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 v2.1.248 Home All releases olderv2.1.247 v2.1.250newer
Claude Code v2.1.248

Error detail is withheld when a session's output leaves the machine

You'll notice
Useful3 Signal3
Error Handling

When your transcript leaves this machine, many error messages print redacted and log detail locally.

What

When the session's transcript or output persists off this machine, many error messages now print without their detail and log the real detail locally instead. Slash-command dispatch, config key=value writes, MCP add/enable/reconnect, shell substitution in prompt commands, bash spawn failures, heap dumps, restarts and background session start all gained a redacted variant.

Details
  • Redacted messages carry the phrase "detail withheld on this connection".
  • Config writes now classify their outcome as kind: "save-failure" or kind: "refusal" rather than one generic failure.
  • Skill and command names and arguments are run through a sanitizer before being echoed into <local-command-stdout> and warning text.
  • Which sessions count as persisting off-box is decided by a per-session predicate whose definition is minified in the bundle, so remote, desktop and cloud coverage is not readable from the build.
Evidence

detail withheld on this connection

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

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.248 →