What
Claude gets written instructions for each tool it can use. Two of them, for running commands in the background with run_in_background, now change depending on a check:
- Bash: when the check is false, the description of
run_in_backgroundno longer promises you will be notified when the command finishes. It ends with a different sentence instead:Only use this if you don't need the result immediately. - PowerShell: the advice about
Start-Sleep,run_in_backgroundand polling is only included when a check for background support passes. Before, it was always included.
Why
Claude should stop being told to rely on background running or completion notices in setups where they do not apply.
Names in the bundlerun_in_background
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on Orchestrate teams of Claude Code sessions touched a line naming run_in_background after this was published.
* **No background subagents from in-process teammates**: an in-process teammate's own subagents run in the foreground, because a teammate's background work can't outlive the lead's process. Claude Code returns an error when a teammate spaw…agent-teams see the edit
Confirmed since
Anthropic's documentation has since written up run_in_background, on Agent SDK reference - TypeScript.
Notification when a background task completes, fails, or is stopped. Background tasks include `run_in_background` Bash commands, [Monitor](#monitor) watches, and background subagents. For the `run_id` and `ambient` fields, see [`SDKTaskSta…agent-sdk/typescript see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up run_in_background, on Agent SDK reference - TypeScript.