Subagent Forking Now On by Default

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Subagent Forking Now On by Default

A forked subagent now inherits the full conversation and prompt cache, so it starts with your session's context instead of a cold start. Non-teammate agent spawns in interactive sessions also run in the background by default now, keeping your main session free while they work.

Worth Knowing

Mention Other Sessions by Name With @

You can now type @ in the prompt to mention another live Claude session by name, and Claude uses SendMessage to reach it directly. Sessions on the same machine also keep unique names now, getting a name-word-word variant when a name collides.

Todo Tools Removed From Newer Models

The TodoWrite and Task tracking tools are no longer available on Opus 4.8, Sonnet 5, Fable 5, Mythos 5, and newer models. If you rely on them, set CLAUDE_CODE_ENABLE_TODO_TOOLS=1 to restore them.

GitLab Support Across Worktrees and Marketplaces

The --worktree flag and the claude agents view now handle GitLab merge request URLs, showing MRs as !N. Bare gitlab.com repo URLs, including nested subgroups, also clone as plugin marketplaces the same way github.com URLs do.

Cap Bash Command Memory on Linux

You can now set CLAUDE_CODE_TOOL_MEMORY_LIMIT on Linux to cap the memory a Bash tool command can use, so a runaway build can't stall your session.

Write Tool Relaxes Read Requirement

Newer models can now overwrite an existing file with the Write tool without having read it first this session, matching the Edit tool's behavior. Older models still require the read.

Under the Hood

Multiple Permission and Sandbox Bypasses Closed

This week patched several permission bypasses, including an NT \??\ device-prefix path that leaked NTLM credentials, a PowerShell $PSDefaultParameterValues override, Git Bash following Cygwin symlinks, and a Linux sandbox protected-path escape; nested git repositories now require their own trust confirmation.

Streaming and Long-Session Responsiveness Fixes

Long responses no longer partly disappear or print twice while streaming, fullscreen sessions stay responsive because the conversation is no longer re-normalized on every update, and multi-second stalls after editing files with heavy IDE diagnostics are resolved.

From Anthropic

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