whats-new-sonnet-5 changedabout-claude/models/whats-new-sonnet-5
Nearest release: v2.1.238, published under an hour after this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Recorded here
Lines+1added
Lines−1removed
From line
121
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits5to this page, all time
The whole hunk
from line 121, old and new numbered
/
from line 121
121121
122122## Cybersecurity safeguards
123123
124Claude Sonnet 5 is the first Sonnet-tier model with real-time cybersecurity safeguards. Requests that involve prohibited or high-risk cybersecurity topics may be refused. Refusals return as a successful HTTP 200 response with `stop_reason: "refusal"`, not an error. See [Safeguards, warnings, and appeals](https://support.claude.com/en/articles/8241253-safeguards-warnings-and-appeals) for background.
124Claude Sonnet 5 is the first Sonnet-tier model with real-time cybersecurity safeguards. Requests that involve prohibited or high-risk cybersecurity topics may be refused. Refusals return as a successful HTTP 200 response with `stop_reason: "refusal"`, not an error. See [Real-time cyber safeguards on Claude Opus and Sonnet](https://support.claude.com/en/articles/14604842-real-time-cyber-safeguards-on-claude-opus-and-sonnet) for what the safeguards block and how legitimate security work can apply to the Cyber Verification Program.
125125
126126## Pricing
127127
No line in this hunk matches that.