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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 v2.1.251 Home All releases ←olderv2.1.250
Claude Code v2.1.251

Invisible character runs in file output are withheld rather than displayed

You'll notice
Useful3 Signal3
File Tools

File output with long runs of invisible characters is withheld instead of printed.

What

Text shown by Grep, Read and related tools passes through a sanitizer that caps how many invisible and variation-selector characters can run together on one line. If the text would have to be altered, it is shown as withheld content with a marker instead of being printed verbatim, which blocks hidden instructions smuggled into files.

Details
  • runs on all matched file content, unconditionally
  • the marker stands in place of the offending text so you can see something was suppressed
Evidence

kind: "withheld", marker: lO(lU)

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 v2.1.251 →