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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.277 ·

Invisible and hidden characters are now stripped from prompts before sending

Pasted or typed text with invisible/hidden characters is now cleaned and flagged before it's sent, including in fleet composers

TierYou'll noticehow much it should matter to you
Useful2my rating, 1 to 5
Signal2worth watching, 1 to 5
AreaFleetwhat it touches
KindImprovementsin v2.1.277,
Group of 4 You'll notice No documentation found

Pasted or typed text with invisible/hidden characters is now cleaned and flagged before it's sent, including in fleet composers

What

  • Before a prompt is submitted, or before pasted text is sent, Claude Code now runs it through a filter that removes invisible characters, such as bidi marks, zero-width characters, hidden tags, and similar hidden selectors.
  • If any such characters are found, sending is blocked. Instead you see a notice like "Removed N invisible character(s) · review and press Enter to send" (or a message that nothing is left to send), and the text is replaced with the cleaned version so you can review it before sending again.
  • The same protection now applies to the fleet command bar and the fleet reply composer, not just the main prompt input.

Why

Invisible or hidden characters can be used to hide instructions inside pasted text or make it look different from what it actually contains. Stripping them and asking for confirmation before sending prevents accidentally sending something you didn't intend to.

Read from
Names in the bundletengu_prompt_invisible_strip

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