tengu_tool_memory_cgroup

A Claude Code feature flag, read out of the shipped bundle. It was in the build from v2.1.233 and was gone by v2.1.246.

Releases whose published page names tengu_tool_memory_cgroup.

1. v2.1.295 8 Oct 2026
   Memory limit for tool commands is skipped in a certain mode

   In a certain mode, Claude Code now skips setting up the memory limit it can place on commands run by tools

   gate cited by this entry

2. v2.1.246 25 Aug 2026
   Per-class memory caps on spawned processes, wired through but off for everything except Bash

   Memory limits now reach npm, git, tmux, LSP, MCP and hooks, but everything except Bash is excluded.

   gate cited by this entry, found in this entry's text

3. v2.1.246 25 Aug 2026
   Tool memory cgroups reworked, still off unless turned on

   Memory caps on processes Claude starts were rebuilt but stay off unless you set the limit variable.

   gate cited by this entry, found in this entry's text

4. v2.1.239 21 Aug 2026
   Per-tool memory limits detect an outer cgroup already in place

   On Linux, a tool already inside another tool's memory group is reported as nested instead of double-limited.

   gate cited by this entry, found in this entry's text

5. v2.1.233 14 Aug 2026
   Bash and PowerShell tools can run under a memory limit on Linux

   On Linux you can cap memory for shell commands so a runaway process cannot eat your machine.

   gate cited by this entry, found in this entry's text

Two arms, because they disagree: this account is the one account this site reads and anonymous is a baseline with no identity attached. A reading says nothing about your account, and off cannot rule out a rollout both readings sit outside of. What these readings can and cannot show.

One row per unbroken stretch of one reading, newest first, from snapshots taken every twenty-five minutes or so. No longer carried is not off: it means the flag server stopped returning the gate at all, which is what a retired experiment looks like. The version column is what was installed when the reading was taken, not what caused it.

The earliest release whose published evidence quoted tengu_tool_memory_cgroup was v2.1.246, 25 Aug 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.

One row per release since the first build this name was read out of. Absent means the build was read and the name was not in it, never mined means no bundle for that release was ever archived, and a declared type or a default is only ever what that release's own bundle stated.

Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the feature flag does. All feature flags.