Strict reply-text validation is present behind the artifact comments gate, off by default.
What
Reply payloads must pass a strict content check, applied twice so that an approved payload is the one that actually gets sent.
Details
- Text must be non-empty, not visually blank after normalization, and at most 4096 UTF-8 bytes.
- The thread id must be UUID-shaped.
- Invisible, control, bidi and variation-selector code points are rejected, as are runs of exotic blanks; the check explicitly rejects most emoji.
- The same checks run in validateInput and again at call time, so hook or permission rewrites cannot substitute a different payload after approval.
- Behind the artifact-comments gate.
Evidence
text is visually blank — every approval surface would show an empty payload for it
Strings lifted out of the shipped bundle, so the claim above can be checked against them.