Unverified50% confidenceFactExact time
When Sonnet 5.5 acts as the executor, the advisor must be Opus 5, Opus 5.5, Sonnet 5.5, Fable 5/5.1 or Mythos 5/5.1; using Opus 4.8/4.7/4.6, Sonnet 5, Sonnet 4.6 or Haiku 5.5 as the advisor returns a 400.
1
Sources
50%
Confidence
Medium-term (~90 days)
Relevance
10/15/2026
First Seen
Valid until: 1/13/2027
Sources
Related Entities
Related Claims
UnverifiedSonnet 5 has switched to the tokenizer from Opus 4.7.78% similarPartially VerifiedSonnet 5.5 is on par with Opus 5.5 in offensive and defensive cybersecurity capabilities, making it the first model in the Sonnet series to adopt equivalent cybersecurity protection mechanisms.73% similarUnverifiedlangchain-anthropic 1.7.5 adds compatibility support for Claude Sonnet 5.5 (PR #40882).71% similarUnverifiedA similar Sonnet 5 leak (codenamed Phoenix) appeared in February of this year, but the model that was ultimately officially released was Sonnet 4.6, not Sonnet 5.70% similarUnverifiedAnthropic officially positions Sonnet 5.5 as an upgrade to Sonnet 5, with a 30% speed improvement and cost reductions of up to 30% for most workloads.69% similar
Cite This Claim
Stable URI
https://kongchang.com/claim/1033419API
curl https://kongchang.com/api/v1/knowledge/claims/1033419MCP
get_claim(id=1033419)