Group of 2 You'll notice
Claude Code now blocks tool calls that fake internal __artifact-prefixed argument keys, except for tools allowed to set them
What
- Tool calls whose arguments include a key beginning with
__artifactare now denied unless the tool is recognized as one that legitimately mints such keys, with the message "Nothing was done. The arguments carry a key that only Claude Code sets." - This relies on a new
mintsArtifactKeys()capability check, which is also used to suppress certain artifact-related event logging for contexts that mint their own artifact keys.
Why
This prevents a model or malicious input from spoofing internal artifact bookkeeping keys that only Claude Code itself is meant to set.