Source Intelligence
Reading a new release v2.1.251 Analysing changes · 2/5 Sorting the findings · 1/4 steps 470 findings $18.91 so far

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 v2.1.200 Home All releases olderv2.1.199 v2.1.201newer

set_cwd SDK Tool

What

New programmatic working-directory change mechanism for SDK hosts (e.g. Claude Desktop) — the headless twin of the interactive /cd command.

Details
  • Accepts path (required), trust_accepted (boolean), and trusted_directory (required if trust_accepted is true)
  • Runs the same validation, Cd(...) permission rules, and relocation path as the interactive /cd
  • Returns structured responses: ok (with cwd, changed, transcript_relocated), needs_trust (when the directory requires a trust dialog), or rejected (with reason: busy, not_found, not_a_directory, blocked_by_rule, unsafe_path)
  • Rejects requests while a turn is in progress with a clear "busy" reason
  • The trust_accepted flow requires echoing back the exact directory string from the needs_trust response to pin the attestation
  • Paths containing invisible or non-printing characters are rejected as unsafe
Evidence

New set_cwd handler (search for "A turn is in progress — the working directory can only change", "set_cwd: invalid request — path must be a non-empty string", "set_cwd: invalid request — trust_accepted requires trusted_directory")

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

See this entry in the whole of v2.1.200 →