Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.221 Home All releases olderv2.1.220 v2.1.222newer

Bash sandbox prompt no longer promises $TMPDIR everywhere

You'll notice
Useful2 Signal0
Sandbox

Claude now makes its own scratch directory in sandboxed shells instead of assuming a temp variable exists.

$TMPDIRmktemp -d
What

The sandbox section of the Bash tool description now only tells Claude to use $TMPDIR when the sandbox actually exports it, and otherwise tells it to create its own scratch directory.

Details
  • the old "always use the $TMPDIR environment variable" text is kept when the helper returns true, meaning the platform is Windows or the sandbox profile is not "relaxed"
  • otherwise the model is told to make its own scratch dir with mktemp -d
  • so a relaxed non-Windows sandbox profile now gets the mktemp guidance
Evidence

the sandbox does not export it in this configuration

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.221 →