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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Home Docs Claude Code CLI 22 Sep 2026
One change · claude-code

Create custom subagents changed

sub-agents

Nearest release: v2.1.280, published an hour before upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Upstream edited this page at 22 Sep 2026 16:49 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 22 Sep 2026 17:07 UTC.

Upstream edited
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From line 420 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits49to this page, all time

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420420* `WaitForMcpServers`
421421* `Workflow`
422422 
423The second filter applies to subagents running in the background. Apart from `Agent` and `ExitPlanMode`, which follow the first filter's conditions wherever the subagent runs, a background subagent keeps every MCP tool but only these built-in tools: `Read`, `Grep`, `Glob`, `Bash`, `PowerShell`, `Edit`, `Write`, `NotebookEdit`, `WebFetch`, `WebSearch`, `TodoWrite`, `Skill`, `ToolSearch`, `EnterWorktree`, `ExitWorktree`, `Monitor`, `TaskStop`, `SendMessage`, and `Artifact`, plus [`SubagentHandback`](/docs/en/tools-reference) for a subagent that reports through it. Claude Code removes every other built-in tool from a background subagent, whether inherited or listed in the `tools` field, so the same definition can resolve to different tools in the foreground and the background. The removal reports no error unless it leaves the `tools` list [resolving to nothing](/docs/en/errors#agent-would-be-spawned-with-zero-tools).
423The second filter applies to subagents running in the background. Apart from `Agent` and `ExitPlanMode`, which follow the first filter's conditions wherever the subagent runs, a background subagent keeps every MCP tool but only these built-in tools: `Read`, `Grep`, `Glob`, `LSP`, `Bash`, `PowerShell`, `Edit`, `Write`, `NotebookEdit`, `WebFetch`, `WebSearch`, `TodoWrite`, `Skill`, `ToolSearch`, `EnterWorktree`, `ExitWorktree`, `Monitor`, `TaskStop`, `SendMessage`, and `Artifact`, plus [`SubagentHandback`](/docs/en/tools-reference) for a subagent that reports through it. Claude Code removes every other built-in tool from a background subagent, whether inherited or listed in the `tools` field, so the same definition can resolve to different tools in the foreground and the background. The removal reports no error unless it leaves the `tools` list [resolving to nothing](/docs/en/errors#agent-would-be-spawned-with-zero-tools).
424 
425Before v2.1.280, background subagents couldn't use `LSP`.
424426 
425427[`ListAgents`](/docs/en/cross-session-messaging) follows these filters like any built-in tool: a foreground subagent inherits it in sessions where cross-session messaging is enabled, and a background subagent doesn't keep it.
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