bundlemcp_tasks_changed
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtWhat Claude Code does on receiving this message, and who sends it, were not established.
