Tools gain a backgrounding setting controlling whether they can keep running in the background
Many built-in tools — including WebFetch, WebSearch, Bash, Task, PowerShell, MCP (Model Context Protocol) tools, and various read-only lookup tools — now carry a backgrounding property set to one of three values: "detach", "self", or "never". Tools without a value default to "never". A new internal check looks at whether a tool's backgrounding is "detach" to decide if that tool call is allowed to keep running in the background, with its result delivered later through a separate message once it finishes.
This lays the groundwork for certain tools to run in the background instead of blocking the conversation while they complete, letting Claude Code (and the user) continue working while a long-running tool call finishes elsewhere.
The finding does not say which tools are actually marked as detach-capable versus self or never, or when background results become visible…