What changed
Anthropic released Claude Opus 5.5 on September 22, positioning it for agentic coding and knowledge work. Its claims need workload-specific evaluation.
Why it matters
A model upgrade can change how an agent plans, asks questions and calls tools, even when the API wrapper looks familiar. Those behavioural differences matter in a repository with production credentials or irreversible actions. Keep the model version and agent harness visible in evaluation records so a later regression can be traced.
What to check next
Run a small canary on reversible repository tasks. Compare patch quality, tool calls and escalation behaviour. Check current access and pricing in official documentation before committing. This retrospective reports the announcement; Codorc has not independently benchmarked the model.
Event dates refer to the original announcement. Publication dates show when this article first appeared on Codorc.
